Friday, June 14
First Quarter Moon occurs at 1:18 A.M. EDT this morning. At 9:35 A.M. EDT, the Moon reaches apogee, the farthest point from Earth in its orbit. It will then sit 251,082 miles (404,077 kilometers) away.
By evening, the Moon is setting in the west, standing amid the sparkling stars of Virgo. In just two days’ time, Luna will pass within 2° of the Maiden’s alpha star, magnitude 1 Spica. For now, the Moon floats nearly 20.5° west of this star, about halfway between Gamma (γ) and Beta (β) Virginis. As sunrise reaches halfway across the nearside, the eastern half of the Moon’s face appears lit, including the Sea of Serenity in the lunar northeast.
Turn your telescope toward this broad, dark feature. On the southern rim of this dark, lava-filled “sea” sits the 15-mile-wide (24 km) crater Menelaus. To its northeast is the small, circular pockmark Bessel, which almost appears to sit alone in a vast sea of volcanic plains. Do you see a lighter streak of material that almost appears to bisect the mare, passing up from Menelaus through Bessel and beyond?
It’s tempting to think this ray of thrown-up material is from Menelaus’ impact — but it’s not. This ray actually traces its origin all the way back to the mighty Tycho in the lunar south, which sits just on the terminator separating lunar night from day tonight. Over the next two days, the terminator will move steadily west, better revealing Tycho and its surroundings, including much of the impressive ray system streaking away from this 53-mile-wide (85 km) crater.
Mercury reaches superior conjunction at 1 P.M. EDT. It will soon become visible in the evening sky; we’ll try to catch it later this week, but chances are it won’t be easy to see until next week.
