Hipparchus (lower left) and adjacent Albategnius are ancient lunar impact craters. North on the Moon is to the left in this picture. Image credit: Marnix PraetHipparchus and Albategnius are a photogenic pair of ancient impact craters lying in the lunar central highlands just to the east of Mare Nubium. Hipparchus is much degraded and modified, due to multiple impacts that have occurred since its formation in the same impact that formed Mare Imbrium some three to four billion years ago. Hipparchus is 160 kilometres (100 miles) wide. Albategnius is a slightly smaller (136 kilometres) but magnificent walled-plain, its walls having huge peaks rising in places 3000-4250 metres (10-14000 feet) above the plain. Its central peak is 1200 metres (4000 feet) high. The smaller craters lying between the two are Halley (centre) and Hind (top), with Klein jutting into Albategniusʼ south-western (lower right) rim. The best time to observe and image the pair is at First and Last Quarter. This nice image was taken by Marnix Praet from Belgium with a ten-inch (250mm) Newtonian fitted with a 3x Televue barlow and a DMK21 camera.
When 252P/LINEAR passed just 14 lunar distances from Earth on 21 March, the comet was galloping across the far southern sky at a rate of almost ten degrees per day. Now rapidly heading north, 252P finally appears in the predawn UK sky. While moonlight will interfere with current observations, the comet is much brighter than predicted.
Life is hard for a little moon. Epimetheus, seen here with Saturn in the background, is lumpy and misshapen, thanks in part to its size and formation process.
A new Moon map provides an updated, remarkably detailed view of lunar surface geology, merging Apollo-era data with more recent observations and resolving inconsistencies in earlier maps.