This Week's Sky at a Glance...........from Sky & Telescope Magazine

Friday, May 9
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  • As twilight fades this evening, there's a lot going on across the western side of the sky. The Moon hangs just below the lengthening line of Mars, Pollux, and Castor, as shown at right. Down to their lower left shines Procyon. Farther to their lower right twinkles Capella (out of the frame). And the Saturn-Regulus pair poses high off to the upper left.
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  • And there's more going on lower down! Between 8 and 9 p.m. daylight saving time (depending where you live in your time zone), viewers at mid-northern latitudes can see Mercury at exactly the same altitude in the west-northwest as Vega is on the other side of the sky in the northeast — on the night they're exactly the same magnitude, 0.0. Clear, unobstructed horizons are important, as both will be less than about 9° high. (Thanks to David Likuski for spotting this event.)

     

    Saturday, May 10

     

  • The Moon, nearly first quarter now, forms a long arc with Mars, Pollux, and Castor, as shown above. Seen from eastern North America this evening, the Moon skims the edge of the Beehive star cluster (M44); use binoculars or a telescope at low power.

     

    Sunday, May 11

     

  • First-quarter Moon (exact at 11:47 p.m. Eastern Daylight Time).

     

    Monday, May 12

     

  • Saturn and Regulus shine to the right of the Moon this evening, as shown here.

     

    Tuesday, May 13

     

  • Face southeast after dark and look very high for bright Arcturus, 37 light-years away. Look low in the northeast for equally bright Vega, 25 light-years away. These are the two brightest stars of late spring and summer. Their nearness has a lot to do with this; stars visible to the unaided eye are typically 100 to more than 1,000 light-years distant.

     

    Wednesday, May 14

     

  • Look a third of the way from Arcturus to Vega for the dim little semicircle of Corona Borealis, the Northern Crown. It's highlighted by one modestly bright star, Gemma or Alphecca, magnitude 2.2.

    Then look two thirds of the way from Arcturus to Vega for the Keystone of Hercules, highlighted by nothing at all.

     

    Thursday, May 15

     

  • A small telescope will always show Titan, Saturn's largest and wildest moon. Tonight through Saturday, Titan is three or four ring-lengths to Saturn's west. A 6-inch telescope will begin to show the orange color of its smoggy atmosphere. A guide to identifying all six of Saturn's satellites that are sometimes visible in amateur scopes is in the May Sky & Telescope, page 60.

     

    Friday, May 16

     

  • Look above the waxing gibbous Moon this evening for the hot star Spica, pale blue-white. Arcturus is far off to their upper left.

     

    Saturday, May 17

     

  • How low can you see to your north horizon? That's where you'll find W-shaped Cassiopeia around 10 or 11 p.m. this week. If you're far enough north, that is! From the latitudes of Atlanta, Houston, and San Diego, part of the Cassiopeia W will be below the horizon. From South Florida, the W goes below the north horizon completely.