More moons discovered around Jupiter

Mindy Sparks
July 20, 2018

Diagram of the new moons split into different groups.

This screencapture shows the prograde moons of Jupiter, including the two newest discoveries.

The direction in which the moons swing around the planet depends on how they were first captured by Jupiter's gravitational field.

Which raises the question of how long the tiny moon has left.

The initial discovery of most of the new moons were made on the Blanco 4-meter telescope at Cerro Tololo Inter-American in Chile and operated by the National Optical Astronomical Observatory of the United States.

Nine of them are in previously discovered clusters of moons that are in what astronomers call a retrograde orbit. It's essentially driving down the highway in the wrong direction, Sheppard explained. Jupiter has the most moons of any other planet.

Jupiter's 79 moons make it the most orbited planet in the Solar System. So we think they're intermediate between rocky asteroids and icy comets. They exist in retrograde - going the opposite direction of Jupiter's spin rotation.

"These inner prograde moons all have similar orbital distances and angles of inclinations around Jupiter and so are thought to also be fragments of a larger moon that was broken apart". They named it Valetudo, after a daughter of Jupiter and the Roman goddess of hygiene and personal health. Sheppard's team speculates Valetudo could be a remnant of a collision between one or more moons. Maybe 100 or more of the really small ones.

The 10th new moon is the oddball.

Copyright 2018 NPR. To see more, visit There are two moons close to the planet that are spinning in the same direction.

Its four biggest moons - Io, Europa, Ganymede, and Callisto - are known as the Galilean moons because they were first spotted by Galileo Galilei in 1610. "So that's why we're able to find these new moons".

There are almost 200 moons in our solar system.

We reached out to Carnegie Institution for Science Professor Scott S. Sheppard to ask about the "oddball" description. In March a year ago, he was at the Blanco four-meter telescope in Chile.

The oddball moon crosses the orbits of the outer retrograde moons. They found 12, two of which were announced previous year.

Of course, the star of the discovery, presented during the International Astronomical Union on Tuesday, July 17, is the so-called oddball planet. The orbits of 9 other small Jovian moons are yet unknown.

PALCA: Many of Jupiter's moons form from the same spinning disk of stuff that eventually coalesce to form the planet. The team's goal was to scan the sky for evidence of a massive ninth planet in the outer solar system.

Valetudo is the smallest of the moons discovered, likely just under a kilometer wide (the size isn't measured directly - it's too small - but estimated from its brightness).

Tholen and Fohring's observations allowed the team to follow the motions of the possible moons and refine the orbits of these satellites. These astronomers said that, while the new observations were exciting, they needed to confirmed them. They found a dozen small moons.

Other reports by Iphone Fresh

Discuss This Article