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.
At 6am GMT on the mornings of 3 and 4 February, around the onset of astronomical twilight for the centre of the British Isles, the old waning crescent Moon brushes by ringed planet Saturn low to the south-southeast horizon. As a bonus for telescope users, the Moon occults globular cluster M9 shortly after 6am GMT on 4 February too.
A crucial difference in the isotopic chemical “fingerprints” of Earth and the Moon confirms an explosive, interconnected past when, within the first 150 million years after our Solar System formed, a giant body roughly the size of Mars struck the Earth.
Did the “Man in the Moon” look different from ancient Earth? New NASA-funded research provides evidence that the spin axis of the Moon shifted by about five degrees roughly three billion years ago. The evidence of this motion is recorded in the distribution of ancient lunar ice, evidence of delivery of water to the early solar system.