spacetoday.net: space news from around the webin association with SpaceNews


Impact histories explain differences in Jovian moons
Posted: Tue, Jan 26, 2010, 7:28 AM ET (1228 GMT)
Ganymede and Callisto interior illustration (SwRI) Differences in the number and velocity of cometary impacts can explain the differences in the surfaces and interiors of two large moons of Jupiter, scientists report. While Ganymede and Callisto are similar in size, Ganymede has clearly differentiated, with any icy surface and rocky interior, while ice and rock are mixed throughout Callisto. Southwest Research Institute scientists find that the differences can be explained by modeling impacts on the moons by comets during the early history of the solar system. Since Ganymede is closer to Jupiter, its gravity focused more comets on that moon, which also impacted at higher speeds. These additional, more energetic impacts created enough heating to melt the moon and allow its ice and rock components to differentiate, something that did not happen on Callisto. The results were published in Sunday's issue of the journal Nature Geoscience.
<<previous article   next article>>
news in brief
Rocket Lab maintains 2025 target for first Neutron launch
Posted: Sat, Mar 1 11:32 AM ET (1632 GMT)

Progress launched to ISS
Posted: Sat, Mar 1 11:23 AM ET (1623 GMT)

Falcon 9 launches IM-2 lunar lander
Posted: Sat, Mar 1 11:20 AM ET (1620 GMT)

news links
Wednesday, March 12


about spacetoday.net   ·   info@spacetoday.net   ·   mailing list