Seventy-nine is an impressive number of Jovian moons, but Sheppard says there are likely more waiting to be discovered.

But 12 more moons were just discovered, bringing the total to 79, the most of any planet that orbits the sun. Jupiter is not in the field but off to the upper left. Two of the new moons were actually announced last year, but all of them were spotted at roughly the same time around 2017. Elucidating the complex influences that shaped a moon’s orbital history can teach scientists about our Solar System’s early years. Eventually, the team settled on five names, which were recently approved by the International Astronomical Union (IAU). “Our other discovery is a real oddball and has an orbit like no other known Jovian moon,” Sheppard explained. Additional telescopes in Chile, Arizona, and Hawaii were used to confirm their existence and determine their orbits. Weird is good. It may come as a surprise, then, that astronomers still find new moons orbiting the largest planet in the solar system. "We think there were originally three retrograde moons each around 100 km in size, but each of these parent moons were broken apart by collisions in the past with something.".

Popular Mechanics participates in various affiliate marketing programs, which means we may get paid commissions on editorially chosen products purchased through our links to retailer sites. “There are many rules when it comes to how we name moons,” explained Sheppard in a Carnegie Science press release. “Jupiter just happened to be in the sky near the search fields where we were looking for extremely distant Solar System objects, so we were serendipitously able to look for new moons around Jupiter while at the same time looking for planets at the fringes of our Solar System,” said Sheppard. We may earn commission if you buy from a link. It just goes to show how chaotic and violent planetary formation can be. "There appear to be groups of moons with very similar orbital properties, which suggests there were once bigger moons that broke apart and we are now seeing the fragments of once bigger moons," Sheppard says. So, unlike the closer-in prograde group of moons, this new oddball prograde moon has an orbit that crosses the outer retrograde moons. Other restrictions included a maximum of 16 characters per name, and final letters had to correspond to the moon’s direction of orbit (i.e. Jupiter may be the solar system’s king, but Saturn has a bigger entourage: Today, astronomers announced that they have discovered 20 more moons … The International Astronomical Union has approved new names for five recently discovered moons around Jupiter. Proposed names could not include an offensive word in any language or culture, or commemorate living persons, among many other restrictions. The moons range in size from 1 to 3 kilometers (0.6 to 1.9 miles) wide, with Pandia being the largest among them.


This research was partially funded by a NASA Planetary Astronomy grant and includes data gathered with the 6.5-meter Magellan Telescopes.

"These moons are the last remnants of the objects that the planets were built from," Sheppard tells Popular Mechanics via email. Sheppard and his team were not even searching for Jovian moons at first, but hunting for a hypothetical giant planet in the distant realms often called Planet Nine or Planet X. By Jay Bennett.

While the original, larger Valetudo was smashed in violent collisions, the smaller remnant that exists today is probably safe—for now. Jul 17, 2018 NASA/JPL/University of Arizona. But as the press release pointed out—and to virtually no one’s surprise—many people blatantly disregarded these guidelines.

The Carnegie team had to disregard the inevitable and numerous Moony McMoonFace entries, names of favorite pets, and the like. During a quest to find Planet Nine, a mysterious planet believed to be on the edge of our solar system, astronomers discovered something else: 12 new moons around Jupiter…

It is thought to be the last surviving remnant of a larger moon that broke apart during a series of collisions as the planetary system was forming. Because of their sizes—one to three kilometers—these moons are more influenced by surrounding gas and dust. Jupiter has had its share of visitors. Jupiter has had its share of visitors. Philophrosyne (formerly S/2003 J15) is the spirit of welcome and kindness, the granddaughter of Zeus, and the sister of Eupheme.

Ersa (formerly S/2018 J1) is the “sister of Pandia and, as such, also the daughter of Zeus and the Moon goddess Selene” and “the goddess of dew,” according to the press release, to which it was added: “Being the daughter of a Moon goddess seemed very appropriate for a Jovian moon.”.

"We knew Jupiter was near our observations for distant planets and dwarf planets that are beyond Pluto, so we specifically designed our observations to be able to search for new moons of Jupiter while also searching for much more distant solar system objects," Sheppard says.

