Last updateWed, 27 Sep 2017 1pm


01 Jun 2015
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Venus and Jupiter in the west are closing toward a spectacular close pairing on June 30, while Saturn climbs in the southeast in the early evening. These three naked-eye planets, all showpieces for telescopic observation, should make a star party in June an exciting affair—so we hope you can arrange to attend one! Evenings: Venus and Jupiter are easy to spot until late July 2015, because they far outshine all nighttime stars. In June and July, Venus sinks lower in the evening sky while increasing in brightness and getting ever more interesting for telescopic observation: On June 6, Venus reaches greatest elongation, 45 degrees to the upper left of the setting sun; as seen through a telescope around that date, the planet appears as a tiny “half moon.” In the next 10 weeks, as Venus draws closer to Earth, it displays an ever thinner, more backlit crescent. Jupiter appears close…
01 May 2015
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In May, four of the 16 stars of first magnitude or brighter visible from Southern California begin their annual leaves of absence, sinking into the western twilight glow. In order of departure, they are Rigel, Aldebaran, Sirius and Betelgeuse. In June, Procyon, Capella and Pollux will follow—all the stars of the huge Winter Hexagon, with Betelgeuse inside. It’s enjoyable and relaxing to look for these stars within an hour after sunset on clear spring evenings. Those who watch regularly are certain to notice the stars appearing lower each evening at the same stage of twilight, and eventually dropping out of view. This change is a direct consequence of Earth’s annual revolution around the sun. As seen from Earth from late April through mid-July, the sun appears to move from Aries through Taurus into Gemini, causing these zodiac constellations and their neighbors to sink into the evening twilight glow, and, after…
31 Mar 2015
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Few people will choose to arise early to catch the start of the lunar eclipse on Saturday morning, April 4, when the spring’s first full moon begins to enter the umbra, or dark central core, of Earth’s shadow at 3:16 a.m. local time. For the next 1.7 hours, more and more of the moon will be immersed in the Earth’s circular dark shadow, until the start of the total eclipse at 4:58 a.m. Even before then, the rusty color typical of the moon in deep eclipse should be noticed—at least in the lower part of the moon’s disk, closer to the center of Earth’s shadow. Totality lasts less than five minutes, as the northern (upper) edge of the moon barely passes within the outer edge of Earth’s umbra. There should be a pronounced difference in color and brightness between the top and bottom edges of the moon. Totality ends by…