February 19, 2019

AstroEvent: Exploring Clavius.

This week, as the Moon moves past 1st Quarter on the 23rd toward Full on the 30th is a good time to explore the lunar environs. Specifically, I’d like to turn your attention towards Clavius crater, a prominent feature in the southern lunar highlands. One of the largest impact craters on the Moon at 152.2 miles across, it’s large enough to actually see the lunar curvature in its structure, and houses many smaller craters within its walls. It is visible starting at 9-10 days after New Moon, and presents a slightly different face each lunation. In fact, Clavius is one of the few craters that may be discerned by keen eyed viewers with the naked eye. In a small telescope, the relatively ancient structure of Clavius contrasts well with the nearby splashiness of young Tycho. Are these ancient, broad floored craters the result of impacts, or do they suggest early volcanic activity? Most of the rocks returned by Apollo astronauts were igneous and basaltic by nature, suggesting the young Moon once had a molten crust.

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LCROSS Strikes Back!

The Moon won’t know what hit it Friday. On October 9th at 11:30 Universal Time, the LCROSS twin impactors will slam into the Moon’s south pole region. The quarry; permanently shaded water ice. LCROSS consists of a upper stage Centaur rocket weighing in at 5,200 lbs and a controlling “shepherd” spacecraft weighing in at 1,900 lbs. The stage section will separate shortly before impact, enabling the control package to fly through the resulting debris plume, which is expected to be 6 miles high at eject 350 tons of material from the surface. Both will successively slam into the surface at 5,600 mph. Recently, the candidate impact crater was shifted from Cabeus A to Cabeus proper.

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