Last updateWed, 27 Sep 2017 1pm


31 May 2016
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Now that the Earth has overtaken all the bright outer planets (with the final one being Saturn, reaching opposition on June 2), we can conveniently follow them at dusk for several months: Jupiter until start of September, Saturn until Thanksgiving, and Mars until end of May 2017. Venus passes behind the sun on June 6, and by middle of July will emerge into our early evening sky very low in the bright west-northwest twilight glow shortly after sunset. Binoculars will help you spot Venus very low in twilight in its first weeks, and can reveal Mercury nearby from mid-July until late August. That’ll bring the total to all five bright planets visible simultaneously! Our chart depicting the sky at evening mid-twilight 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 hour after…
30 Apr 2016
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Make necessary preparations to safely observe the transit of Mercury across the sun on May 9. Jupiter is brightest “star” in evening sky this spring until Mars offers serious competition in late May, as the red planet presents its brightest and closest approach since 2005. The moon and Jupiter will pair up on May 14, while a “blue moon” and red Mars, at its brightest, team up on May 21. On our chart depicting the sky at evening mid-twilight in May, we find two bright stars—Rigel south of west, and Aldebaran in the west-northwest—departing early in the month. The brightest star, Sirius, the Dog Star, is next to go, in the west-southwest. All that then remains of the Winter Hexagon will be the “Spring Arch” of Procyon, Pollux (with Castor 4.5 degrees to its right) and Capella. Orion’s shoulder Betelgeuse, below the arch, drops out by late May, soon after…
30 Mar 2016
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Jupiter and Sirius—until it departs—continue to dominate the evening sky in April. This year’s best evening appearance of Mercury in mid-April precedes its transit across the Sun on May 9. Meanwhile, Mars brightens on its way to next month’s closest approach since 2005. The Mars-Saturn-Antares triangle, prominent in morning, can also be seen rising very late in evening. Don’t miss this spring’s offerings to get close-up telescopic views of some planets! First, some dates to keep in mind. April 7: The new moon occurs at 4:24 a.m., and the moon at perigee at 11 a.m. Large tides! April 8: The young crescent Moon, age 39 hours, is easy to see in twilight. Look for Mercury to the moon’s lower right. April 10: The moon occults Aldebaran in daytime; look at it with a telescope. In the evening, find this star and the Hyades cluster closely to the lower right of…