This Hubble telescope image of the giant planet Jupiter reveals the impact sites of two fragments from comet Shoemaker-Levy 9. Twenty-one large chunks of the comet rained down upon Jupiter in July 1994. The impact sites, located in the planet's Southern Hemisphere, are the dark spots in the upper left of the photograph.

The solar system's largest planet has some "new" neighbors.

Astronomers have discovered 12 additional moons in orbit around Jupiter, bringing the total to 79, the most of any planet in the solar system, a new study found.

The moons were discovered while astronomers were searching for objects at the edge of the solar system, according to Scott Sheppard, a scientist at the Carnegie Institution for Science who co-authored the study.

“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,” Sheppard said.

One of the objects they were looking for is the mysterious "Planet X" or "Planet Nine," which remains undiscovered.

The discovery of the new moons was reported Tuesday in the Minor Planet Electronic Circular, a publication of the International Astronomical Union.

Researchers say the new Jupiter moons weren’t seen before because they are tiny – the biggest ones are only about two miles across.

One of the newly discovered moons is an "oddball," Sheppard said. "It has an orbit like no other known Jovian moon,” he explained. It orbits in an opposite direction from the other moons near it, meaning head-on collisions are much more likely to occur.

“This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.

“It’s also likely Jupiter’s smallest known moon, being less than one kilometer (0.6 mile) in diameter."

Telescopes in Chile, Hawaii and Arizona were used for the original discovery and year-long confirmation of the moons.

“It takes several observations to confirm an object actually orbits around Jupiter,” said Gareth Williams of the International Astronomical Union’s Minor Planet Center. “So, the whole process took a year.”

Legendary Italian scientist Galileo first detected Jupiter’s four largest moons, Io, Europa, Ganymede and Callisto in 1610.</s>Astronomers are still finding moons at Jupiter, 400 years after Galileo used his spyglass to spot the first ones.

NEW YORK — Astronomers are still finding moons at Jupiter, 400 years after Galileo used his spyglass to spot the first ones.

The latest discovery of a dozen small moons brings the total to 79, the most of any planet in our solar system.

Scientists were looking for objects on the fringes of the solar system last year when they pointed their telescopes close to Jupiter’s backyard, according to Scott Sheppard of the Carnegie Institute for Science in Washington. They saw a new group of objects moving around the giant gas planet but didn’t know whether they were moons or asteroids passing near Jupiter.

“There was no eureka moment,” said Sheppard, who led the team of astronomers. “It took a year to figure out what these objects were.”

They all turned out to be moons of Jupiter. The confirmation of 10 was announced Tuesday. Two were confirmed earlier.

The moons had not been spotted before because they are tiny. They are about one to two miles across, said astronomer Gareth Williams of the International Astronomical Union’s Minor Planet Center.

And he thinks Jupiter might have even more moons just as small waiting to be found.

“We just haven’t observed them enough,” said Williams, who helped confirm the moons’ orbits.

The team is calling one of the new moons an ‘oddball’ because of its unusual orbit. Sheppard’s girlfriend came up with a name for it: Valetudo, the great-granddaughter of the Roman god Jupiter.

Valetudo is in Jupiter’s distant, outer swarm of moons that circles in the opposite direction of the planet’s rotation. Yet it’s orbiting in the same direction as the planet, against the swarm’s traffic.

“This moon is going down the highway the wrong way,” Sheppard said.

Scientists believe moons like Valetudo and its siblings appeared soon after Jupiter formed. The planet must have acted like a vacuum, sucking up all the material that was around it. Some of that debris was captured as moons.

“What astonishes me about these moons is that they’re the remnants of what the planet formed from,” he said.

Telescopes in Chile, Hawaii and Arizona were used for the latest discovery and confirmation.

Galileo detected Jupiter’s four largest moons, Io, Europa, Ganymede and Callisto in 1610. The latest count of 79 known planets includes eight that have not been seen for several years. Saturn is next with 61, followed by Uranus with 27 and Neptune with 14. Mars has two, Earth has one and Mercury and Venus have none.</s>This Hubble telescope image of the giant planet Jupiter reveals the impact sites of two fragments from comet Shoemaker-Levy 9. Twenty-one large chunks of the comet rained down upon Jupiter in July 1994. The impact sites, located in the planet's Southern Hemisphere, are the dark spots in the upper left of the photograph.

The solar system's largest planet has some "new" neighbors.

