CVIndependent

Sat11172018

Last updateTue, 18 Sep 2018 1pm

It’s planetfest, with five bright planets in July’s evening hours! Three of them far outshine all stars. (But early in the month, you must wait until after nightfall to see Mars.)

Venus, the brightest, gleams at magnitude -4.1 to -4.3 in the west at dusk, and sets more than two hours after sunset. Jupiter glows at magnitude -2.3 to -2.1 in the south to south-southwest at dusk. Mars rises in the east-southeast to southeast two hours after sunset on July 1, one hour after sunset on the 16th, and at sunset on the 31st. Earth overtakes Mars on the night of July 26, passing within 35.8 million miles four nights later, on the night of July 30-31. This is our closest approach to Mars since 2003, and the nearest until 2035. As Earth approaches Mars in July, the red planet attains rare brilliance, kindling from magnitude -2.2 to -2.8, to outshine Jupiter until early September.

Mercury shines at zero magnitude first for the few days and lingers very low in the west-northwest twilight glow, to the lower right of Venus, within 16-17 degrees July 1-15, and widening to 20 degrees away by July 20, when it fades to magnitude +1. Saturn, of magnitude 0.0 to +0.2, ascends through the southeast toward the south-southeast at dusk, reaching its high point in the south about 4.5 hours after sunset on July 1, backing to 2.6 hours after sunset on the 31st.

The most prominent stars, also of magnitude zero, are golden Arcturus, high in the south-southwest to west-southwest, and blue-white Vega, high in east-northeast. Vega is a member of the Summer Triangle along with Altair and Deneb, up all night throughout July.

Morning: Mars is by far the brightest “star” in morning twilight, sinking low in the southwest as the month progresses. In the first week, note Saturn very low in the west-southwest, 34 degrees to Mars’ lower right. The two brightest real stars are Vega in west-northwest to northwest, and Capella, climbing in the northeast. Other stars visible in morning twilight include Altair and Deneb, completing the Summer Triangle with Vega; Aldebaran, eye of Taurus, in the east to east-northeast to the lower right of Capella; and Fomalhaut, in the south to south-southwest. Rising into view late in the month are Rigel and Betelgeuse, right and left of Orion’s belt low in the east; and Castor and Pollux of Gemini, well north of east.

July features four telescopic showpiece planets: Venus in July displays a gibbous phase, 70 to 57 percent full. The view will be more impressive in August through January, as Venus goes through half and crescent phases—larger than now in apparent size, because Venus will be closer to Earth. Jupiter shows cloud belts and up to four bright moons discovered by Galileo. Saturn shows rings still tipped a generous 26 degrees into our view, and satellite Titan in its 16-day orbit. Mars this month shows a prominent south polar cap of frozen carbon dioxide, shrinking with the advance of southern spring—catch it soon!—and surface features, such as Syrtis Major and Hellas Basin.

For events at dawn, begin viewing at least one hour before sunrise. For events at dusk, look one hour after sunset except when noted.

July 1: At dawn, in the south-southwest, find bright Mars within 7 degrees to the lower right of the waning gibbous moon. At dusk, find four planets: Mercury very low in the west-northwest, 17 degrees to the lower right of brilliant Venus; Jupiter well up in the south; and Saturn low in southeast. Tonight, Venus to Saturn span nearly 135 degrees. About two hours after sunset, watch for bright Mars rising in the southeast, and another 40 minutes later, watch for the waning gibbous moon rising 16 degrees to the lower left of Mars.

July 2-12: At dusk, Mercury, our solar system’s innermost planet, stays 16 degrees to the lower right of Venus. If you always look exactly one hour after sunset, Mercury will appear highest, nearly 6 degrees up, on July 4, and will reach greatest elongation, 26 degrees from the sun, a week later, on July 11. But Mercury is fading from magnitude 0.0 on July 1 to magnitude +1.0 on July 20, getting fainter each night as Mercury sinks into bright twilight.

July 5, 1 to 1 1/2 hours after sunset: The star Regulus, heart of Leo, is within 5 degrees of Venus for nine evenings through July 13, fitting within the same field of view of most binoculars. Watch nightly as Venus moves just more than one degree per day, and passes one degree north (to the upper right) of Regulus on July 9. For a few days, you can easily detect Venus’ change in position from one day to the next.

July 9, 1 to 1 1/2 hours before sunrise: Find the waning crescent moon (18 percent) just north of east, with the Pleiades star cluster 10 degrees to its upper left, and bright Aldebaran, eye of Taurus, within 13 degrees to the moon’s lower left. Look the next morning, July 10, at the same hour, to catch the moon within 2 degrees to the lower left of the star, and the Hyades star cluster nearby.

July 9, 2 to 1 1/2 hours after sunset: Venus and Regulus appear closest tonight, just 1 degree apart. Jupiter ends retrograde 2.1 degrees west of third-magnitude Alpha in Libra (Zubenelgenubi), and begins creeping back toward that star.

July 10: See four planets simultaneously in the evening sky. You have two choices; select a viewing site where mountains won’t block your view. 1. About one hour after sunset, look west to west-northwest for brilliant Venus 16 degrees up, with Mercury 16 degrees to its lower right and 5 degrees above the horizon. Jupiter is then 40 degrees up in the south to south-southwest, and Saturn is about 20 degrees up in the southeast. 2. Look nearly two hours after sunset, when Venus and Mars are 5 degrees above opposite horizons. Find Venus low in the west to west-northwest; Jupiter in the south-southwest; Saturn in the southeast to south-southeast; and Mars low in the east-southeast to southeast.

July 11: Your last chance to see the old moon in this cycle. One hour before sunrise, look very low in the east-northeast for the slender 4 percent crescent. The new moon occurs on July 12 at 7:48 p.m., with a partial solar eclipse visible in southeast Australia and the ocean to the south.

Nights of July 12-19: Observe Mars’ south polar cap soon, while it is still large, and before a possible planet-wide dust storm that could render it invisible! The Martian south polar cap, where spring began on May 22, in July is tipped 10-17 degrees toward the sun and a favorable 14 to 11 degrees into our view from Earth. The frozen-carbon-dioxide polar cap is now shrinking from its maximum extent. Using your telescope with as high of a magnification as atmospheric conditions allow, look for a large bright area near the southern edge of Mars’ reddish disk. On the nights of July 12-19, the prominent dark mark, Syrtis Major—first recorded with certainty in early telescopic observations by Christiaan Huygens in 1659—will appear near the center of the Martian disk on July 12 at 11:36 p.m., and about 36-37 minutes later each successive night, i.e., July 14 at 12:12 a.m., July 15 at 12:49 a.m., until July 20 at 3:51 a.m. Around these times, Mars is well-placed in our sky for telescopic observation. Catch views of Syrtis Major up to two hours away from those times, provided Mars isn’t too low.

July 13, in early dusk: About 25 minutes after sunset, look for the slender 2 percent crescent about 3 degrees up in the west-northwest, some 29 degrees to the lower right of Venus and 13 degrees to the lower right of Mercury. Tonight, Venus, Jupiter and Saturn span 120 degrees.

July 14, one hour after sunset: The crescent moon, 6 percent full, is very low in the west to west-northwest, with Venus 15 degrees to the upper left, and Mercury within 3 degrees below and a little to the right. Regulus is within 6 degrees to the lower right of Venus.

Sunday, July 15, at dusk: Don’t miss this spectacular sight! One hour after sunset, Venus is only about one degree to the left of the 13 percent crescent moon. Regulus and Mercury are about 7 and 17 degrees to the lower right of Venus. If you have an unobstructed horizon, keep Mercury in view as it sinks lower, toward the west-northwest horizon. If nothing blocks your view, then you may be able to spot Mars before Mercury sets some 16 degrees north of west. From places near our Coachella Valley, the best time to look is about 1.2 hours after sunset. If you spot Mars before Mercury disappears, that makes five planets in view simultaneously! If surrounding mountains prevent you from doing this, then note Mercury-Venus-Jupiter-Saturn in west to east order in the early evening, before Mercury sets; then wait awhile until Mars rises, and you’ll see Venus-Jupiter-Saturn-Mars spanning 150 degrees.

July 16 at dusk: Face west for the 22 percent crescent moon, and Venus within 13 degrees to its lower right. Mercury is 18 degrees to the lower right of Venus. Using binoculars, try for Regulus 8 degrees to the lower right of Venus and 10 degrees to the upper left of Mercury. If you’re trying for all five bright planets, the best time to look is about 1 hour, 9 minutes after sunset, when Mars will have just risen about 30 degrees south of east; Jupiter will be well up in the south-southwest, and Saturn will be 33 degrees to the upper right of Mars. If you spot Mars before Mercury sets, you’ve got it!

July 17: If you have an unobstructed horizon, you can spot six solar system bodies with the unaided eye about 1.1 hours after sunset. In order from west to east, they are Mercury, Venus, the moon, Jupiter, Saturn and Mars. Otherwise, look earlier to catch Mercury before it sets, or look a few minutes later to see Mars after it rises, and you’ll still see five bodies at once! Mercury is getting fainter nightly and lower in twilight.

July 18: In order from west-northwest to east-southeast, nine bright objects lie along the zodiac and above the horizon just more than an hour after sunset tonight: Mercury, Regulus, Venus, a fat crescent moon with Spica 9 degrees to its lower left, Jupiter, Antares; Saturn and Mars. With mountains surrounding us, we are not likely to see Mercury and Mars simultaneously. Look a few minutes earlier for Mercury, or later to spot Mars after it rises.

July 19: Early this evening, the moon has passed its first quarter phase, so it’s slightly more than half full (54 percent), and more than 90 degrees (94, to be exact) east of the sun.

July 20: One hour after sunset, bright Jupiter is just 3-4 degrees to the lower right of the waxing gibbous moon, nearly two-thirds full. Today is the 49th anniversary of the first manned lunar landing, Apollo 11.

