Amalthea: Jupiter’s unusual inner moon

What is the News?

According to recent findings, Amalthea appears to radiate out more heat than it receives from the sun, which NASA suggests may be due to Jupiter’s magnetic field or tidal stresses.

What is Amalthea?

The moon Amalthea is one of Jupiter’s 53 named satellites. It was the first to be discovered after the four Galilean moons, and it is the fifth-largest overall.

Discovered by: Astronomer Edward Emerson Barnard discovered Amalthea in 1892 while astronomer Camille Flammarion suggested the name Amalthea after the Greek mythological figure. 

Characteristics of Amalthea

In terms of proximity to Jupiter, Amalthea is the planet’s third moon — it takes just 12 hours to make a full orbit.

Amalthea also contributes to one of the Gossamer Rings of Jupiter — the Amalthea Gossamer Ring — which is the faint innermost Gossamer ring of the planet. The Gossamer Rings are outside the main Jovian ring.

Amalthea is tidally locked to Jupiter in synchronous rotation — it always aligns with the planet along its long axis.

Major missions to Amalthea

Only two missions have visited Amalthea: Voyager and Galileo. Both the Voyager 1 and Voyager 2 spacecraft photographed the Jovian moon during their flybys in 1979.

Source: The post is based on the article “Amalthea: Jupiter’s unusual inner moon” published in Space on 14th May 2022.