Astronomers have discovered 12 additional moons in orbit around Jupiter, bringing the total to 79, the most of any planet in the solar system, a new study found.

The moons were discovered while astronomers were searching for objects at the edge of the solar system, according to Scott Sheppard, a scientist at the Carnegie Institution for Science who co-authored the study.

“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,” Sheppard said.

One of the objects they were looking for is the mysterious "Planet X" or "Planet Nine," which remains undiscovered.

The discovery of the new moons was reported Tuesday in the Minor Planet Electronic Circular, a publication of the International Astronomical Union.

Researchers say the new Jupiter moons weren’t seen before because they are tiny – the biggest ones are only about two miles across.

One of the newly discovered moons is an "oddball," Sheppard said. "It has an orbit like no other known Jovian moon,” he explained. It orbits in an opposite direction from the other moons near it, meaning head-on collisions are much more likely to occur.

“This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.

“It’s also likely Jupiter’s smallest known moon, being less than one kilometer (0.6 mile) in diameter."

Telescopes in Chile, Hawaii and Arizona were used for the original discovery and year-long confirmation of the moons.

“It takes several observations to confirm an object actually orbits around Jupiter,” said Gareth Williams of the International Astronomical Union’s Minor Planet Center. “So, the whole process took a year.”</s>This Hubble telescope image of the giant planet Jupiter reveals the impact sites of two fragments from comet Shoemaker-Levy 9. Twenty-one large chunks of the comet rained down upon Jupiter in July 1994. The impact sites, located in the planet's Southern Hemisphere, are the dark spots in the upper left of the photograph.

The solar system's largest planet has some "new" neighbors.

Astronomers have discovered 12 additional moons in orbit around Jupiter, bringing the total to 79, the most of any planet in the solar system, a new study found.

The moons were discovered while astronomers were searching for objects at the edge of the solar system, according to Scott Sheppard, a scientist at the Carnegie Institution for Science who co-authored the study.

“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,” Sheppard said.

One of the objects they were looking for is the mysterious "Planet X" or "Planet Nine," which remains undiscovered.

The discovery of the new moons was reported Tuesday in the Minor Planet Electronic Circular, a publication of the International Astronomical Union.

Researchers say the new Jupiter moons weren’t seen before because they are tiny – the biggest ones are only about two miles across.

One of the newly discovered moons is an "oddball," Sheppard said. "It has an orbit like no other known Jovian moon,” he explained. It orbits in an opposite direction from the other moons near it, meaning head-on collisions are much more likely to occur.

“This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.

“It’s also likely Jupiter’s smallest known moon, being less than one kilometer (0.6 mile) in diameter."

Telescopes in Chile, Hawaii and Arizona were used for the original discovery and year-long confirmation of the moons.

“It takes several observations to confirm an object actually orbits around Jupiter,” said Gareth Williams of the International Astronomical Union’s Minor Planet Center. “So, the whole process took a year.”</s>This Hubble telescope image of the giant planet Jupiter reveals the impact sites of two fragments from comet Shoemaker-Levy 9. Twenty-one large chunks of the comet rained down upon Jupiter in July 1994. The impact sites, located in the planet's Southern Hemisphere, are the dark spots in the upper left of the photograph.

The solar system's largest planet has some "new" neighbors.

Astronomers have discovered 12 additional moons in orbit around Jupiter, bringing the total to 79, the most of any planet in the solar system, a new study found.

The moons were discovered while astronomers were searching for objects at the edge of the solar system, according to Scott Sheppard, a scientist at the Carnegie Institution for Science who co-authored the study.

“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,” Sheppard said.

One of the objects they were looking for is the mysterious "Planet X" or "Planet Nine," which remains undiscovered.

The discovery of the new moons was reported Tuesday in the Minor Planet Electronic Circular, a publication of the International Astronomical Union.

Researchers say the new Jupiter moons weren’t seen before because they are tiny – the biggest ones are only about two miles across.

One of the newly discovered moons is an "oddball," Sheppard said. "It has an orbit like no other known Jovian moon,” he explained. It orbits in an opposite direction from the other moons near it, meaning head-on collisions are much more likely to occur.

“This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.

“It’s also likely Jupiter’s smallest known moon, being less than one kilometer (0.6 mile) in diameter."

Telescopes in Chile, Hawaii and Arizona were used for the original discovery and year-long confirmation of the moons.