July 21: One hour after sunset, the moon is nearly three-fourths full, just west of due south. Jupiter is about 14 degrees west of the moon. Antares, heart of the Scorpion, is 16 degrees to the moon’s lower left. Venus and Jupiter are 60 degrees apart tonight.

July 22 at dusk: Antares is 8 degrees below the moon.

July 23 at dusk: Reddish twinkling Antares is 14 degrees to the moon’s lower right. Steady, yellowish Saturn is 13 degrees to the moon’s lower left.

July 24 at dusk: Saturn is a little more than one degree below the moon’s lower edge. You’ll have no difficulty seeing it if you block the moon with your hand. Note bright apricot-colored Mars 32 degrees to the moon’s lower left.

July 25 at dusk: Saturn is 11 degrees to the moon’s upper right. Brilliant, tawny-colored Mars, gleaming at magnitude -2.8, is within 21 degrees, to the lower left of the moon.

Night of Thursday, July 26: Mars is at opposition tonight as Earth overtakes the red planet and we look almost directly away from the sun to see it. One hour after sunset, look low in the southeast to find Mars within 10 degrees to the lower left of the nearly full moon. Mars is now several degrees south of Earth’s orbit plane, so an hour before sunrise on Friday, July 27, they’re still 8 degrees apart, 8 degrees up in the west-southwest, with Mars to the moon’s left. The moon isn’t then yet at opposition; there are still several hours to go before a deep total lunar eclipse, when the moon at mid-event will be directly overhead of the Indian Ocean just east of Madagascar. It’s daytime then in California, July 27 at 1:22 p.m., with the moon well below our horizon, so none of the eclipse will be seen in North America. We’ll have our chance to see a total lunar eclipse on the evening of Jan. 20, 2019.

Night of Friday, July 27: The moon, several hours past full, rises 6 minutes after sunset. About 10 minutes later, watch for the rising of Mars about 7 degrees to the moon’s right. One hour after sunset this evening, Mars is just 7 degrees up in the southeast, and 7-8 degrees to the moon’s upper right. By an hour before sunrise on Saturday, July 28, Mars is 7 degrees up in the southwest, 9-10 degrees below the moon. Mars sets about 14 minutes before sunrise.

Night of Monday, July 30: Tonight, at 12:50 a.m. on Tuesday, Mars has its closest approach to Earth since August 2003, and the closest until September 2035. Mars is within 35.8 million miles of Earth, and it takes the light reflected off the surface of Mars only 3.2 minutes to reach us. For sky watchers in Palm Springs, Mars reaches its high point in the sky at 12:44 a.m., while 30 degrees above the southern horizon.

The website of the Astronomical Society of the Desert  has a listing of our evening star parties. Sawmill Trailhead (SMT), our high-altitude site (elevation 4,000 feet) will have a star party starting at dusk on Saturday, July 14.

Abrams Planetarium publishes a monthly Sky Calendar with an evening sky map. Subscriptions are $12 per year. Subscribe or view a sample issue at www.abramsplanetarium.org/skycalendar.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

At dusk in June, two planets clearly outshine all the stars. Venus, at magnitude -4 in the west-northwest, sets about 2.5 hours after sunset. Jupiter, near magnitude -2.4 in the southeast to south at dusk, reaches its highest point in the south about three hours after sunset on June 1, moving to one hour after sunset at month’s end.

Mercury passes superior conjunction on the far side of the sun on June 5. Near the perihelion of its orbit, it emerges very swiftly into the evening sky. Using binoculars, look very low in the west-northwest twilight glow, to the lower right of Venus, by 25 degrees on June 16; 20 degrees on June 25; and 17 degrees on June 30.

Later in the evening, Saturn rises within two hours after sunset on June 1, moving to around sunset on June 24, three days before opposition. Mars rises within four hours of sunset on the 1st, moving to about two hours after on the 30th. Find the Summer Triangle in the eastern sky at dusk as the season begins.

During June mornings:Jupiter on June 1 sets in the west-southwest nearly 1.3 hours before sunrise, and then 4 minutes earlier each morning. If your predawn walk occurs after Jupiter sets, you’ll see a sky dominated by Mars, in the south to south-southwest, while brightening nearly a magnitude, from -1.2 to -2.1. Saturn, near magnitude 0, is lower in the southwest, 28 to 34 degrees west of Mars. Prominent stars include the Summer Triangle, passing west of overhead; Fomalhaut in the southeast to south; Capella rising from the northeast; and Aldebaran emerging late in the month in the east-northeast.

This month features bright visible outer planets! On the morning of June 1, Spaceship Earth is heading toward constellation Aquarius, about 35 degrees to the east (left) of Mars. As our planet follows its nearly circular orbit around the sun, we overtake all three bright outer planets within 79 days, the shortest interval until 2078.

The asteroid Vesta> was the fourth to be discovered, in 1807. This month provides chances to see this asteroid with binoculars—and even the unaided eye in very dark skies. Begin with this finder chart which shows seven of the eight stars of the Teapot of Sagittarius. On the night of June 4, a line 5.7 degrees long, from 2.8-magnitude Lambda Sgr (Kaus Borealis, atop the Teapot’s lid) to 3.9-magnitude Polis (Mu Sgr), extended three degrees past Polis, ends near Vesta, magnitude 5.7. Vesta is retrograding in June, changing its place by about one-quarter of a degree daily for the rest of the month. Note the open cluster M23 within 2.5 degrees west of Vesta on June 4. On June 14, Vesta will pass closely southeast of M23. For a few days around its opposition on June 19, Vesta will reach magnitude 5.3, brighter than it will be again until July 2029.

For events at dawn, we suggest you begin viewing at least one hour before sunrise. For events at dusk, look one hour after sunset except when noted.

June 1 at dawn: The moon, nearly three days past full, is in the south-southwest at dawn, 5 degrees east (to the upper left) of Saturn and 23 degrees west (to the lower right) of Mars. Evening: Try to spot Saturn rising before Venus sets. Both are 4 degrees above opposite horizons about 2.2 hours after sunset. Three hours after sunset: The moon, just risen in the east-southeast, is 15 degrees to the lower left of Saturn.

June 2 at dawn: The waning gibbous moon is in the south to south-southwest, with Mars 12 degrees to the left, and Saturn 17 degrees to the lower right. Four hours after sunset: The moon, very low in the east-southeast, has Mars within 3 degrees to its lower right, and Saturn 27 degrees to its upper right.

June 3 at dawn: The moon is in the south, with Mars 2-3 degrees below. Saturn is 29 degrees to the lower right of the moon.

June 6-8 at dusk: A week after forming an isosceles triangle with the “Twin” stars Pollux and Castor, Venus now passes within 5 degrees to the lower left of Pollux. Look nightly, and see Venus move!

June 7-12, before dawn: The Martian south polar cap, where spring has recently begun, is now tipped 4-5 degrees toward the sun and a favorable 15 degrees into our view from Earth. The frozen carbon-dioxide polar cap is still near its maximum extent. Using your telescope with as high of a magnification as atmospheric conditions allow, look for a large bright area near the southern edge of Mars’ reddish disk. These mornings, the prominent dark marking Syrtis Major, the first Martian feature to be recorded in early telescopic observations, will appear near the center of the Martian disk on June 7 at 1:43 a.m., and about 38 minutes later each successive morning, until 4:54 a.m. on June 12. Around these times, Mars is well-placed in our sky for telescopic observation. Catch views of Syrtis Major up to two hours away from those times, provided Mars isn’t too low, or you don’t run into daylight.

June 11 at dawn: The moon is very low in the east-northeast to east. Use binoculars to spot the Pleiades cluster 15 degrees to the left of the rising moon.

June 12, 35 minutes before sunrise: Try to find the very old, thin crescent moon, 3 percent full, less than 3 degrees up, 17 degrees north of east.

June 13: The new moon, arriving at 12:43 p.m. is not visible today, neither at dawn nor at dusk.

June 14, 30 minutes after sunset: The crescent moon, some 32 hours old and 3 percent full, is 6 degrees up the in west-northwest. The moon sighting marks the end of Ramadan. Binoculars show Mercury 8 degrees to the moon’s lower right. Venus is easy to see with the unaided eye, 20 degrees to the moon’s upper left.

June 15, 30 minutes after sunset: The 8 percent crescent moon is 18 degrees up in the west to west-northwest, with Mercury 20 degrees to its lower right. Venus is within 7 degrees to the moon’s upper left.

June 16, beginning 30 minutes after sunset: The moon, at 16 percent, is well up in west, with Venus and Mercury 8 degrees and 33 degrees to the moon’s lower right. Mercury now sets a full hour after the sun.

June 17 at dusk: Regulus, heart of Leo, is within 4 degrees to the moon’s upper left. Mercury is 24 degrees to the lower right of Venus.

June 18 at dusk: Regulus is 11 degrees to the lower right of the moon.

June 19: The moon, nearing first-quarter phase, is almost 90 degrees east of the sun in the afternoon and evening sky, and appears almost half full. In the late afternoon, view or photograph the moon through a polarizing filter, rotating it to darken the blue sky, and you’ll improve the contrast well enough to observe lunar craters in the daytime! At dusk, Mercury forms an isosceles triangle with “Twin” stars Pollux and Castor 10 degrees above the planet. As twilight deepens, binoculars and telescope show the Beehive star cluster closely south of Venus.

June 20 at dusk: Can you see Saturn rising before Mercury sets? Both are nearly 5 degrees above opposite horizons at mid-twilight, 47 minutes after sunset. That makes four planets, Mercury-Venus-Jupiter-Saturn, visible simultaneously!

June 21 at 3:07 a.m.: The sun stands directly over the Tropic of Cancer, and summer begins for Earth’s Northern Hemisphere, with the shortest night and longest day. In Palm Springs, 12:48 p.m., the sun passes only 10.4 degrees south of overhead. Set up an Earth globe outdoors with your city at the top of the sphere, and the directions matched up, and your globe will have the same orientation as the Earth in space. Its axis will point nearly to the North Star, and the sunlit portion of the globe at any time of day you look will match reality. Note the North Pole is tipped into sunlight, and the South Pole is tipped into darkness.