These two newly discovered moons take a little less than a year to travel around Jupiter. Otherwise we’d have to seriously consider Moony McMoonFace, which in my opinion wouldn’t be so bad. While looking for these extremely distant objects, Jupiter happened to wander into the team's field of view. The moon can be seen moving relative to the steady state background of distant stars. All entries had to be submitted via tweet, which meant participants had to make their case in 280 characters or less. “This is an unstable situation,” said Sheppard. This project used data obtained with the Dark Energy Camera (DECam), which was constructed by the Dark Energy Survey (DES) collaborating institutions. There is one mysterious moon among the retrograde group that goes against the tide, traveling in the prograde direction. Two of the small satellites were found orbiting in the "prograde group," a collection of moons that hang out just outside the four large Galilean moons (Io, Europa, Ganymede, and Callisto).

Fortuitously, the same technique for finding far-flung objects orbiting the sun works to search for small objects orbiting Jupiter. Nine of the new moons are part of a distant outer swarm of moons that orbit it in the retrograde, or opposite direction of Jupiter’s spin rotation.

The newly discovered retrograde moons take about two years to orbit Jupiter. Eirene (formerly S/2003 J5) is the goddess of peace and the daughter of Zeus and Themis. That beats Jupiter and its 79 moons. This content is created and maintained by a third party, and imported onto this page to help users provide their email addresses. The team think this small “oddball” prograde moon could be the last-remaining remnant of a once-larger prograde-orbiting moon that formed some of the retrograde moon groupings during past head-on collisions. Our solar system’s largest planet boasts a whopping 79 moons, 12 of which were discovered in early 2017. Pandia was among the most popular names entered. “It’s also likely Jupiter’s smallest known moon, being less than one kilometer in diameter”.

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"It takes several observations to confirm an object actually orbits around Jupiter, so the whole process took a year," says Gareth Williams of the International Astronomical Union Minor Planet Center, who calculated the orbits of the new moons, in a press release.

When it comes to moons, Jupiter is an embarrassment of riches. Will This Compact Reactor Finally Deliver Fusion? Pandia (formerly S/2017 J4) is the “daughter of Zeus and the Moon goddess Selene” and “the goddess of the full moon and the sister of Ersa,” according to the press release. ... Valetudo likely has collided with some of the retrograde moons in the past, and what we see today is the last remnant of a once much larger moon that has now been ground to dust. International Astronomical Union’s Minor Planet Center, Carnegie Institution for Science, 1530 P Street NW, Washington DC 20005 P: (202)-387-6400 F: (202)-387-8092. Eupheme (formerly S/2003 J3) is the spirit of praise and good omen, the granddaughter of Zeus, and the sister of Philophrosyne, according to the Carnegie Science press release. In July 2018, Scott Sheppard of the Carnegie Institution for Science announced the discovery of 12 new moons orbiting Jupiter. These distant retrograde moons are grouped into at least three distinct orbital groupings and are thought to be the remnants of three once-larger parent bodies that broke apart during collisions with asteroids, comets, or other moons.
“It takes several observations to confirm an object actually orbits around Jupiter,” Williams said. "Valetudo is like driving down the highway on the wrong side of the road.". Marine Layer Diver Dave Button Down Shirt, Former reality TV host tests positive for COVID-19, U-Haul's Motorcycle Trailer Is Really Good But You Can't Ever Own One, Last Call: Remembering the golden age of fast food buffets, Report: Warner Bros. Games President Says Transphobe J. K. Rowling Has "The Right To Hold Her Opinions". The telescope recently was upgraded with the Dark Energy Camera, making it a powerful tool for surveying the night sky for faint objects. Two of the new discoveries are part of a closer, inner group of moons that orbit in the prograde, or same direction as the planet’s rotation. "Valetudo... is likely to collide with a retrograde object head-on every billion years or so," Sheppard says, which means it could have happened multiple times in the 4.5-billion-year history of the solar system, but is highly unlikely to occur again anytime soon. The Pioneer 10 and 11 spacecraft, as well as Voyagers 1 and 2, flew by the gas giant in the 1970s.