Astronomers have found a new harvest of moons around Jupiter, and one of them is a nutty

Ten more moons were confirmed in orbit around Jupiter, bringing to 79 the total number of known satellites on the planet. It is the highest number of moons of any planet in the solar system. And these newly discovered space rocks give astronomers a glimpse of why the Jupiter system looks like what it is today.

Astronomers from the Carnegie Institution for Science found these moons in March 2017, as well as two others already confirmed in June. last year. The team initially found the 12 moons using the 4-meter Blanco telescope in Chile, although the discovery of these objects was not their primary goal. Instead, they were looking for incredibly distant objects – or even planets – that might be hiding in our solar system beyond Pluto. But while they were looking for these rocks in marginal space, they decided to take a look at what could be hiding around Jupiter at the same time. Now, the moons they found have been observed several times, and their exact orbits have been submitted to the approval of the International Astronomical Union, which officially recognizes the celestial bodies.

These moons are all tiny, between less than a mile and nearly two miles wide. And they break down into three different types. Two orbits closer to Jupiter, moving in the same direction as the planet turns. Further away from these, about 15.5 million miles from the planet, there are nine that turn in the opposite direction, moving against the rotation of Jupiter. But in this same far-off region, a strange moon that astronomers call Valetudo moves with the spin of Jupiter, like the two inner moons. This means that it goes in the opposite direction of all the other moons in the same area. "It's essentially driving down the road in the wrong direction," Scott Sheppard, an astronomer at Carnegie who led the discovery team, tells The Verge . "It's a very unstable situation, frontal collisions are likely to occur in this situation."

Valetudo is not the only moon of Jupiter that acts this way. Another moon called Carpo is also in orbit away from Jupiter, moving in the opposite direction of many other moons in the region. However, Valetudo orbits much further than Carpo, and it is perhaps the smallest moon of Jupiter. Now, with this discovery, astronomers believe that it's a good proof that moon-on-moon collisions have occurred in Jupiter's past, and that they are responsible for the lunar landscape around the planet. aujourd & # 39; hui. "Valetudo, just 1 kilometer in diameter, is probably the last vestige of a much larger moon that has been reduced to dust over time," Sheppard explains. As the largest planet in our solar system, it has a very large area of ​​influence, so there is a lot of space where the moons could potentially be. It is difficult to search this area in a timely manner with a telescope. "It's like looking through a straw, and you cover as many points around Jupiter as you can to look for those things," says Sheppard. And since Jupiter is so big, it reflects a lot of light. This means that there can be a lot of glare when looking for super-weak moons around the planet.

Fortunately, the 4-meter Blanco telescope that scientists used was the perfect equipment to find these moons. It has the largest camera of any high-class telescope out there, and it has allowed astronomers to cover a large area of ​​space around Jupiter in a shorter amount of time. In addition, Blanco's camera is well shaded, according to Sheppard, which helps to reduce the glare and light scattered by Jupiter

. distant and weak objects, that is why Carnegie scientists used the telescope to do a massive study of bodies beyond Pluto. Scanning the night sky in March of last year, the team noticed that Jupiter was directly above the sky. They decided to do several things at once: they would look for objects moving at about the same rate as Jupiter – potential moons – as well as objects moving much more slowly in the distant Solar System. After identifying 12 possible Jupiter moons, they re-observed the planet a month later and then again in May of this year with different telescopes to confirm what they had seen.

Sheppard believes that this new lineage tells a story about Jupiter's past. Astronomers claim that these nine moons, all moving in the same direction away from Jupiter, may actually be pieces of a larger moon that existed long ago. Some of them share specific traits with each other, like the same orbital angles, which makes scientists think that these moons are actually fragments of three larger moons. "We think, originally, that there were three parent organizations, and, one way or another, each of these parent organs broke down. And a big question is: what broke these objects? "Says Sheppard. It is there that Valetudo intervenes. With such a nearby moon, it is possible that many frontal collisions occur, reducing these objects to the small sizes that we see today.

All these new moons are exciting for astronomers because they add to an already large group of objects around Jupiter that comes from the early days of the solar system. Unlike the great inner moons of the planet, like Europa and Io, this large cache of orbiting moons far from Jupiter is supposed to be made of the same material that served as building blocks for the planets. These pieces of rock and dust probably floated around the Sun as it was forming, and rather than forming other planets, they were captured by the gargantuan gravitational pull of Jupiter. How that happened, however, is still a bit of a mystery. "The question we want to ask ourselves if we want to understand how Jupiter is formed is how the environment allowed the capture of moons, and how many moons were captured?" Said Douglas Hamilton, a University of Maryland astronomer who was not part of the Discovery Team

But it is possible that other moons are hiding around Jupiter, waiting to be seen. And the more we locate, the more we learn how Jupiter has become the planet that she is today. "What we see is only the tip of the iceberg," Hamilton says. "The smaller we are, the more we find moons."