June 21 and 22 at dusk: Spica in Virgo appears within 7 degrees to the lower left, and then 13 degrees to the lower right, of the waxing gibbous moon. On June 22, Jupiter appears within 10 degrees to the moon’s lower left.

June 23 at dusk: Jupiter is 5 degrees to the lower right of the moon. Mercury is 20 degrees to the lower right of Venus and closing.

June 24 at dusk: Mercury passes within 5 degrees to the south (lower left) of Pollux. Jupiter is 17 degrees to the moon’s upper right. On June 24 and 25 at dusk, Venus and Jupiter are about 90 degrees apart. Watch them draw together until late September, when they’ll be within 14 degrees.

June 25 at dusk: Antares, heart of Scorpius, is 8-9 degrees to the moon’s lower right.

June 26 and 27 at dusk: Mercury forms a nearly straight line with Pollux and Castor to its right. Saturn is 11 degrees to the moon’s lower left on June 26, and 1-2 degrees to the right of the full moon on June 27.

June 28 at dawn: The moon, just past full, is in the southwest, with Saturn, a day past opposition, 3-4 degrees to the moon’s lower right. At dusk, Saturn is within 13 degrees to the upper right of the moon.

June 30 at dawn: Mars is within 8 degrees to the left of the moon. On evening of June 30, Venus, Jupiter and Saturn span 135 degrees. Can you spot Mars before Venus sets? You’ll need a good vantage point; both are 2 degrees above opposite horizons about 2 1/4 hours after sunset.

The website of the Astronomical Society of the Desert at www.astrorx.org has a listing of our evening star parties. Sawmill Trailhead, our high-altitude site (elevation 4,000 feet), will have a star party starting at dusk on Saturday, June 9.

Abrams Planetarium publishes a monthly Sky Calendar with an evening sky map. Subscriptions are $12 per year. Subscribe or view a sample issue at www.abramsplanetarium.org/skycalendar.

Wishing you clear skies!

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

The two brightest “stars” in the April evenings are really planets. Venus continues to gain altitude in the west to west-northwest at dusk, as the time of its setting shifts from 1.6 hours after sunset on April 1, to 2.2 hours after on the 30th. Jupiter doesn’t appear on our evening mid-twilight chart until almost month’s end; it rises in east-southeast just more than three hours after sunset on the 1st, to just more than a half-hour after on the 30th.

Next in brilliance at dusk are blue-white Sirius in the southwest; golden orange Arcturus climbing in the east-northeast to east; and yellow Capella, high in the northwest.

In the morning, Jupiter, in the southwest at dawn, is easily the brightest morning “star.” Ranking next are Arcturus in west, and Vega passing just a few degrees north of overhead. Mars, just east of due south, is slightly fainter than these stars as April begins. But as Earth closes its distance to Mars—from 103 million miles on the 1st to 79 million miles on the 30th—the planet begins to outshine those stars. In early April, Mars is closely accompanied by Saturn; they appear closest, within 1.3 degrees, on April 2. By month’s end, Mars-Saturn are 14 degrees apart.

Other bright stars in the morning sky are Altair and Deneb, completing the Summer Triangle with Vega; Antares, between Jupiter and Saturn, but below the line joining these two giant planets; and Spica, sinking in the west-southwest, to the lower right of Jupiter and lower left of Arcturus. On April 13, Spica is at opposition as the Earth passes between that star and the sun. On April 13-14, look for Spica in the east-southeast at dusk, well up in south in middle of night, and low in the west-southwest at dawn. Mercury, brightening slowly from magnitude +1.0 to +0.4 during April 19-30, is very low in the east in dawn twilight. In this poor apparition, binoculars are recommended.

On the morning of April 2, Spaceship Earth is heading toward a direction in space within 4 degrees east (to the left) of the Mars-Saturn pair. As our planet follows its nearly circular orbit around the sun, we will overtake all three bright outer planets, and each will take its turn at opposition and all-night visibility: Jupiter on May 8, (Antares on May 31), Saturn on June 27, and Mars on July 26. Mars, the next planet outward from Earth, will brighten spectacularly in July, outshining even Jupiter.

For events at dawn, the suggested viewing time is generally one hour before sunrise. For events at dusk, look one hour after sunset, except when noted.

Easter Sunday, April 1, at dawn: Spica is 6 degrees south of the moon in the west-southwest. Jupiter is in the south-southwest to southwest, 29 degrees to the upper left of the moon. The Mars-Saturn pair is in the south-southeast, 1.4 degrees apart, about 46 degrees left of Jupiter.

April 2 at dawn: Mars passes within 1.3 degrees south of (below) Saturn; the pair is 47 degrees east (left) of Jupiter. Red supergiant star Antares, heart of the Scorpion, is 19 degrees to the lower left of Jupiter and 29 degrees to the lower right of Mars.

April 3 at dawn: Mars-Saturn are 1.4 degrees apart. Jupiter is within 4 degrees to the lower left of the moon in the southwest. Four hours after sunset: The moon is low in the east-southeast, within 9 degrees to the lower left of Jupiter.

April 4 at dawn: Jupiter is 11 degrees to the lower right of the moon; Antares is 11 degrees to the lower left of the moon.

April 5 at dawn: Antares is within 10 degrees to the lower right of the moon. Mars-Saturn are 2 degrees apart.

April 6 at dawn: Mars-Saturn are 2.4 degrees apart, 12-14 degrees east (to the left) of the moon. Four solar system bodies—in order from west to east, Jupiter, the moon, Saturn and Mars—span 49 degrees.

April 7 at dawn: A beautiful gathering of the moon and two planets fits within the field of view of binoculars: Saturn about 1 degree to the moon’s lower right, with Mars just more than 3 degrees to the moon’s lower left.

Sunday, April 8 at dawn: The moon, in the south-southeast, has just passed last quarter phase and appears slightly less than half-full. All three bright morning planets are now west of the moon—Mars and Saturn by 9 and 12 degrees, respectively, and Jupiter by 59 degrees.

April 9 at dawn: Mars-Saturn are 4 degrees apart, 20 to 24 degrees to the upper right of the fat crescent moon.

April 11 at dawn: Mars-Saturn are 5 degrees apart.

April 12 at dawn: The distance from the crescent moon, low in the east-southeast, to Jupiter, in the southwest, spans 108 degrees. Dusk: Venus appears 15 degrees directly below the Pleiades star cluster, aka the Seven Sisters.

April 13 at dawn: This the last easy chance to view the waning crescent moon, rising within 10 degrees south of east in twilight; Spica is at opposition in the west-southwest. Between them, find Jupiter in the southwest, and Saturn and Mars 6 degrees apart in the south to south-southeast. At dusk: Find Spica low in the east-southeast. When Spica passes due south in the middle of night, look 36 degrees below it and only 3-4 degrees up for the globular cluster Omega Centauri, some 17,000 light-years away. Seen through binoculars in very dark skies, it appears as a round, fourth-magnitude fuzzy ball about as large as the moon.

Sunday, April 15: The new moon, closely south of the sun at 6:57 p.m., is invisible today!

April 16, about 25-40 minutes after sunset: From a place with an unobstructed view, some 10 degrees north of west, try to see the thin crescent moon, very low—2 to 5 degrees above the horizon—within 13 degrees below and slightly left of Venus. The moon’s age is about 25 hours past new. As the sky darkens, look for the Pleiades cluster 10 degrees above Venus. Binoculars give best views of the moon and of Pleiades.

From places with unobstructed views toward the east-southeast and west-northwest, Jupiter now rises just 8 minutes before Venus sets, and it is briefly possible to observe both planets simultaneously above opposite horizons. By April 24, Jupiter will rise one hour before Venus sets, so it will become easier to do so. By April 30, Jupiter will rise 99 minutes before Venus sets. It remains possible to observe these two bright planets simultaneously at dusk until early October, when Venus sinks into twilight.

April 17 at dawn: Mars and Saturn are 8 degrees apart. At dusk: Venus appears within 6 degrees to the right of the crescent moon, with earthshine illuminating the moon’s dark side.

April 18 at dusk: Don’t miss this special, beautiful sight! Within an hour after sunset, the moon is framed by the V-shaped head of Taurus, the Bull, composed of bright Aldebaran (marking the Bull’s eye 67 light years away, within 2 degrees to the moon’s upper left), and the fainter remaining stars of the “V,” members of the more distant Hyades cluster. Watch the moon close in on Aldebaran as the evening progresses. By 10 p.m., the star appears just 1 degree to the upper left of the moon’s center.

April 19 at dusk: Pleiades is 7 degrees to the upper right of Venus, with Aldebaran 13 degrees to the lower right of the moon.

April 20 at dusk: Betelgeuse, shoulder of Orion, is 15 degrees to the lower left of the moon. Below Betelgeuse, look for Orion’s three-star belt, and still lower, Orion’s foot, Rigel. Look for these stars each evening within an hour after sunset in coming weeks, and watch for their annual departures below the western horizon.

April 21 at dawn: Mars and Saturn are 10 degrees apart. Dusk: Pleiades is 5 degrees to the upper right of Venus. Pollux is 9 degrees to the upper right of the moon, with Procyon 15 degrees to the moon’s lower left.

Sunday, April 22, predawn darkness hours: It’s the peak of the Lyrid meteor shower. In early afternoon, the moon passes first quarter, 90 degrees east of the sun, and appears half full. In the late evening, the moon passes 2 degrees south of the Beehive cluster. You’ll need binoculars or a telescope to see the cluster’s stars so close to the moon.

April 23 at dusk: Regulus is 10 degrees to the lower left of the moon. Venus is within 4 degrees south (lower left) of Pleiades.

April 24 at dawn: Three bright outer planets—from west to east, Jupiter, Saturn and Mars—span 60 degrees. Mercury is also visible, very low in the east. Dusk: Regulus, heart of Leo, the Lion, is 4 degrees to the moon’s upper right. Venus’ least distance from Pleiades occurs tonight, as the planet passes 3.5 degrees south of the cluster’s brightest member.

