What are Jupiter’s rings made of, how big are they and how were they formed?
The innermost halo ring stretches from around 92,000km (57,000 miles) to just over 120,000km (78,000) and is the thickest of Jupiter’s rings through the vertical. It’s shaped like a torus and is significantly less bright than the main ring despite being many times wider and thicker. The dust particles that the Halo ring is composed of are less than 15 micrometres in diameter and are mostly derived from the main ring.
This narrow ring is just 6,500km (4,000 miles) wide and stretches from 122,500km (76,000 miles) and 129,000km (80,000 miles). It’s the brightest of the rings and fringes on Adrastea, the smallest of Jupiter’s four inner moons. The main ring’s dusty composition isn’t evenly distributed and is divided into regions of varied thickness that scatter light more effectively than the other rings. Still, it was faint enough to be missed by the Hubble Space Telescope and wasn’t detected until Keck viewed it in 2002.
Amalthea gossamer ring
The innermost gossamer ring runs from the border of the main ring to around 182,000km (113,000 miles), decreasing in thickness towards Jupiter. The ring gets its name from the Jovian moon Amalthea, a 160km (99 mile) diameter rock that orbits right through the centre of the Amalthea gossamer ring. As it passed through the gossamer rings in 2002, the Galileo spacecraft detected small bodies of less than 1km (0.6 miles) near Amalthea, which are likely the debris caused by numerous collisions.
Thebe gossamer ring
Like Jupiter’s other rings, the Thebe gossamer ring is composed of dust from impacts with the Jovian moons. It’s the faintest of the rings and stretches far out to the orbit of the moon of Thebe at 226,000km (140,000 miles). However, scientists are unable to explain the extension of the Thebe ring’s orbit, which could be due to the influence of Jupiter’s magnetosphere or even objects on the outside of the Thebe ring that are as yet unseen.