By Elton Gomes
It appears that astronomers have found the first moon detected outside our solar system. The exomoon is a large gaseous body the size of Neptune and is known to orbit a gas planet that is much larger than Jupiter.
Astronomers found the exomoon on October 3, and were amazed at how different this moon was from the roughly 180 known in our solar system.
What are exomoons?
Exomoons are the natural satellites of planets orbiting stars outside our solar system. There have not been any confirmed examples of exomoons till date. Researchers from Columbia University said that such large moons do not exist in our solar system, where almost 200 natural satellites have been found.
What does the study say?
According to the study, which has been published in Science Advances, the exomoon that has been found is unusual due to its large size. Its size can be compared to that of Neptune. However, researchers have said that the moon hypothesis is tentative and that it must be confirmed by follow-up Hubble observations.
“This would be the first case of detecting a moon outside our solar system,” said David Kipping, an assistant professor of astronomy at Columbia University, PTI reported.
Kipping added that once the finding has been confirmed, it could provide clues about planetary systems. “If confirmed by follow-up Hubble observations, the finding could provide vital clues about the development of planetary systems and may cause experts to revisit theories of how moons form around planets,” Kipping said.
The researchers analysed data from 284 planets that were discovered by Kepler. These planets were comparatively in wider orbits, with periods greater than 30 days, around their host star. The observations measured the momentary dimming of starlight as a planet passed in front of its star. The researchers found that Kepler 1625b showed some interesting observations. “We saw little deviations and wobbles in the light curve that caught our attention,” Kipping said, as per the PTI report.
“You could argue that because larger objects are easier to detect than smaller ones, this is really the lowest-hanging fruit, so it might not be wholly unexpected that the first exomoon detection would be among the largest possible,” the study’s co-author Alex Teachey said, Reuters reported.
The Kepler 1625b results were enough for the team to get 40 hours with the Hubble Telescope in order to intensively study the planet. They were able to collect data which was four times more precise than that of Kepler.
How did the moon form?
There are three theories about how moons are formed. One is when planets impact larger bodies, and the blasted-off material turns into a moon. The second theory is capture, which occurs when objects are captured and pulled into orbit around a large planet. An example of this is Neptune’s moon Triton, which is believed to be a captured Kuiper Belt object. The third theory is that moons were formed from the disc materials that created the planets in the early days of the solar system. In the current finding, the impact has been ruled out, and the moon’s size is inexplicable yet. The moon’s formation, therefore, remains a mystery.
Why is the detection of exomoons important?
According to a report in June, a new study had identified a total of 121 exoplanets that could host natural satellites that supported life. It was reported that these exomoons were situated in the habitable zone of their respective stars. Though they orbited a large gaseous planet, there was a good chance that they have liquid water on their surface.
“There are currently 175 known moons orbiting the eight planets in our Solar System. While most of these moons orbit Saturn and Jupiter, which are outside the Sun’s habitable zone, that may not be the case in other solar systems,” co-author Stephen Kane, from the University of California Riverside, said in a statement. “Including rocky exomoons in our search for life in space will greatly expand the places we can look.”
Elton Gomes is a staff writer at Qrius
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