April 25 at dusk: Pleiades is 4 degrees to the right of Venus, with Aldebaran 10 degrees to Venus’ upper left.

April 26 at dusk: Venus is nearly on line, joining Pleiades and Aldebaran.

April 27 at dusk: Spica is 11 degrees to the lower right of the moon.

April 28 at dusk: Spica is 8 degrees to the right of moon and a little higher. Watch for Jupiter rising 21 degrees to the lower left of the moon.

Sunday, April 29 at dusk: Venus is equidistant from Pleiades and Aldebaran—7 degrees from each. The full moon is 19 degrees to the lower left of Spica and 8 degrees above Jupiter.

April 30 at dawn: Jupiter is 5 degrees to the left of the moon in the southwest to west-southwest. Mars-Saturn are 14 degrees apart in the south-southeast to south. At dusk, watch for moonrise 6 degrees to the lower left of Jupiter in the east-southeast.

The website of the Astronomical Society of the Desert  has a listing of our evening star parties at two locations. The primary, more accessible location is at the visitor center of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). A sky viewing session is scheduled there on Saturday, April 21, from 8 to 10 p.m. Sawmill Trailhead, our high-altitude site (elevation 4,000 feet), will have a star party starting at dusk on Saturday, April 14. Listings of star parties on the website include maps and directions for both locations. Star parties can be cancelled in poor observing weather. Also, check link to “Impromptu Star Parties” on that website for star parties announced on short notice.

Robert Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for a variety of groups in the Coachella Valley. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

November 2017 features twilight planetary pairs—one in the morning, and one in the evening.

Venus and Jupiter will appear close together low in the east-southeast morning twilight glow for a few mornings around Nov. 13, about 40-45 minutes before sunrise. In last 10 days of the month, Saturn and Mercury will appear within the same binocular field low in the southwest evening twilight glow, 40-45 minutes after sunset.

Of the morning planets, dim, distant Mars rises in a dark sky all month, improving from 2.6 hours before sunup on Nov. 1, to 3.5 hours at month’s end. Mars glows at magnitude +1.8 to +1.7, about as faint as it ever gets. Brilliant Venus, of magnitude -3.9, rises in ever brighter twilight, 1.3 hours before sunup on the 1st, and about 45 minutes hour before sunup on the 30th. Watch for Venus’ rising 16 to 34 degrees to the lower left of Mars as November runs its course.

On Nov. 2, binoculars readily show the star Spica rising in the twilight glow 3.5 degrees to the lower right of Venus. The other morning planet, Jupiter, at magnitude -1.7, is lost in the sun’s glare well below Venus in first few days, but from Nov. 8-18, may be found in the same binocular field as Venus. The two bright planets appear closest on Monday, Nov. 13, with Jupiter just one-third of a degree to the upper right of Venus. This month, on Nov. 29, Jupiter will rise in a dark sky just more than two hours before sunrise. As Venus rises in twilight that morning, Jupiter will appear 17 degrees to the upper right of Venus and 17 degrees to the lower left of Mars, midway between them.

Bright stars in morning twilight feature the huge Winter Hexagon of bright stars moving into the west. Sirius, the Dog Star, is its brightest and southernmost member. Orion’s red Betelgeuse lies inside the Hex, and Leo’s Regulus, high in the south-southeast to south, trails behind it. Bright Arcturus in the east-northeast to east, and Spica in the east-southeast to southeast, round out the list of 10 stars of first magnitude or brighter visible in all of November’s dawns. An 11th star, Vega, rises in the northeast late in the month, far to the lower left of Arcturus.

Around Nov. 21, our Spaceship Earth is heading directly toward the star Regulus. Go outdoors in the morning, and visualize our planet’s motion around the sun, and the motions of faster-moving Venus, the next planet inside Earth’s orbit, and slower-moving Mars and Jupiter, the planets next outside our orbit. If we could look “down” from “above” the solar system, the planets would appear to revolve counterclockwise around the sun. All the morning planets are ahead of us. Venus is moving even farther ahead, and will pass on the far side of the sun in January 2018. We’re gaining on Jupiter and Mars, and will overtake them next year.

Bright stars in evening twilight in all of November include the Summer Triangle, with Vega, Altair and Deneb passing west of overhead; and Fomalhaut, mouth of the Southern Fish, low in the southeast to south-southeast. Quickly slipping out of view early in the month are Antares, in the southwest to the lower right of Saturn, and Arcturus, in the west-northwest. Rising into view are Capella in the northeast, and Aldebaran in the east-northeast.

Evening planets: Saturn (magnitude +0.5) on Nov. 1 sets in a dark sky 2.7 hours after sunset, and telescopes reveal its rings tipped as much as possible, 27 degrees from edgewise. But Saturn sets ever earlier, sinking close to brighter Mercury (magnitude -0.4 to -0.1) in the latter half of the month. Mercury appears to the lower right of Saturn, by 10 degrees on Nov 17, and 7 degrees on Nov. 20. On Nov. 23, Mercury reaches greatest elongation—22 degrees from the sun and 4.7 degrees below Saturn. Thereafter, Mercury appears to the lower left of Saturn, by 4 degrees on Nov. 24, and 3 degrees on Nov. 28. This is quite an unfavorable appearance for our solar system’s innermost planet, as it remains mired low in twilight.

The moon is full on Friday, Nov. 3, and rises north of east a few minutes after sunset. Two nights later, on Sunday, Nov. 5, the waning gibbous moon rises in the east-northeast within two hours after sunset. Using binoculars, look for the reddish-orange star Aldebaran, eye of Taurus the Bull, close to the moon’s upper right. That night, the moon will gradually creep eastward against the background stars, away from Aldebaran. By an hour before sunrise on Monday, Nov. 6, the moon and star will be in the western sky, with the moon 6 degrees above the star.

Follow the moon daily an hour before sunup. On Nov. 8 and 9, watch it leap over the line connecting the Twins (Pollux-Castor) to Procyon. On Nov. 11, it stops just short of Regulus, heart of Leo. That morning, binoculars will show Regulus just east of the fat crescent moon. As seen from Palm Springs through a telescope that day, the leading bright edge of the moon covers the star at 8:55 a.m., and the moon’s trailing dark edge, invisible in daylight, uncovers it at 10:01 a.m.

By Nov. 11, you’ll want to look low in the east-southeast 40 to 60 minutes before sunrise each morning for a week, to follow the progress of the Venus-Jupiter pair. That morning, Jupiter appears 1.9 degrees to the lower left of Venus. On Sunday, Nov. 12, Jupiter appears just 0.9 degrees directly below Venus. Their closest pairing occurs on Monday, Nov. 13, with Jupiter now only one-third of a degree to the right of Venus and slightly higher. Jupiter is getting higher each day, Venus lower.

On Tuesday, Nov. 14, Jupiter appears 1.3 degrees to Venus’ upper right. By that morning, you can find faint Mars 6-7 degrees below the moon. On Nov. 15, find the crescent moon within 7 degrees to the lower left of reddish Mars and within 7 degrees to the upper left of blue-white Spica, forming a beautiful triangle with them. Some 17-19 degrees to the moon’s lower left, find the Venus-Jupiter pair still within 2.3 degrees apart. On Thursday, Nov. 16, in possibly the prettiest scene, Jupiter and Venus are 3.3 degrees apart, within 6 degrees to the lower right and 9 degrees below the moon. On Friday, Nov. 17, the moon’s final morning, look about 40 minutes before sunrise to spot the very thin old crescent within 5 degrees to the lower left of Venus. Jupiter will be 4.4 degrees to Venus’ upper right. Since the new moon occurs the next day, Nov. 18, at 3:42 a.m., a sighting of the moon on the morning of Friday, Nov. 17 will be about 22 hours before new.

Start looking for the young moon in the early evening on Sunday, Nov. 19. About 40 minutes after sunset, find the thin crescent very low in the west-southwest, with Mercury about 8 degrees to its left and a little lower. Saturn will be 12 degrees to the moon’s upper left and 8 degrees to the upper left of Mercury. The moon’s age will be nearly 38 hours after new. On the following evening, Nov. 20, seeing the moon should be very easy, as it sets in a dark sky nearly two hours after sunset. You still need to look early in twilight to catch Mercury, 8 degrees below the moon. Saturn will be 2 degrees to the moon’s lower left.

On the night of Nov. 21, Earth passes between the sun and the Pleiades (Seven Sisters) star cluster. Within an hour after sunset that evening, face east-northeast—opposite to the sun’s direction below the west-southwest horizon—and watch the Pleiades emerge and ascend in the deepening twilight. The scene is well described in lines by Alfred Lord Tennyson.

To celebrate the occasion of the Venus-Jupiter pairing, members of the Astronomical Society of the Desert are offering sky watches on Monday, Nov. 13, and the next four mornings, as the crescent moon passes through the gathering of three planets and a star, and the Venus-Jupiter pair grows wider each day. The sessions will be held from 5:15 until 5:45 a.m., on the pedestrian bridge crossing over Tahquitz Creek, at Camino Real between North and South Riverside drives, three blocks north of Cahuilla Elementary School. The session is dependent on sky conditions. If the sky is clear, we’ll be there, with telescopes and binoculars.

The website of the Astronomical Society of the Desert has a listing of our evening star parties at two locations. The primary, more accessible location is at the Visitor Center (VC) of the Santa Rosa and San Jacinto Mountains National Monument (on Highway 74, within four miles south of Highway 111 in Palm Desert). Sessions are scheduled there on Saturdays, Nov. 25 and Dec. 23, from 5 to 8 p.m. Sawmill Trailhead (SMT), our high-altitude site (elevation 4,000 feet—wear warm clothes), will have star parties starting at dusk on Saturdays, Nov. 11 and Dec. 9.

This year’s Night Sky Festival at Joshua Tree National Park will be held Nov. 10-12. For details, visit www.nps.gov/jotr/planyourvisit/night-sky-festival.htm. Also, check out the Sky’s the Limit Observatory and Nature Center in Twentynine Palms, at skysthelimit29.org.

