Aided by the Hubble Space Telescope, astronomers said Wednesday they have found evidence of the first known moon outside the solar system, according to NASA.

>> Read more trending news

The first "exomoon" is as large as Neptune and is more than 8,000 light years away from Earth. It is located in the Cygnus constellation and orbits a gas-giant planet that revolves around a star called Kepler 1625, NASA said.

The study team cautioned that more confirmation is needed, Science magazine reported.

“This intriguing finding shows how NASA’s missions work together to uncover incredible mysteries in our cosmos,” said Thomas Zurbuchen, associate administrator of NASA’s Science Mission Directorate in Washington. “If confirmed, this finding could completely shake up our understanding of how moons are formed and what they can be made of.”

While searching for exomoons, Columbia University astronomers Alex Teachey and David Kipping analyzed data from 284 Kepler-discovered planets, NASA said. The researchers found an example in planet Kepler-1625b that suggested the presence of a moon.

“We saw little deviations and wobbles in the light curve that caught our attention,” Kipping said.

The astronomers hope to make more observations on the possible exomoon in May and have requested time on the Hubble telescope, Science reported.

"It's exciting to see the hunt for the first exomoon continue, and with what would be a shockingly large moon," Sara Seager, an astrophysicist at the Massachusetts Institute Technology, wrote in an email to Science.