Soothing Moon 
Runners on Europa, one of the large moons of Jupiter, won’t have to go far to find relief for their aching feet. A recent study found deposits of epsomite on the moon’s icy surface — the mineral that makes up epsom salts, a remedy for tired feet and other aches.
Europa is almost as big as our own moon. Its surface is coated with ice, which appears to cap a deep ocean of liquid water.
Spacecraft that flew close to Europa detected a weak magnetic field, which could be produced by the motions of a salty ocean. And the combination of liquid water, minerals, and the energy that keeps the water from freezing suggests that Europa’s ocean could be an abode for life.
Astronomers Mike Brown and Kevin Hand studied Europa’s surface with the giant Keck II Telescope in Hawaii. They detected the chemical fingerprint of epsomite, which contains magnesium and sulfur.
The astronomers suggest the sulfur comes from volcanoes on the moon Io, which belch material far out into space. And they say the magnesium squirts to the surface from Europa’s ocean. Radiation creates chemical reactions that cause the elements to combine — adding a bit of spice to Europa’s icy surface.
Jupiter is in view early this evening, quite low in the west-northwest beginning about 20 minutes after sunset. The bright planet forms a tight triangle with brighter Venus, to its lower right, and fainter Mercury, a bit farther to the upper right. More about this conjunction tomorrow.
Script by Damond Benningfield, Copyright 2013