Wishing you clear skies!

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing sky watching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

Jupiter is now the most prominent “star” in the evening sky, and Venus, even brighter and near peak brilliance, rules predawn. By May’s end, Saturn rises at a convenient evening hour, allowing both giant planets to be viewed well in the early evening. The moon always appears as a crescent in its monthly encounters with Venus, but is full whenever it appears near Jupiter or Saturn in the eastern evening sky opposite the sun.

The young crescent moon at dusk on May 26 marks the beginning of Ramadan, and appears to the lower left of faint, departing Mars.

May evenings: A huge conclave of seven stars of first magnitude or brighter in the western sky begins its annual departure in early May. The collection consists of the six stars of the Winter Hexagon, with Betelgeuse inside. The entire Hex is still visible at the start of May, but sky watchers must look sharply for Rigel, about to set in bright twilight a little south of due west. On each successive evening, the stars’ setting times occur nearly 4 minutes earlier, ever closer to the time of sunset. During May, in order of disappearance, Rigel, Aldebaran, Sirius and Betelgeuse sink into the bright western twilight glow, as shown on our evening twilight chart for May. By Memorial Day, all that remains of the Hexagon is its upper edge, forming aMemorial Arch: Procyon low in the west, Pollux (and slightly fainter Castor, not plotted, 4.5 degrees to its right) atop the arch, and Capella, low in the northwest.

Venus left our evening sky in late March, leaving Jupiter to reign as the brightest “star” in the evening sky. Our evening twilight chart shows Jupiter ascending from the southeast toward the south during May. Last month, our planet Earth passed between the sun and Jupiter, and that planet appeared 180 degrees away from the sun in our sky on April 7, at opposition and visible all night, from dusk until dawn. Go outside on the evening of May 20, and visualize Earth’s motion of 18.6 miles per second around the sun and directly away from the star Regulus, while the Pleiades star cluster is hidden beyond the sun. Ten days later, in a grand annual syzygy on May 30, three stars and our planet lie in a nearly straight line in space, in the order of Aldebaran-sun-Earth-Antares. Aldebaran, eye of Taurus, is then invisible on the far side of the sun, while Antares, heart of the Scorpion, is at opposition to the sun and visible nearly all night. On our twilight chart, Antares is shown rising into view in the southeast late in May.

Other prominent stars on May evenings include bright golden Arcturus, high in the east to south; Spica, near Jupiter; Regulus, just south of a line connecting Jupiter to Pollux; and bright blue-white Vega, rising in the northeast, with Deneb following to its lower left.

The Abrams Planetarium Sky Calendar is available at www.abramsplanetarium.org/skycalendar. The May issue may be reprinted and distributed at no charge. The calendar includes illustrations of the moon passing by planets and bright stars, and the sky map depicts more stars and constellations than our twilight charts show.

In May’s morning twilight, we find brilliant Venus low in the east. Telescopes reveal Venus still in crescent phase in May, filling out to being half-lit by early June, but shrinking in size as the planet speeds away from Earth. Use binoculars to spot Mercury to the lower left of Venus starting in the second week. Follow Arcturus, sinking in the west to west-northwest; the Summer Triangle, passing overhead; and Saturn, with twinkling Antares to its lower right, sinking in the southwest. Fomalhaut is rising in the southeast.

The moon near planets and stars in May: Check illustrations on the May Sky Calendar to remind yourself to catch the moon near Jupiter and Spica on the evening of May 7. After the moon passes full on May 10, switch your viewing time to before dawn to see the moon pass widely north of Antares on May 12, and skip from west of Saturn to east of it on the next two mornings. The moon is near last-quarter phase (half full) on the mornings of May 18 and 19. Glance up to see the moon in the daytime before the morning start of your workday, and note how the side toward the sun is illuminated. If you hold a ball up at arm’s length to appear near the moon, you’ll notice the ball is illuminated in the same way.

In a spectacular conjunction before dawn on Monday, May 22, the waning crescent moon passes closely south of Venus. Seize the occasion to spot Venus in the daytime. Before dawn on May 23, the moon is to the lower left of Venus and to the upper right of Mercury. On May 24, use binoculars about 30 minutes before sunrise to try to see the rising of the old moon, just 3 percent full, some 8 degrees to the lower left of Mercury, and within 32 hours before new. It’ll be very low in bright twilight; you’ll need perfect skies and a low horizon to see it.

New moon occurs on May 25 at 12:44 p.m., only five hours after perigee, when the moon is closest to Earth. As a result, the moon ascends quickly from one evening to the next at the same stage of twilight. On May 26, 30 minutes after sunset, the first crescent moon, marking the start of the fasting month of Ramadan, should be easily seen if skies are clear. It will appear 3 percent full and about 7 degrees up in the west-northwest for sky watchers in the Coachella Valley. (You’ll need to go to a place where our high mountains won’t block the view.) As twilight deepens, binoculars may show faint Mars about 6 degrees to the moon’s upper right. In the rest of May, watch the waxing moon pass widely south of the Gemini twins Pollux and Castor on May 28, and leapfrog past Regulus on May 30 to 31. On the latter night, the moon is approaching first-quarter phase and is nearly half full.

The Astronomical Society of the Desert will host the last of the season’s monthly public star parties at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument, on Saturday, May 20, from 8 to 10 p.m. The Visitor Center is on Highway 74, within four miles south of Highway 111 in Palm Desert. After May 20, the next star party at the same location will be on Oct. 28. Check www.astrorx.org for listings. Star parties at the Sawmill Trailhead, our high-altitude site (4,000 feet—wear warm clothes), start at dusk on Saturday. June 24, July 22, Aug. 19, Sept. 23, and Oct. 14. Follow links to maps and directions.

Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time. Sessions might be scheduled at dusk or dawn to view planets—Jupiter with its moons, or Saturn with its rings—or a young or old crescent moon. In May 2017, special sessions will be held in daytime and at dawn to observe Venus at its brightest, in crescent phase. A session might include a bright flyover of the International Space Station.

It’s not too early to make plans for a very special event on Monday, Aug. 21, if you want to travel to see the event at its best: It’s a solar eclipse, visible throughout North America, and visible as a total solar eclipse within a narrow track across the U.S., tracking coast to coast from Oregon to South Carolina. Get to the path of totality if you can! Whether you do so, or you stay here at home to see the partial eclipse, the following web resources should help you prepare yourself and your family and friends for the event, and observe it safely.

www.eclipsewise.com/solar/SEnews/TSE2017/TSE2017.html

eclipse.aas.org

eclipse2017.nasa.gov

www.skyandtelescope.com/total-solar-eclipse-august-2017

www.astrosociety.org/education/2017-solar-eclipse-information-resources

static.nsta.org/extras/solarscience/SolarScienceInsert.pdf

eclipsophile.com/total-solar-eclipses/total-solar-eclipse-2017-august-21

aa.usno.navy.mil/data/docs/Eclipse2017.php

www.astronomy.com/great-american-eclipse-2017

www.greatamericaneclipse.com

Robert C. Victor, formerly a staff astronomer at Abrams Planetarium at Michigan State University, is now retired and enjoys providing sky watching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University, and remains active in research and public outreach in astronomy.

Published in Astronomy

This month’s selection of happenings includes the last evening and first morning appearances of Venus; the year’s most favorable apparition of Mercury; early evening moonrises; simultaneous views of planets low above opposite horizons (Mars-Jupiter and Mercury-Jupiter in the evening, with Venus-Jupiter in the morning); and a bright, far southern star, Canopus, reaching its high point very low over our southern mountains.

Venus is still very prominent in the evening sky as this month opens, setting in a dark sky 2 1/2 hours after sunset on March 1. By March 17, Venus sets just one hour after sunset, and by March 21, Venus drops below the horizon barely half an hour after sunset. By that date, Venus is already rising ahead of the sun, and it’s possible to observe it at both dusk and dawn for a few days. Through a telescope or even 7-power binoculars, the planet displays a crescent—best observed in daytime, or in bright twilight.

Our evening sky chart plots daily positions of the brightest objects in the sky at mid-twilight, when the sun is 9 degrees below the horizon, about 40 minutes after sunset. As March begins, the most prominent objects, in order of brightness, are Venus in the west; Sirius in the south-southeast; Canopus very low, just east of due south; Capella just north of overhead; and Rigel in the south. As March runs its course, Venus descends the near side of her orbit and drops below the western horizon, but not before Mercury climbs into view on the far side of his orbit. For a few evenings, both planets are visible. They appear closest to each other on March 18, with emerging Mercury passing 8.5 degrees south (to the lower left) of departing Venus. In the eastern sky just before month’s end, bright Jupiter rises a few degrees south of due east, while golden Arcturus rises in the east-northeast.

Sirius and Capella mark extreme south and north vertices of the huge “Winter Hexagon,” with Betelgeuse and Orion’s belt inside. The belt points the way to Sirius, and in the opposite direction, to Aldebaran. Preceding the Hex across the sky in March is faint Mars, itself preceded by Venus or Mercury, or both planets for a few days starting in midmonth. The trailing Pollux-Procyon side of the Hex reaches due south at mid-twilight at the end of March. Following them is Regulus, heart of Leo, Still farther east, we find Jupiter and Arcturus rising into view later in the evening, or by mid-twilight at month’s end.

In morning twilight: Jupiter, in the southwest to west-southwest as dawn brightens, ranks first in brightness, until Venus emerges north of east late in the month. Before the sky brightens too much, note Spica 4-6 degrees to the lower left of Jupiter. The most prominent stars are golden Arcturus high in the west-southwest to west, far to the upper right of the Jupiter-Spica duo, and blue-white Vega, very high in the northeast. Next in brightness is steady yellow Saturn, in the south-southeast to south. Look also for Altair and Deneb, completing the Summer Triangle with Vega. Find twinkling reddish Antares to the west and south of Saturn.

