Detail View: NASA Astronomy Picture of the Day Collection: A Spherule from the Earth's Moon
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Title:
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A Spherule from the Earth's Moon
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Explanation:
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How did this spherule come to be on the Moon? When a meteorite [ http://www.nineplanets.org/meteorites.html ] strikes the Moon [ http://antwrp.gsfc.nasa.gov/apod/moon.html ], the energy of the impact [ http://science.nasa.gov/headlines/y2001/ast30nov_1.htm ] melts some of the splattering rock [ http://www.teachersource.com/micrometeorites.htm ], a fraction of which might cool into tiny glass beads [ http://antwrp.gsfc.nasa.gov/apod/ap010523.html ]. Many of these glass beads [ http://www.geocities.com/ladysveva/BeadHistory.html ] were present in lunar soil samples [ http://www-curator.jsc.nasa.gov/curator/lunar/lunar.htm ] returned to Earth by the Apollo missions [ http://www.nasm.edu/apollo/ ]. Pictured above [ http://www.lbl.gov/Science-Articles/Archive/lunar-spherule.html ] is one such glass spherule [ http://www.hyperdictionary.com/dictionary/spherule ] that measures only a quarter of a millimeter [ http://lamar.colostate.edu/~hillger/everyday.htm ] across. This spherule [ http://antwrp.gsfc.nasa.gov/apod/ap040210.html ] is particularly interesting because it has been victim to an even smaller impact. A miniature crater [ http://antwrp.gsfc.nasa.gov/apod/ap990711.html ] is visible on the upper left, surrounded by a fragmented area caused by the shockwaves [ http://antwrp.gsfc.nasa.gov/apod/ap010623.html ] of the small impact. By dating [ http://www.dc.peachnet.edu/~pgore/geology/geo102/radio.htm ] many of these impacts, some astronomers estimate [ http://www.lbl.gov/Science-Articles/Archive/lunar-spherule.html ] that cratering [ http://antwrp.gsfc.nasa.gov/apod/ap010428.html ] on our Moon increased [ http://www.sciencenews.org/20000311/fob3.asp ] roughly 500 million years ago and continues even today.
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Credit and Copyright:
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Timothy Culler (UCB [ http://eps.berkeley.edu/www/index.html ]) et al., Apollo 11 Crew [ http://www.hq.nasa.gov/office/pao/History/alsj/a11/a11.crew.html ], NASA [ http://www.nasa.gov/ ]
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facet_where:
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Goddard Space Flight Center (GSFC)
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facet_what:
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Apollo 11
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original url:
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http://antwrp.gsfc.nasa.gov/apod/ap040215.html
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UID:
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SPD-APOD-ap040215
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