Author Archives: Alan MacRobert

About Alan MacRobert

Sky & Telescope senior editor Alan MacRobert has been covering all aspects of astronomy since 1982.

This Week's Sky at a Glance logo

This Week’s Sky at a Glance, May 25 – June 2

  Friday, May 25 • As the waxing gibbous Moon crosses the sky tonight, Spica hangs below it, as shown in early twilight here. • The Arch of Spring spans the western sky in late twilight, arching over Venus. Pollux and Castor form the Arch's top; they're lined up over Venus roughly horizontally. Look well…

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This Week’s Sky at a Glance, April 20 – 28

Friday, April 20 • This evening the dark limb of the crescent Moon will occult 4th-magnitude multiple star Nu Geminorum, in the feet of Gemini, for parts of the southern U.S. and points south. For rough time estimates at your location, interpolate between the time predictions in the April Sky & Telescope, page 48. Saturday,…

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This Week’s Sky at a Glance, March 9 – 17

  Friday, March 9 • Just after twilight fades away this week, bright Sirius stands due south on the meridian. Sirius is the bottom star of the equilateral Winter Triangle. The Triangle's other two stars are orange Betelgeuse (Orion's shoulder) to Sirius's upper right, and Procyon to Sirius's upper left. • In early dawn Saturday…

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This Week’s Sky at a Glance, February 23 – March 3

  Friday, February 23 • First-quarter Moon (exact at 3:09 a.m. on this date EST). For North America this evening, the Moon shines left or upper left of Aldebaran, and farther upper right of Orion, as shown here. The Moon occults Aldebaran in daylight or twilight for northern and western Europe, and in darkness for…

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This Week’s Sky at a Glance, February 2 – 10

The Winter Hexagon fills the sky toward the east and south these evenings. Start with brilliant Sirius at its bottom. Going clockwise from there, march up through Procyon, Pollux and Castor, Menkalinan and Capella on high, down to Aldebaran, then to Rigel in Orion's foot, and back to Sirius.

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This Week’s Sky at a Glance, January 12 – 20

Friday, January 12 • Sirius, the Dog Star, rises in the east-southeast around the end of twilight now, if you're near latitude 40° north (New York, Denver, Madrid, Athens). From such latitudes, Procyon — left of Sirius, by 2½ fists at arm's length — precedes it up; "Procyon" is from the ancient Greek for "before…