On March 1, the 15 percent crescent moon appears well to the upper left of Venus and a few degrees left of Mars. The moon climbs much higher each evening, and on Saturday, March 4, the nearly half-lit moon will occult, or cover, the bright star Aldebaran, with a sudden disappearance behind the moon’s leading dark edge slated for 7:12 p.m., and reappearance for 8:30 p.m. Binoculars and maybe even the unaided eye will suffice for the first event, but a telescope will be required to catch the star’s reappearance at the moon’s bright edge.

The moon continues to march eastward, passing between Procyon and the Gemini twins, Pollux and Castor, by March 7, and getting past Regulus, heart of Leo, by the evening of March 10. On Saturday evening, March 11, the almost-full moon rises at 5:14 p.m., still before sunset, which occurs at 5:51 p.m. Remember to set your clocks one hour ahead, and you won’t be surprised by Sunday’s later sunset at 6:52 p.m., and moonrise (just past full) at 7:13 p.m. After moonrise on Wednesday, March 15, look for bright Jupiter nearby, with Spica just a few degrees to the lower right.

With daylight saving time shifting our sunrises an hour later, predawn sky-watching becomes more attractive. Look an hour before sunrise on March 14 and 15 for the waning gibbous moon with Jupiter nearby, in the southwest to west-southwest. Spica is to Jupiter’s lower left. On the weekend of March 18-19, find reddish twinkling Antares near the moon in the southern sky, with brighter, steady Saturn to their left. On Monday morning, March 20, the moon, nearly at last quarter phase and just over half full, will appear closely to the upper left of Saturn. A telescope reveals the planet’s amazing rings, tipped nearly 27 degrees from edge-on this year, the greatest angle possible.

See Venus at both dawn and dusk for a few days! Around March 20, start trying to observe Venus rising before the sun, even though it’s still also visible in the evening, setting after sunset. Binoculars will reveal Venus as a large, thin crescent, as little as 1 percent illuminated on March 23-26.

On March 25, at 6:22 a.m., about 20 minutes before sunrise, find the thin (8 percent) old crescent moon 12 degrees up in the east-southeast. Locate Venus 32 degrees farther left and 10 degrees lower, or 10 degrees north of east and only 2 degrees up. This is the day Venus appears at inferior conjunction, an unusually wide 8.3 degrees north of the sun and 1 percent illuminated. On Friday, March 26, at 6:21 a.m., find the 3 percent crescent moon 12 degrees south of east and 4 degrees up.

The young lunar crescent first appears in the evening on Tuesday, March 28, around 7:29 p.m., nearly due west, just 5 degrees up and a few degrees to the lower left of bright Mercury. The next evening, March 29, look for the 5 percent crescent moon 40 minutes after sunset, 15 degrees up and to the upper left of Mercury. As twilight deepens, look for dim Mars about 10 degrees above the moon and a little right. By Thursday evening, March 30, the moon will climb to the upper left of Mars. Watch for Jupiter rising 7 degrees south of east just more than half an hour after sunset. Can you observe the three evening planets, Mercury, Mars and Jupiter, simultaneously?

The Astronomical Society of the Desert will host the next in our series of monthly star parties on Saturday, March 4, from 6 to 9 p.m., and on Saturday, April 1, from 7 to 10 p.m. They are held at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument, on Highway 74, within 4 miles south of Highway 111 in Palm Desert. Check www.astrorx.org. The next high-altitude star party at Sawmill Trailhead (at 4,000 feet—wear warm clothes!) will be held Saturday, March 25. Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

Evening twilight: Venus rules! You won’t fail to notice this brilliant light in the southwest at dusk. Look for Mars to its upper left, and, for the first two or three weeks of December, Mercury to Venus’ lower right, provided you have an unobstructed view. The moon passes through this section of sky Nov. 30-Dec. 5.

The Summer Triangle of Vega, Altair, and Deneb is not far west of overhead in twilight in early December, and drifts westward as this month progresses. Blue-white Vega is next in brightness after Venus among objects visible in December’s evening twilight. Yellow Capella in the northeast is almost as bright. To Capella’s lower right, red-orange in color, is Aldebaran, eye of Taurus, the Bull, ascending in the east-northeast to east. Later in the month, Orion’s brightest stars, reddish Betelgeuse and bluish Rigel, rise almost together not far from due east. In December at dusk, look for Fomalhaut, mouth of the Southern Fish, crossing the southern sky about 25 degrees above the horizon.

Later in the evening, Orion is higher, and now the “Dog stars,” Sirius and Procyon, following the Hunter across the sky, have risen into view. Notice that Orion’s belt points downward to Sirius, the brightest star, and upward toward Aldebaran and the Hyades star cluster, and beyond to the Pleiades, or Seven Sisters, star cluster. Both star clusters are spectacular fields for binoculars!

Morning twilight: Now Orion and company are descending in the western sky, with some stars already out of view. Jupiter is the dominant “morning star” in the southeast to south, with first-magnitude Spica in Virgo not far below. After Sirius departs in the southwest, the brightest actual star remaining is golden-orange Arcturus in the east. Vega, reincarnated in the northeast, and Capella, sinking in the northwest, are almost as bright. Regulus, heart of Leo, the Lion, is high in the southern sky, going west as weeks pass. Before month’s end, watch for Antares and Saturn emerging out of the sun’s glare in the southeast.

Moon and planets: Watch the waxing crescent moon pass three planets Nov. 30-Dec. 5. The moon will appear to the upper right of Mercury on Nov. 30; above Mercury and to the lower right of Venus on Dec. 1; near Venus on Dec. 2 and 3; and near Mars on Dec. 4 and 5. Mercury stays 24 degrees to the lower right of Venus Dec. 2-12, then falls away and fades. Venus-Mars are 23 degrees apart on Dec. 2, narrowing to 12 degrees on Dec. 31.

See Venus in daytime: On Tuesday, Dec. 6, Venus follows the sun’s path. Place the sun just above an object such as a treetop or building around midday or in the afternoon. Return to the same observing location three hours and 12 minutes later, and Venus will appear in the same spot! On that date, telescopes show Venus two-thirds full. Watch for big changes in coming months, as Venus draws closer to Earth and becomes backlighted by the sun.

Aldebaran, eye of Taurus, is occulted by the moon on evening of Monday, Dec. 12. Since the moon is almost full, a telescope is needed to observe the star’s disappearance and reappearance. From the Coachella Valley, the leading dark edge of the moon covers the star shortly after 7:02 p.m., and the star reappears at the moon’s bright edge at 8:09 p.m.

The full moon on Tuesday, Dec. 13, rises within a quarter-hour after sunset. The peak of the Geminid meteor shower later that night will be greatly spoiled by moonlight; only the brighter meteors will be seen. Meteors might appear anywhere in the sky. To check if a meteor is a member of the Geminid shower, extend its track backward beyond the point where you saw the meteor light up. The track should extend back toward the radiant of the shower, near the star Castor in Gemini. Castor is very low in the northeast two hours after sunset, and nearly overhead shortly before 2 a.m.

After passing full, the waning gibbous moon, in the morning sky, passes the Twin stars Pollux and Castor in Gemini on Dec. 16; and Regulus, heart of Leo, on Dec. 18.

Winter begins on Dec. 21 at 2:44 a.m. On the next morning, Dec. 22, the moon appears as a thick crescent near Jupiter and Spica, and then several days later on Dec. 26 and 27 as a much thinner crescent near Antares and Saturn.

On Tuesday, Dec. 27, as morning twilight brightens, bright Jupiter is in the south-southeast, approaching its high point in the south. Look low in the southeast to east-southeast for the last easy old crescent moon, with Saturn 4 degrees below. In late December, Jupiter and Saturn are 60 degrees apart.

On Wednesday, Dec. 28, the old moon is hard to see, but it’s worth trying for rare opposing crescent moons on consecutive days: Dec. 28 at dawn, and Dec. 29 at dusk. On Dec. 28, using binoculars 20 to 30 minutes before sunrise, try for the crescent moon rising 9-10 degrees to the lower left of Saturn. The new moon occurs later that day, at 10:53 p.m. At early dusk on Thursday, Dec. 29, about 20 minutes after sunset, note Venus well up in the southwest. Using binoculars, try for the young crescent moon within 39 degrees to the lower right of Venus. To see the old moon on Dec. 28 and the young moon on Dec. 29, you’ll need very clear skies, unobstructed views, and binoculars or a telescope. Good luck!

On New Year’s Eve, you can conveniently find the most distant planet of our solar system. Get your telescope out at nightfall (about 90 minutes after sunset), and point it at Mars. Neptune, very faint at eighth magnitude, will appear very closely east of Mars, following the red planet through the telescopic field. As the evening progresses, Mars will appear to close in on the dim, more-distant planet.

Star parties: They provide wonderful opportunities to join with other folks to get great views of astronomical objects through a variety of binoculars and telescopes. The Whitewater Preserve will be hosting a star party on Saturday, Dec. 10, weather permitting, from dusk until 9 p.m. Reservations are requested; please call 760-325-7222.

The Astronomical Society of the Desert will host the next of our series of monthly star parties on Saturday, Dec. 17, from 5 to 8 p.m. They are held at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument, on Highway 74, within 4 miles south of Highway 111 in Palm Desert. Check www.astrorx.org for listings of our high altitude star parties at Sawmill Trailhead starting at dusk. The next one (at 4,000 feet—wear warm clothes!) will be held on Saturday, Dec. 3. Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

Brilliant Venus (magnitude -4.0) and fainter Saturn ( +0.5) are 4.5 degrees apart in the southwest at dusk on Nov. 1, but Venus speeds away while Saturn sinks into the solar glare, widening the gap between them to nearly 15 degrees by Nov. 11, and to 22 degrees by Nov. 18. Use binoculars to watch Venus pass background stars in Ophiuchus and Sagittarius on Nov. 4, 16, 17, and 22. Venus sets farthest south Nov. 14. By month’s end, Venus brightens to magnitude -4.2 and is noticeably higher than it was at the start of November. A telescope shows Venus in gibbous phase, 70 percent full at month’s end. Wonderful changes will happen in coming months, before Venus departs from the evening sky in late March.

