Himalia, a Small Moon of Jupiter
January 23, 2001
NASA's Cassini spacecraft captured images of Himalia, the brightest of Jupiter's
outer moons, on Dec. 19, 2000, from a distance of 4.4 million kilometers
(2.7 million miles).
This near-infrared image, with a resolution of about 27 kilometers (17 miles)
per pixel, indicates that the side of Himalia facing the spacecraft is roughly
160 kilometers (100 miles) in the up-down direction. Himalia probably has a
non-spherical shape. Scientists believe it is a body captured into orbit
around Jupiter, most likely an irregularly shaped asteroid.
In the main frame, an arrow indicates Himalia. North is up. The inset shows
the little moon magnified by a factor of 10, plus a graphic indicating
Himalia's size and the direction of lighting (with sunlight coming from the
left). Cassini's pictures of Himalia were taken during a brief period when
Cassini's attitude was stabilized by thrusters instead of by a steadier
reaction-wheel system. No spacecraft or telescope had previously shown any
of Jupiter's outer moons as more than a star-like single dot.
Cassini is a cooperative project of NASA, the European Space Agency and the
Italian Space Agency. The Jet Propulsion Laboratory, a division of the
California Institute of Technology in Pasadena, manages the Cassini mission
for NASA's Office of Space Science, Washington, D.C.
Credit: NASA/JPL/University of Arizona