“It takes several observations to confirm an object actually orbits around Jupiter,” said Gareth Williams of the International Astronomical Union’s Minor Planet Center. “So, the whole process took a year.”</s>This Hubble telescope image of the giant planet Jupiter reveals the impact sites of two fragments from comet Shoemaker-Levy 9. Twenty-one large chunks of the comet rained down upon Jupiter in July 1994. The impact sites, located in the planet's Southern Hemisphere, are the dark spots in the upper left of the photograph.

The solar system's largest planet has some "new" neighbors.

Astronomers have discovered 12 additional moons in orbit around Jupiter, bringing the total to 79, the most of any planet in the solar system, a new study found.

The moons were discovered while astronomers were searching for objects at the edge of the solar system, according to Scott Sheppard, a scientist at the Carnegie Institution for Science who co-authored the study.

“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,” Sheppard said.

One of the objects they were looking for is the mysterious "Planet X" or "Planet Nine," which remains undiscovered.

The discovery of the new moons was reported Tuesday in the Minor Planet Electronic Circular, a publication of the International Astronomical Union.

Researchers say the new Jupiter moons weren’t seen before because they are tiny – the biggest ones are only about two miles across.

One of the newly discovered moons is an "oddball," Sheppard said. "It has an orbit like no other known Jovian moon,” he explained. It orbits in an opposite direction from the other moons near it, meaning head-on collisions are much more likely to occur.

“This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.

“It’s also likely Jupiter’s smallest known moon, being less than one kilometer (0.6 mile) in diameter."

Telescopes in Chile, Hawaii and Arizona were used for the original discovery and year-long confirmation of the moons.

“It takes several observations to confirm an object actually orbits around Jupiter,” said Gareth Williams of the International Astronomical Union’s Minor Planet Center. “So, the whole process took a year.”

Legendary Italian scientist Galileo first detected Jupiter’s four largest moons, Io, Europa, Ganymede and Callisto in 1610.</s>Astronomers have discovered a dozen new moons orbiting Jupiter, but one could spell disaster for the others - 1km-wide "oddball" moving in the opposite direction to the other 78 objects circling the gas giant.A team led by Scott S. Sheppard from Washington DC's Carnegie Institution for Science first spotted the moons in 2017 while on the hunt for a possible massive planet beyond Pluto. Sheppard's discovery brought the total number of objects orbiting Jupiter to 79 - but he said one discovery stood out in particular."This is an unstable situation," said Sheppard. "Head-on collisions would quickly break apart and grind the objects down to dust."The team at the Carnegie Institution think that the oddball moon - potentially to be named Valetudo, after the Roman god Jupiter's great-granddaughter - may represent the leftovers of a former larger moon.Gareth Williams at the International Astronomical Union's Minor Planet Center used the team's observations to calculate orbits for the newly-found moons. "It takes several observations to confirm an object actually orbits around Jupiter," Williams said. "So, the whole process took a year."</s>This Hubble telescope image of the giant planet Jupiter reveals the impact sites of two fragments from comet Shoemaker-Levy 9. Twenty-one large chunks of the comet rained down upon Jupiter in July 1994. The impact sites, located in the planet's Southern Hemisphere, are the dark spots in the upper left of the photograph.

The solar system's largest planet has some "new" neighbors.

Astronomers have discovered 12 additional moons in orbit around Jupiter, bringing the total to 79, the most of any planet in the solar system, a new study found.

The moons were discovered while astronomers were searching for objects at the edge of the solar system, according to Scott Sheppard, a scientist at the Carnegie Institution for Science who co-authored the study.

“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,” Sheppard said.

One of the objects they were looking for is the mysterious "Planet X" or "Planet Nine," which remains undiscovered.

The discovery of the new moons was reported Tuesday in the Minor Planet Electronic Circular, a publication of the International Astronomical Union.

Researchers say the new Jupiter moons weren’t seen before because they are tiny – the biggest ones are only about two miles across.

One of the newly discovered moons is an "oddball," Sheppard said. "It has an orbit like no other known Jovian moon,” he explained. It orbits in an opposite direction from the other moons near it, meaning head-on collisions are much more likely to occur.

“This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.

“It’s also likely Jupiter’s smallest known moon, being less than one kilometer (0.6 mile) in diameter."

Telescopes in Chile, Hawaii and Arizona were used for the original discovery and year-long confirmation of the moons.

