Looking east to west across the rim and down into Chaplygin crater reveals this beautiful example of a fresh young crater and its perfectly preserved ejecta blanket. The delicate patterns of flow across, over, and down local topography clearly show that ejecta traveled as a ground hugging flow for great distances, rather than simply being tossed out on a ballistic trajectory. Very near the rim lies a dark, lacy, discontinuous crust of now frozen impact melt. Clearly this dark material is on top of the bright material so it was the very last material ejected from the crater. The melt was formed as the tremendous energy of impact was converted to heat and the lunar crust was melted at the impact point. As the crater rebounded and material sloughed down the walls of the deforming crater the melt was splashed out over the rim and froze. Its low reflectance is mostly due to a high percentage of glass because the melt cooled so quickly that minerals did not have time to crystallize. The fact that the delicate splash patterns are so well preserved testifies to the very young age of this crater. But how young? For comparison "Chappy" (informal name) is 200 m larger than Meteor crater (1200 m diameter) in Arizona, which is about 50,000 years old. Craters of this size form every 100,000 years or so on the Moon and the Earth. Since there are very few superposed craters on Chappy, and its ejecta is so perfectly preserved it may be much younger than Meteor crater. However, we can't know the true true absolute age of "Chappy" until we can obtain a sample of its impact melt for radiometric age dating. Investigate all of Chappy's ejecta, at full resolution: <a href="http://lroc.sese.asu.edu/posts/901" rel="nofollow">lroc.sese.asu.edu/posts/901</a> Credit: NASA/Goddard/Arizona State University/LRO/LROC

Chappy Oblique

Looking east to west across the rim and down into Chaplygin crater reveals this beautiful example of a fresh young crater and its perfectly preserved ejecta blanket. The delicate patterns of flow across, over, and down local topography clearly show that ejecta traveled as a ground hugging flow for great distances, rather than simply being tossed out on a ballistic trajectory. Very near the rim lies a dark, lacy, discontinuous crust of now frozen impact melt. Clearly this dark material is on top of the bright material so it was the very last material ejected from the crater. The melt was formed as the tremendous energy of impact was converted to heat and the lunar crust was melted at the impact point. As the crater rebounded and material sloughed down the walls of the deforming crater the melt was splashed out over the rim and froze. Its low reflectance is mostly due to a high percentage of glass because the melt cooled so quickly that minerals did not have time to crystallize. The fact that the delicate splash patterns are so well preserved testifies to the very young age of this crater. But how young? For comparison "Chappy" (informal name) is 200 m larger than Meteor crater (1200 m diameter) in Arizona, which is about 50,000 years old. Craters of this size form every 100,000 years or so on the Moon and the Earth. Since there are very few superposed craters on Chappy, and its ejecta is so perfectly preserved it may be much younger than Meteor crater. However, we can't know the true true absolute age of "Chappy" until we can obtain a sample of its impact melt for radiometric age dating. Investigate all of Chappy's ejecta, at full resolution: <a href="http://lroc.sese.asu.edu/posts/901" rel="nofollow">lroc.sese.asu.edu/posts/901</a> Credit: NASA/Goddard/Arizona State University/LRO/LROC

NASA's LRO Discovers Lunar Hydrogen More Abundant on Moon's Pole-Facing Slopes

Space travel is difficult and expensive – it would cost thousands of dollars to launch a bottle of water to the moon. The recent discovery of hydrogen-bearing molecules, possibly including water, on the moon has explorers excited because these deposits could be mined if they are sufficiently abundant, sparing the considerable expense of bringing water from Earth. Lunar water could be used for drinking or its components – hydrogen and oxygen – could be used to manufacture important products on the surface that future visitors to the moon will need, like rocket fuel and breathable air. Recent observations by NASA's Lunar Reconnaissance Orbiter (LRO) spacecraft indicate these deposits may be slightly more abundant on crater slopes in the southern hemisphere that face the lunar South Pole. "There’s an average of about 23 parts-per-million-by-weight (ppmw) more hydrogen on Pole-Facing Slopes (PFS) than on Equator-Facing Slopes (EFS)," said Timothy McClanahan of NASA's Goddard Space Flight Center in Greenbelt, Maryland. This is the first time a widespread geochemical difference in hydrogen abundance between PFS and EFS on the moon has been detected. It is equal to a one-percent difference in the neutron signal detected by LRO's Lunar Exploration Neutron Detector (LEND) instrument. McClanahan is lead author of a paper about this research published online October 19 in the journal Icarus. Read more: <a href="http://1.usa.gov/1uaa8s2" rel="nofollow">1.usa.gov/1uaa8s2</a> Photo caption: LRO image of the moon's Hayn Crater, located just northeast of Mare Humboldtianum, dramatically illuminated by the low Sun casting long shadows across the crater floor. Image Credit: NASA/GSFC/Arizona State University <a href="http://www.nasa.gov/audience/formedia/features/MP_Photo_Guidelines.html" rel="nofollow">NASA image use policy.</a> <a href="http://www.nasa.gov/centers/goddard/home/index.html" rel="nofollow">NASA Goddard Space Flight Center</a> enables NASA’s mission through four scientific endeavors: Earth Science, Heliophysics, Solar System Exploration, and Astrophysics. Goddard plays a leading role in NASA’s accomplishments by contributing compelling scientific knowledge to advance the Agency’s mission. Follow us on <a href="http://twitter.com/NASAGoddardPix" rel="nofollow">Twitter</a> Like us on <a href="http://www.facebook.com/pages/Greenbelt-MD/NASA-Goddard/395013845897?ref=tsd" rel="nofollow">Facebook</a> Find us on <a href="http://instagram.com/nasagoddard?vm=grid" rel="nofollow">Instagram</a>