Mercury (magnitude -0.5) passes 3.5 degrees south (to the lower left) of Saturn on Nov. 23, but they’ll both be very low in the twilight glow, with Mercury brighter. Using binoculars, look 27 degrees to the lower right of Venus. Replacing Saturn, Mercury is 25 degrees to the lower right of Venus on Nov. 30, and will hold 24 degrees to the lower right of Venus Dec. 2-12.

Look for dim Mars (magnitude +0. 4 to +0.6) in the south to south-southwest, to the upper left of Venus, by 37 degrees on Nov. 1; 30 degrees on Nov. 16; and 24 degrees on Nov. 30. Watch Mars pass third- and fourth-magnitude stars in Capricornus, the sea-goat, on Nov. 14 and 27, and on Dec. 10.

In the morning sky in the east-southeast to southeast, find bright Jupiter, magnitude -1.7 to -1.8. As the sun withdraws east of Jupiter this month because of Earth’s faster revolution around the sun, the giant planet ascends higher in predawn. Note the first-magnitude star Spica in Virgo, 13 degrees to 8 degrees below bright Jupiter.

The moon, as a waxing crescent in evening sky, can be seen in a pretty gathering with Venus and Saturn on Nov. 2; near Mars on Nov. 5 and 6; near Mercury on Nov. 30; near Venus on Dec. 2 and 3; and near Mars on Dec. 4 and 5. In the mornings, follow the waning moon, near Aldebaran, eye of Taurus, on Nov. 15; near Pollux, brighter of the Gemini twins, on Nov. 18; near Regulus, heart of Leo, on Nov. 21; near Jupiter on Nov. 24; and near Spica and Jupiter on Nov. 25.

The full moon, on Monday, Nov. 14, at 5:52 a.m., follows the moon’s perigee (closest approach to Earth) by only 2.5 hours. The resulting “Supermoon” is the closest until Nov. 25, 2034. (Get ready for the inevitable hype in the news media!) The next “Supermoon” closer than that one will occur on Dec. 6, 2052—the best of the 21st century. The moon this month will be closest for observers in the Coachella Valley on the night of Sunday, Nov. 13, just a few minutes after the moon reaches its highest point in the south, at 11:20 p.m., and, contrary to appearances, not when the moon is rising on Sunday around 4:33 p.m. or setting Monday morning around 6:11 a.m. (The moon just seems larger at rising or setting than when it is high in the sky. It’s called the “moon illusion.”) Also, this is not the brightest full moon of this year. That’s because this month’s full moon passes widely south of Earth’s shadow, and does not reflect as much light toward us as it would if the moon narrowly missed the shadow. The sharp brightening of the moon or an asteroid when it appears almost exactly 180 degrees from the sun is sometimes called “the opposition effect,” or “opposition surge.”

Star parties provide wonderful opportunities to join with other folks who love to share their interest in observing the sky, and to get great views of astronomical objects through a variety of binoculars and telescopes. The first two events, happening this weekend, are annual gatherings not far from the Coachella Valley: The 2016 Nightfall Star Party takes in Borrego Springs Oct. 27-30, while the 2016 Joshua Tree National Park Night Sky Festival is Oct. 28-30.

Local star parties (in and near the Coachella Valley): The Astronomical Society of the Desert will host the next of our series of monthly star parties on Saturday, Nov. 5, from 6 to 9 p.m., and on Saturday, Dec. 17, from 5 to 8 p.m. They are held at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument, on Highway 74, within four miles south of Highway 111 in Palm Desert. Check the society’s website at www.astrorx.org for listings of our regular star parties at the Visitor Center, and our high altitude star parties at Sawmill Trailhead starting at dusk. The next high-altitude star parties (at 4,000 feet—wear warm clothes!) will be held on Saturday, Nov. 19, and on Saturday, Dec. 3. Follow links to maps and directions to both star party sites, and for dates and locations of lecture meetings. Also, check the link to our “Impromptu Star Parties,” which could be announced on short notice at any time.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

On Thursday morning, Sept. 29, a beautiful sight will reward early risers who go out to enjoy the brightening dawn 45 minutes to an hour before sunrise: About 5:45 a.m. in the Coachella Valley that morning, very low, almost directly east, a slender, crescent old moon will be suspended just 2 degrees below Mercury.

Other sights in the morning sky through October include Sirius, the brightest star, well up in the south-southeast, and the rest of the Winter Hexagon’s stars—in clockwise order, Procyon, Pollux (and Castor, not shown), Capella, Aldebaran and Rigel, with Betelgeuse inside. Other bright stars include Canopus, very low in the south, the second brightest star (easier to see later in the month, when it reaches its high point, due south, earlier in a darker sky), and Regulus, heart of Leo, the Lion, in the east.

The old moon of Sept. 29 is followed by the new moon on Fri. Sept. 30 at 5:11 p.m., invisible as it passes close to the sun. The next chance to see the moon is on the evening of Saturday, Oct. 1, only about 20 to 30 minutes after sunset. With all the mountains around us, you must choose your vantage point carefully, because about 20 minutes after sunset in the Coachella Valley, or about 6:50 p.m., the very slender crescent will be only 3 to 4 degrees up. Binoculars will help. Look for the hairline crescent 9 degrees south of due west and 20 degrees to the lower right of Venus. This crescent moon is special, because its sighting marks the beginning of the first month of the new year of the Islamic calendar.

The moon will be much easier to spot as it thickens, appears higher, and sets more than half an hour later nightly. On Sunday, Oct. 2, the moon will be 10 degrees to the lower right of Venus. On Monday, Oct. 3, the moon will pass within 5 degrees to the upper right of Venus, and on Tuesday, the moon will appear 13 degrees to the upper left of Venus. On Oct. 5, the moon passes within 5 degrees to the upper right of Saturn, and on Friday the 7th, the moon will be 7 degrees to the upper right of Mars.

Besides these three planets, other prominent objects at dusk include golden Arcturus sinking in the west, and blue-white Vega northwest of overhead, with Deneb and Altair, completing the Summer Triangle.

The full moon of Saturday, Oct. 15, rises just north of due east a few minutes after sunset that evening. The waning moon rises later each night, shifting farther north along the horizon nightly through Oct. 20.

In the Coachella Valley at 9 p.m. on the evening of Tuesday, Oct 18, binoculars will show a bright star within one degree to the lower left of the moon, just risen in the east-northeast. By 10:19 p.m., the sunlit edge of the moon will cover first-magnitude Aldebaran, eye of Taurus, the Bull. Aldebaran remains hidden by the moon until 10:35 p.m., when the star reappears along the northern part of the moon’s dark edge. Even though this is the brightest star the moon can occult (cover), a telescope will be needed to observe the star disappear and reappear, since the moon is very bright—only three days past full.

Watch the planets move! In the evening sky in October, Venus goes east 1.2 degrees per day against background stars, while Mars goes east about 0.7 degrees daily. Follow their progress easily from one night to next for several evenings around dates when planet passes a star. Track Venus for a few evenings around following dates when it passes close to a background star: Oct. 5, when Venus passes 0.8 degrees to the lower left of third-magnitude Alpha in Libra, also known as Zubenelgenubi, the southern claw of an early, larger version of the Scorpion; Oct. 20, when Venus passes within 1 degrees above second-magnitude Delta Scorpii, the middle of the three stars in the head of the Scorpion; Oct. 26, when Venus passes 3.1 degrees north (to the upper right) of first-magnitude Antares; and Oct. 29, when Venus passes 3.0 degrees south (to the lower left) of Saturn.

Watch Mars on Oct. 6, as it passes 0.2 degrees below third-magnitude Lambda Sagittarii, marking the top of the Teapot. This star is also known as Kaus Borealis, northern star of the Archer’s bow. On Oct. 15, Mars passes within 1.3 degrees north (to the upper right) of second-magnitude Nunki, or Sigma in Sagittarius, brightest star in handle of the Teapot.

Saturn, the only other bright evening planet, moves only 2.7 degrees east during Oct. 1-31, averaging less than 0.1 degrees per day.

In the mornings: Just before the start of twilight Sept. 29-Oct. 12 and Oct. 29-Nov. 11, from a very dark place, try to see the zodiacal light—from sunlight reflected off comet and asteroid dust in the plane of the solar system. Look for a huge pyramid of faint light extending upward from the eastern horizon toward the star Regulus in Leo.

Low in the east during morning twilight in October, bright, emerging Jupiter replaces Mercury. Using binoculars about 40 minutes before sunrise, see both planets for a few days around Oct. 11. The best mornings are Oct. 10-12: The planets are 1.5 degrees apart on Oct. 10, with Jupiter to the lower right of Mercury. They appear closest, 0.8 degrees apart, on Oct. 11, with Jupiter to the south (right) of Mercury. They’re 1.9 degrees apart on Wednesday, Oct. 12, with Jupiter to the upper right.

On Friday, Oct. 21, in the predawn darkness hours, watch for the peak of the Orionid meteor shower, consisting of particles from Halley’s Comet.

On Friday, Oct. 28, a waning crescent moon, two days before new, will appear 2-3 degrees to the lower left of Jupiter in morning twilight. On Saturday morning, Oct. 29, the last old crescent will appear 14 degrees to the lower left of Jupiter. Binoculars will help you pick out emerging Spica, just five degrees to the lower right of the delicate crescent. The new moon occurs on Sunday, Oct. 30, at 10:38 a.m.

On Monday evening, Oct. 31, 40 minutes after sunset, the young crescent moon will be 3 degrees up in the west-southwest, 24 degrees to the lower right of Venus.

The Astronomical Society of the Desert will host the next of our popular series of monthly star parties on Saturday, Oct. 8, from 7 to 10 p.m. They are held at the Visitor Center of the Santa Rosa and San Jacinto Mountains National Monument, on Highway 74, within 4 miles south of Highway 111 in Palm Desert. Check www.astrorx.org for listings of our high altitude star parties at Sawmill Trailhead starting at dusk. The next one will be held on Saturday, Oct. 22. Visit the website for maps and directions to both star party sites, and for dates and locations of lecture meetings. Also, follow the link to our “Impromptu Star Parties, which could be announced on short notice at any time.

