Key facts
- Category
- Moons
- Object class
- Small inner moon
- Composition
- Porous ice and rock (rubble pile)
Amalthea
252 kmmaximum extent
Explore Amalthea to scaleVisual 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 strikingly red — 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 exceptionally red surface may include material transported from volcanic Io, but that source is an interpretation rather than a direct compositional measurement.
Links
- Wikipedia
- Amalthea on Wikipedia
Size neighbors
Objects near Amalthea on the scale
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, please let us know.
- Amalthea — Wikipedia
- Visual reference: Wikimedia Commons (Galileo 2000 / NASA / JPL / Cornell University, Public domain)
Continue with nearby objects or open the full scale.
About
Scale of Space is a scroll-based journey through the universe, placing objects on a single logarithmic scale so you can compare size across an unbroken range.
Guides explain selected parts of that range, while focused views filter the objects by subject.