Amalthea

Small, inner satellite of Jupiter discovered in 1892 by the American astronomer E.E. Barnard. It circles Jupiter once every 11 h 57 min at a distance of 181,000 km (112,220 miles) in a nearly circular, uninclined orbit. Photographs transmitted by the U.S. probes Voyagers 1 and 2 in 1979 show that Amalthea is an irregular body measuring 270 � 166 � 150 km (167 � 103 � 93 miles); the long axis always points toward Jupiter. Amalthea has a very