Key facts
- Category
- Moons
- Object class
- Small inner moon
- Composition
- Porous ice and rock (rubble pile)
Amalthea
252 kmmaximum extent
252km
Visual creditGalileo 2000 / NASA / JPL / Cornell University / Public domainSource: Wikimedia Commons
Details
Amalthea is the largest of Jupiter's small inner moons, an irregular, potato-shaped body orbiting closer to the planet than Io. Imaged by Galileo, it is among the reddest objects in the Solar System, and so porous that it is likely a loosely bound rubble pile rather than solid rock.
Amalthea orbits Jupiter inside Io’s path and completes each circuit in about half an Earth day. Galileo images resolved craters, hills and valleys on its irregular body, while tracking measurements indicated a density too low for a compact rocky moon. The result supports a porous aggregate containing ice and rock. Its surface is the reddest of any known body in the Solar System, possibly from sulfur carried from volcanic Io.
Links
- Universe journey
- Asteroid belt & Jupiter
- Wikipedia
- Amalthea on Wikipedia
Size neighbors
Objects near Amalthea on the scale
On the logarithmic size axis, Amalthea falls between Phoebe and Cygnus X-1. Compared below with other objects classed as Small inner moon.
Sources
References for Amalthea
Measurements and descriptive context are compiled by the Scale of Space team from the references below. If you find an error, write to hello@scaleofspace.org.
- Amalthea on Wikipedia
- Visual reference: Wikimedia Commons (Galileo 2000 / NASA / JPL / Cornell University, Public domain)
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