“It takes several observations to confirm an object actually orbits around Jupiter,” said Gareth Williams of the International Astronomical Union’s Minor Planet Center. “So, the whole process took a year.”

Legendary Italian scientist Galileo first detected Jupiter’s four largest moons, Io, Europa, Ganymede and Callisto in 1610.</s>The solar system's largest planet has some "new" neighbors.

Astronomers have discovered 12 additional moons orbiting Jupiter, bringing the total to 79, the most of any planet in the solar system, a new study found.

The moons were discovered while astronomers were searching for objects at the edge of the solar system, according to Scott Sheppard, a scientist at the Carnegie Institution for Science who co-authored the study.

“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,” Sheppard said.

One of the objects they were looking for is the mysterious "Planet X" or "Planet Nine," which remains undiscovered.

The discovery of the new moons was reported Tuesday in the Minor Planet Electronic Circular, a publication of the International Astronomical Union.

Researchers say the new Jupiter moons weren’t seen before because they are tiny – the biggest ones are only about two miles across.

One of the newly discovered moons is an "oddball," Sheppard said. "It has an orbit like no other known Jovian moon,” he explained. It orbits in an opposite direction from the other moons near it, meaning head-on collisions are much more likely to occur.

“This is an unstable situation,” said Sheppard. “Head-on collisions would quickly break apart and grind the objects down to dust.

“It’s also likely Jupiter’s smallest known moon, being less than one kilometer (0.6 mile) in diameter."

Telescopes in Chile, Hawaii and Arizona were used for the original discovery and year-long confirmation of the moons.

“It takes several observations to confirm an object actually orbits around Jupiter,” said Gareth Williams of the International Astronomical Union’s Minor Planet Center. “So, the whole process took a year.”

Legendary Italian scientist Galileo first detected Jupiter’s four largest moons, Io, Europa, Ganymede and Callisto in 1610.</s>One of a dozen new moons discovered around Jupiter is circling the planet on a suicide orbit that will inevitably lead to its violent destruction, astronomers say.

Researchers in the US stumbled upon the new moons while hunting for a mysterious ninth planet that is postulated to lurk far beyond the orbit of Neptune, the most distant planet in the solar system.



The team first glimpsed the moons in March last year from the Cerro Tololo Inter-American Observatory in Chile, but needed more than a year to confirm that the bodies were locked in orbit around the gas giant. “It was a long process,” said Scott Sheppard, who led the effort at the Carnegie Institution for Science in Washington DC.



Jupiter, the largest planet in the solar system, was hardly short of moons before the latest findings. The fresh haul of natural satellites brings the total number of Jovian moons to 79, more than are known to circle any other planet in our cosmic neighbourhood.



Nine of the new moons belong to an outer group that orbit Jupiter in retrograde, meaning they travel in the opposite direction to the planet’s spin. They are thought to be the remnants of larger parent bodies that were broken apart in collisions with asteroids, comets and other moons. Each takes about two years to circle the planet.



Two more of the moons are in a group that circle much closer to the planet in prograde orbits which travel in the same direction as Jupiter’s spin. Most likely to be pieces of a once larger moon that was broken up in orbit, they take nearly a year to complete a lap around Jupiter. Which direction the moons swing around the planet depends on how they were first captured by Jupiter’s gravitational field.

Astronomers describe the twelfth new Jovian moon as an “oddball”. Less than a kilometre wide, the tiny body circles Jupiter on a prograde orbit but at a distance that means it crosses the path of other moons hurtling towards it. Scientists have named the new moon Valetudo after the Roman god Jupiter’s great-granddaughter, the goddess of health and hygiene. But given the impending violence, it may be more than coincidence that Vale Tudo, which translates from Portuguese as “anything goes”, is an early form of full-contact mixed martial arts. 



“Valetudo is like driving down the highway on the wrong side of the road,” said Sheppard. “It is moving prograde while all the other objects at a similar distance from Jupiter are moving retrograde. Thus head-on collisions are likely.”



Sheppard, whose report appears in the International Astronomical Union Minor Planet Electronic Circular, suspects that Valetudo is the final remnant of a once much larger moon that has been ground to dust by collisions in the past.

Which raises the question of how long the tiny moon has left. “Collisions don’t happen all that frequently, every billion years or so,” said Sheppard. “If one did happen, we would be able to detect it from Earth, but it is unlikely to happen anytime soon.”
Astronomers discover a giant gaseous planet orbiting a pair of brown dwarfs.