Space Travel
12, Feb, 2012

Amalthea is Porous, Less Dense Than Water

Written by spacetravel.org   
Tuesday, 07 June 2005 20:58
John Anderson of NASA’s jet propulsion laboratory has reanalyzed data supplied by the Galileo spacecraft in 2002, and found that Jupiter’s innermost moon, Amalthea, is a porous mass of rock and water ice. Its density is about 85 percent that of water. It is not understood how the ice originated. Models suggest that at the time Jupiter’s inner satellites were born, the temperature 11,000 kilometers from Jupiter, which is where Amalthea now orbits, would have been too high for ice to form. Amalthea may have formed further out, and then migrated inwards, or it may have formed later than Jupiter’s other moons.