Also, don’t miss the 2016 Joshua Tree National Park Night Sky Festival on Oct. 28-30 and the 2016 Nightfall Star Party in Borrego Springs Oct. 27-30.

The Wildlands Conservancy’s Whitewater Preserve at 760-325-7222 and the Pioneertown Mountains Preserve at 760-369-7105 occasionally host star parties. The next one at Pioneertown Preserve is set for Oct. 8. Reservations required; call the appropriate preserve.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs. Robert D. Miller did graduate work in planetarium science and later astronomy and computer science at Michigan State University and remains active in research and public outreach in astronomy.

Published in Astronomy

All three bright outer planets remain prominent in the evening sky this July.

At dusk, find bright Jupiter in the west-southwest to west, apricot-colored Mars in the southern sky, and Saturn not far to the left of Mars. Venus passed behind the sun in early June, but by mid-July, it emerges into our early evening sky very low in the west-northwest bright twilight glow, 20 minutes after sunset. Look from a place with a view unobstructed by mountains, and use binoculars to help you spot Venus in bright twilight in its first weeks. Binoculars will reveal Mercury near Venus from mid-July until late August. That’ll bring the total to all five bright planets visible simultaneously!

Attend a star party hosted by one of the local astronomy clubs for telescopic views of Jupiter’s cloud belts and four largest moons; Saturn’s spectacular rings and largest moon Titan; the south polar cap and other markings on Mars; and many deep-sky wonders beyond the solar system, in our Milky Way galaxy, and beyond!

Our chart depicting the sky at evening mid-twilight in July follows positions of naked-eye planets and stars of first magnitude or brighter in the sky when the sun is 9 degrees below the horizon, roughly 45 minutes after sunset. Planets are plotted as dots, one for each day, with labels for dates at weekly intervals.

On this map, you’ll find bright Jupiter starting well up, a little south of due west, at dusk in early July 2016, with faint Regulus, heart of Leo, preceding it as they sink toward the western horizon over the course of the month.

Mars starts a little east of due south at dusk in early July. Note the shape of the triangle it forms with Saturn to its left, and the red twinkling star Antares, heart of the Scorpion, below Saturn. The triangle will shrink in coming weeks.

The Summer Triangle of Vega, Deneb and Altair ascends the eastern sky at dusk in July. Its brightest star, blue-white Vega, marks the top of the triangle. Two other bright stars, golden Arcturus and blue-white Spica, are high in the southwest quarter of the sky.

Mercury and Venus first appear on our evening mid-twilight chart in late July, but if you observe earlier in twilight, some 20 to 30 minutes after sunset, and use binoculars, you can catch their closest pairing very low in the west-northwest on July 16, as Mercury (magnitude -1.0) passes just 0.5 degrees north (to the upper right) of Venus (-3.9). (You’ll need a viewing site where mountains don’t block your view!) On the previous evening, July 15, you can spot Mercury 0.8 degrees to the right of Venus, with the two setting at about the same time. On following evenings, Mercury shifts to the upper right of Venus, and next above it, and then toward Venus’ upper left, with their separation widening. During July 16-Aug. 19, Mercury appears higher than Venus, and sets as much as 18 minutes after Venus during from July 30 to Aug. 4.

Follow the moon: Its day-to-day change in position against the stars, averaging 13 degrees per day, is much more noticeable than that of the planets. Watch the moon change from a thin crescent to just past full July 5-20, while passing the planets and the bright stars plotted on our evening twilight charts. Watch for these events:

Tuesday, July 5: See the first crescent moon, age 40.5 hours after new, half an hour after sunset. Binoculars give fine views of this thin moon very low in the west-northwest, provided mountains don’t obstruct your view. Sighting of this crescent marks the start of a new month, ending the fasting month of Ramadan.

Thursday, July 7: Regulus, heart of Leo, appears closely north of the crescent moon.

July 8 and 9: Jupiter is closely to the upper left of the moon on Friday, then not-so-closely to the lower right of the moon on Saturday.

Monday, July 11: The moon is near first quarter phase. Look for the star Spica, the spike of wheat in hand of Virgo, a few degrees north of the moon.

July 13 and 14: Mars is widely to the lower left of the gibbous moon on Wednesday, and not-so-widely to the lower right of the moon on Thursday.

Friday, July 15: Saturn is closely below the moon. Note Antares, heart of Scorpius, the Scorpion, below Saturn.

Saturday, July 16: A close pairing of Mercury-Venus in bright twilight is described above.

Tuesday, July 19: The moon passes full phase shortly before 4 p.m., and rises in the east-southeast at 7:45 p.m., or 10 minutes before sunset in Palm Springs. Because of our surrounding mountains, you must wait several minutes until the moon’s disk begins to appear.

Watch for the moonrise on subsequent evenings: Wednesday, July 20, at 8:30 p.m.; Thursday, July 21, at 9:12 p.m.; Friday, July 22, at 9:52 p.m.; Saturday, July 23, at 10:31 p.m.; Sunday, July 24, at 11:10 p.m., nearly due east; and Monday, July 25, at 11:49 p.m. You’ll notice the moon rising farther north each night until night of July 30-31, when it will rise in the east-northeast at 3:31 a.m. on Sunday morning, July 31.

Early in July, before the moon gets bright, and again beginning around July 22 or 23—when the waning moon after full starts rising late in the evening—go to a dark location after nightfall and enjoy spectacular views of the summer Milky Way. Follow its path from the “W” of Cassiopeia low in the north-northeast, through the Summer Triangle along the Northern Cross, or neck of Cygnus, the Swan, then down toward the Teapot of Sagittarius to the left of Scorpius in the southern sky. Part of the Milky Way resembles a puff of steam rising out of the spout of the Teapot. From within the Summer Triangle and southward, look for the long Great Rift, where the river of the Milky Way is divided into two streams by clouds of obscuring interstellar dust in the foreground blocking the light of the stars beyond. A pair of binoculars will easily resolve the bright Cygnus Star Cloud (where we look into our own spiral arm, along the neck of the Swan) into multitudes of stars!

Telescopic views of planets: Jupiter’s dark equatorial cloud belts and up to four of the bright satellites discovered by Galileo offer a pleasing view for small telescopes.

Mars, still showing a fair-sized disk after its closest approach in late May, displays surface detail! This month, Mars’ southern hemisphere spring equinox will occur on July 4. Although the south pole of Mars is then on the Martian terminator (day-night boundary), that pole is now tipped 15 degrees out of Earth’s view—the surrounding south polar cap of frozen carbon dioxiode (or its overlying cloud cover) is near its maximum extent, reaching halfway from pole to equator, far enough to spill over the southern limb. So whenever you look at Mars early this summer, you’ll see a bright southern edge to Mars’ disk.

Enjoy Saturn’s rings this summer! They’re now tipped from edge-on by almost the greatest angle possible. Using as high of a magnification as your telescope and atmospheric conditions allow (I often use 200x with my 6-inch reflector), try for the Cassini Division dividing the outer A ring from the broader, brighter B ring. This narrow gap is nearly two-thirds of the way from the inner edge of B toward the outer edge of A. Look also for Titan, Saturn’s largest moon, taking 16 days to complete one circuit about the planet. Its nearly circular orbit is almost nine times as large as the outer edge of Saturn’s A ring, in nearly the same plane as the rings now tipped 26 degrees from edge-on, and so it appears as an ellipse.

Titan will appear farthest west of Saturn on July 3 and 19, and farthest east on July 11 and 27. We are seeing the north face of the rings and of Titan’s orbit, so we’ll see Titan at superior conjunction (the far side of Saturn) four days after it appears farthest to the west, and at inferior conjunction (near side of Saturn) passing south of the planet four days after greatest elongation east.

Venus, just emerged from the far side of the sun, appears tiny and full, and low in twilight. It will become much more interesting for telescopic viewing as it nears the end of its evening apparition.

Predawn sky: There are no morning planets visible to the unaided eye in July. (Uranus and Neptune require at least binoculars and detailed finder charts.) But cooler mornings make for more comfortable sky viewing. As dawn begins to brighten, we find the Summer Triangle well up in the western sky, getting lower as the month progresses. Fomalhaut, mouth of the Southern Fish, is in south to south-southwest, and Capella, the Mother Goat star, is ascending in the northeast. To Capella’s lower right, we find ruddy Aldebaran, eye of Taurus the Bull. Before the sky brightens, look above Aldebaran for the beautiful Pleiades star cluster (the Seven Sisters), a wonderful target for binoculars!

Late in July, the two brightest stars of Orion the Hunter rise into view: reddish Betelgeuse with blue-white Rigel to its right. Between them lies the Hunter’s belt of three stars in a nearly vertical line. Orion will rise two hours earlier as each month passes.

The Astronomical Society of the Desert hosts monthly star parties at Sawmill Trailhead (elevation 4,000 feet). For dates, with map and directions to the site, visit the Society’s website at www.astrorx.org.

Sky’s the Limit Observatory in Twentynine Palms offers star parties most Saturday evenings, except when the moon is close to full. For details, visit www.skysthelimit29.org.

Robert C. Victor was a staff astronomer at Abrams Planetarium at Michigan State University. He is now retired and enjoys providing skywatching opportunities for school children in and around Palm Springs. Robert D. Miller, who provided the twilight charts, did graduate work in planetarium science and later astronomy and computer science at Michigan State University. He remains active in research and public outreach in astronomy. Dr. Jeffrey L. Hunt, a retired planetarium director now living in the Chicago area, did the Venus map below. He has taught astronomy and sky watching to all ages. He studied astronomy education at Abrams Planetarium at Michigan State University. Jeff writes an astronomy blog at jeffreylhunt.wordpress.com and can be followed on Twitter at @jeff_hunt.

Published in Astronomy

Page 1 of 3