Science

Possible discovery of exomoon excites astronomers, but what is it?

Possible discovery of exomoon excites astronomers, but what is it?

Astronomers using the NASA/ESA Hubble Space Telescope and NASA's Kepler Space Telescope have assembled compelling evidence for the existence of a large exomoon orbiting Kepler 1625b, a gas giant located approximately 8,000 light-years away from Earth. An ageing sun-like star in the constellation Cygnus is known to host a huge, gas giant planet the size of Jupiter, known as Kepler 1625b.

Scientists may have detected the first moon orbiting a planet in a far-off solar system, though they caution that they still want to confirm the finding with another round of telescope observations.

Our hunt for exoplanets (planets further into the cosmos) has thrown up some truly odd and fascinating examples in recent years, with confirmed discoveries now numbering in the thousands.

"This would be the first case of detecting a moon outside our solar system", said Kipping, assistant professor of astronomy at Columbia. And excitingly, some of the moons around the giant planets in our solar system - including Europa, Enceladus and Titan - are now our best bet for finding life outside our own planet (or possibly on Mars).

Teachey and co-author David Kipping, an assistant professor of astronomy at Columbia, published their findings in the journal Science Advances on October 3.

"If confirmed by follow-up 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", he added.

NELL GREENFIELDBOYCE, BYLINE: Even in our own solar system, some of the most intriguing places to hunt for life are moons, like Enceladus and Europa around Saturn and Jupiter.

Hubble also revealed that the planet began its transit 1.25 hours earlier than expected-consistent with the planet and moon orbiting a common center of gravity that would cause the globe to wobble from its predicted location. They noticed that after Kepler-1625B crossed in front of its star there was another decrease in measurable brightness 3.5 hours late.




With the help of space telescopes "Hubble" and "Kepler" researchers have determined that around the planet Kepler-1625б rotating celestial body the size of Neptune.

Kepler 1625b and its satellite, however, are gaseous, not rocky, and, therefore, such a collision may not lead to the condensation of a satellite.

Hints of a moon orbiting the planet called Kepler-1625b were first detected a year ago, but the pair used Hubble to analyse the region in greater detail.

Kipping said that's how the Earth and moon would appear from far away. "But we knew our job was to keep a level head and essentially assume it was bogus, testing every conceivable way in which the data could be tricking us". This is called a "planetary wobble" and is caused by gravitational pull of another celestial body. This moon is thought to be the size and mass of Neptune. They watched the planet during its 19-hour transit.

"To be honest, we never really anxious much about habitability, just because they're both gas giants, so it really wasn't something we spent any effort or time worrying about", Kipping said during Monday's teleconference.

The astronomers used the Hubble Space Telescope, which was built by NASA with contributions from the European Space Agency. The first drop in brightness had to be a planet passing in front of its star, while the second failure could justify the presence of ecolony outside our solar system.

"But moving forward, I think we open the door to search for such worlds", said Teachey. It seemed to show signs of a moon: Regular and periodic - and slight - dimming of the star's light after the planet transited. The research team hopes to take another look at the star next May, if there is time available on the Hubble.