Thursday December 12, 2013; 05:58 am EST
Sky Watch - Summer’s Shortest Nights
The waxing moon reaches first-quarter phase Friday, appearing high in the southwest with sunset at 8:24. Each night after, the moon appears 15 degrees farther to the east and sets roughly 30 minutes later.
Thursday the moon shines less than 10 degrees to the right of Mars, well within the space of your fist held at arm’s length. A little beyond Mars shines Regulus, the heart of Leo the lion. While Mars is only a little brighter than its apparent stellar neighbor, the planet’s steady orange-hued glow stands out in stark contrast to the twinkling blue-white light of Regulus.
That same night, Saturn shines 20 degrees to the moon’s left flank. Then on Friday, the moon is less than 10 degrees below the ringed planet. By Sunday, the moon is almost due south at sunset, with the brilliant star Spica just a few degrees above the moon.
Venus shines so bright that with clear skies you can see her glowing in the east even before sunset. And despite darkening skies, your best chance to watch this evening star is right after dusk, as she quickly follows the sun to the horizon. Sunday Venus pulls within one degree of the Beehive Cluster at the center of the constellation Cancer. With the naked eye, this cluster appears as little more than a smudge of light; with binoculars, hundreds of stars pop into focus.
Jupiter rises in the east after 1am, and is high in the south before sunrise, around 5:40 this week. He is hard to miss, perched in the darkest part of the night sky.
Monday at 7:28am, the sun reaches its northernmost apex of the year, stopping in its tracks above the Tropic of Cancer, 231x2 degrees — not by coincidence the same as the angle of earth’s tilted axis — north of the equator. This marks the onset of summer in the Northern Hemisphere. This is the longest day of the year, with the sun rising at 5:40 and setting almost 15 hours later at 8:35.