(CNN) – Astronomers may have discovered a moon unlike anything in our solar system.
It is the second space object to be discovered outside our solar system that may be an exomon or moon. Kepler 1708b, a giant moon orbiting Jupiter, was discovered 5,500 light-years from Earth.
A study describing these findings was published in the journal Thursday Natural astronomy.
The newly discovered celestial body is 2.6 times larger than Earth. There is no analogy to such a large moon in our own system. For reference, our own moon is 3.7 times smaller than Earth.
This is the second time that David Kipping, an assistant professor of astronomy and head of the Cool World’s Laboratory at Columbia University, and his team have found an Exomune candidate. They first discovered a Neptune-sized moon orbiting a giant exoplanet called Kepler-1625b. In 2018.
“Astronomers have so far identified more than 10,000 exoplanet candidates, but the exomunions are the most challenging,” Kipping said in a statement. “They are terra incognito” (unknown land). “
A better understanding of the moons — for example, how they form, whether they can support life, and whether they play a role in the planet’s potential viability — will lead to a greater understanding of how planetary systems are formed and formed.
Items are hard to find
Kipping and his team are still working to confirm that the first candidate they discovered was in fact an exomune, and this latest finding could face the same upward battle.
Moons are common in our solar system, which has more than 200 natural satellites, but a long search for galaxies has often failed. Astronomers have succeeded in finding extraterrestrials around stars outside our solar system, but exomons are very difficult to identify due to their small size.
4,000 confirmed asteroids have been found throughout the galaxy, but that does not mean they are easy to find. Many of them were detected using the transit method or by searching for a planet to sink in stellar light as it passed in front of its star. The moons are small and very difficult to make small tips in the starlight.
To find this second possible moon, Kipping and his team explored telescopic cold-gas giant exoplanets using data from NASA’s retired planet-hunter Kepler mission. Researchers have used this criterion in their search because in our solar system, the gas giants Jupiter and Saturn have the largest number of moons orbiting them.
Of the 70 planets they explored, only one expressed a sub-signal that appeared to be the Moon, which has only a 1% chance of being something else.
“This is a stubborn sign,” Kipping said. “In this case we threw the kitchen sink, but it’s not going to.”
3 ways the moon is formed
The newly discovered candidate shares a resemblance to the first possible exomune discovery. Both may be gaseous, which explains their enormous size, and they are far from their host stars.
There are three main theories about how moons form. For one, the split object becomes the moon when large space objects collide. Another capture is believed to be a captured Khyber belt object, when objects orbiting a large planet like Neptune’s moon Triton were captured and placed in orbit. Third, moons formed from gas and dust-like objects orbiting the stars that formed the planets in the early days of the solar system.
The two exomune candidates that eventually orbited large planets such as Kepler 1625b and Kepler 1708b began to orbit.
Giant moons are probably an anomaly
Kipping thinks it is impossible for all the moons outside our solar system to be as large as these two candidates, which could produce different balls than the standard. “The first finding in any survey is usually bizarre,” he said. “Large ones that can be easily detected by our limited sensitivity.”
Follow-up observations by the Hubble Space Telescope and the James Webb Space Telescope will be required in 2023 to confirm that both candidates are exomons. Meanwhile, Kipping and his team continue to gather evidence in support of the Exomoons.
The fact that each associated planet takes more than an Earth year to complete an orbit around its star slows down the discovery process.
“Lunar orbits need to be repeated several times for confirmation,” Kipping said. “The long-term nature of our target planets means there are only two orbits here, but not enough to see the lunar transits needed to confirm the confirmation.”
If confirmed, the fact that exomons are as common as extraterrestrials outside our solar system could be the beginning of a new acceptance.
The first asteroid was not discovered until the 1990s, and most of the asteroids known today were not revealed until Kepler’s launch in 2009.
“Those planets are alien compared to our home system,” Kipping said. “But they have revolutionized our understanding of how planetary systems form.”