Another discovery made by the space probes is the ring that circles Jupiter, which is absolutely invisible from the Earth. The first clue indicating its presence was found in 1974 by Pioneer 10, which recorded a reduction in the number of high-energy particles which surround the planet, in a strip that runs around the equator at a distance of between 50 000 and 55 000 kilometers from the highest layers of the Jovian atmosphere. This may have been an unknown satellite, which was "sweeping" away the particles it encountered, or perhaps a ring. The second theory turned out to be the correct one, as demonstrated by the two Voyager missions which, five years later, photographed this unique structure. Thus, it was discovered that the ring has a width of about 6 000 kilometers and that its external edge is 58 000 kilometers from the planet. Only thirty kilometers thick, it consists of rocky reddish fragments that are so small that they can only intercept a thousandth of the solar light that crosses them: this is why the ring is almost transparent and therefore invisible even for the most powerful telescopes. Within the ring, there is a diffuse disk composed of even smaller and rarefied particles. This disk probably extends up to the upper layers of Jupiter's atmosphere. The disk and the ring are surrounded by a type of luminous halo, with a thickness of 20 000 kilometers, which extends slightly farther than the most external portion of the ring. But how was this fascinating structure formed? Like with the other outer planets, such as Saturn and Uranus, which have a system of rings, scientists have come up with basically two theories. The first theory states that a single external body, perhaps a meteorite, collided with a small satellite at that point, disintegrating together and thus creating the material that today we see rotating in a band around the planet. Instead, the second hypothesis states that the rings are the remains of the matter that gradually created the planet. Unable to aggregate, this matter continued to revolve around the planet.
Another discovery made by the space probes is the ring that circles Jupiter, which is absolutely invisible from the Earth. The first clue indicating its presence was found in 1974 by Pioneer 10, which recorded a reduction in the number of high-energy particles which surround the planet, in a strip that runs around the equator at a distance of between 50 000 and 55 000 kilometers from the highest layers of the Jovian atmosphere. This may have been an unknown satellite, which was "sweeping" away the particles it encountered, or perhaps a ring. The second theory turned out to be the correct one, as demonstrated by the two Voyager missions which, five years later, photographed this unique structure. Thus, it was discovered that the ring has a width of about 6 000 kilometers and that its external edge is 58 000 kilometers from the planet. Only thirty kilometers thick, it consists of rocky reddish fragments that are so small that they can only intercept a thousandth of the solar light that crosses them: this is why the ring is almost transparent and therefore invisible even for the most powerful telescopes. Within the ring, there is a diffuse disk composed of even smaller and rarefied particles. This disk probably extends up to the upper layers of Jupiter's atmosphere. The disk and the ring are surrounded by a type of luminous halo, with a thickness of 20 000 kilometers, which extends slightly farther than the most external portion of the ring. But how was this fascinating structure formed? Like with the other outer planets, such as Saturn and Uranus, which have a system of rings, scientists have come up with basically two theories. The first theory states that a single external body, perhaps a meteorite, collided with a small satellite at that point, disintegrating together and thus creating the material that today we see rotating in a band around the planet. Instead, the second hypothesis states that the rings are the remains of the matter that gradually created the planet. Unable to aggregate, this matter continued to revolve around the planet.
