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Exploratour - The Surface of Europa

The cratered surface of Jupiter's moon, and Europa's neighbor, Callisto.
Click on image for full size
NASA

The significance of the lack of craters is this. There was a period of heavy bombardment of planetary surfaces by craters at the conclusion of the formation of the solar system. The surfaces of most solar system bodies also stopped forming at or near this time, preserving the record of cratering. However, the surfaces of some planets/moons continued to change long after this period stopped due to interior activity, wiping out the record of cratering which appears of the planet's surface. Thus the number of craters on a surface help scientists pinpoint the age of a surface

With each new picture, the lack of craters suggested that the age of Europa's surface was younger and younger. First scientists thought it was 3 billions years old, then they guessed it was only 1 million years old, then 10,000 years old, and finally they guessed that it might be currently active!

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ExploraTour - Looking at the World in a Different Light

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ExploraTour - Looking at the World in a Different Light

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ExploraTour - Looking at the World in a Different Light

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ExploraTour - Looking at the World in a Different Light

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Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA