Impact histories explain differences in Jovian moons
Posted: Tue, Jan 26, 2010, 7:28 AM ET (1228 GMT)
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.
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.
Related Links:
| <<previous article | next article>> |
|
news in brief
|
|
|
|
news links
|
|
Thursday, January 15
ESA hosts China's space leaders
ESA — 5:02 am ET (1002 GMT) Starlink reportedly made free in Iran - but protesters are taking huge risks by using it
BBC — 5:02 am ET (1002 GMT) Volunteer firefighters, councils paying for Starlink connections as poor mobile reception continues across WA
Australian Broadcasting Corporation — 4:59 am ET (0959 GMT) How Iran jammed Starlink (and how Iranians are trying to get around it)
France 24 — 4:59 am ET (0959 GMT) France explores sending Eutelsat terminals to Iran amid internet blackout
Reuters — 4:57 am ET (0957 GMT) |
