http://www.universetoday.com/2008/03/20/podcast-craters/ Space and astronomy news Sun, 22 Nov 2009 03:07:54 -0600 http://wordpress.org/?v=2.8.6 hourly 1 http://www.universetoday.com/2008/03/20/podcast-craters/comment-page-1/#comment-16048 John - www.moonposter.ie Fri, 21 Mar 2008 13:06:33 +0000 http://www.universetoday.com/2008/03/20/podcast-craters/#comment-16048 Listeners can easily see one of the best examples of a low angle impact crater on the Moon -- through its resultant ejecta signature. Called, Tycho crater (85 km in diameter), it's best observed at full moon where most of the ejecta stretches predominantly in an eastwardly direction across the lunar surface. On the westside, the ejecta deposits are less; indicating that the impactor came from that direction. This type of signature produces a kind of butterfly effect -- the wings of ejecta splayed out eastwards as the impactor struck, and very little deposited in the impactor direction. Several other craters show this butterfly effect -- e.g. the 28 km-diameter Proclus crater (just west of Mare Crisium), the 32 km-diameter Kepler (in Oceanus Procellarum), and the small two craters Messier and Messier A (in Mare Fecunditatis). PS. I like how Pamela says the word 'Maria'. John -- www.moonposter.ie (the most detailed around). Listeners can easily see one of the best examples of a low angle impact crater on the Moon — through its resultant ejecta signature.
Called, Tycho crater (85 km in diameter), it's best observed at full moon where most of the ejecta stretches predominantly in an eastwardly direction across the lunar surface. On the westside, the ejecta deposits are less; indicating that the impactor came from that direction. This type of signature produces a kind of butterfly effect — the wings of ejecta splayed out eastwards as the impactor struck, and very little deposited in the impactor direction. Several other craters show this butterfly effect — e.g. the 28 km-diameter Proclus crater (just west of Mare Crisium), the 32 km-diameter Kepler (in Oceanus Procellarum), and the small two craters Messier and Messier A (in Mare Fecunditatis).
PS. I like how Pamela says the word 'Maria'.
John — http://www.moonposter.ie (the most detailed around).

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