Astronomers have successfully spotted what they believe is the very first moon outside of our solar system.
More than 3,000 exoplanets – worlds orbiting stars other than the Sun – have been found so far.
However, finding moons that orbit around these distant exoplanets has been a challenge for experts for years.
Now, a couple of astronomers claim to have found compelling evidence of the existence of a moon the size of Neptune orbiting the exoplanet Kepler-1625, located around 8,000 light-years away from Earth.
It is the first exomoon discovered to date, and its size is bewildering.
The discovery was presented in a study published in the journal Science Advances.
Scientists combed through data from 284 exoplanets spotted by the Kepler Telescope, that orbit their host star in around 30 days.
After studying the data obtained from the planet Kepler-1625b, the team of researchers noticed anomalies in the data.
“We saw little deviations and wobbles in the light curve that caught our attention,” Dr. Kipping, one of the studies authors said.
To verify the data obtained by Kepe, the team of researchers secured a 40-hour window to use the Hubble Telescope, which is up to three times more precise than Keplar.
This allowed them to study the potential exomoon in great detail.
Eventually, the team observed a 19-hour journey of the planet as it orbited its host star. After three and a half hours after the completion of the event, scientists noticed a smaller dip int he stars brightness which seems to indicate that another, much smaller object had crossed in front of the star.
This smaller object, astronomers believe, is the planet’s moon following slightly behind the massive planet.
Scientists say that this smaller dip is consistent with “a moon trailing the planet like a dog following its owner on a leash,” Kipping said. “Unfortunately, the scheduled Hubble observations ended before the complete transit of the moon could be measured.”
Furthermore, experts say that their observations with the Hubble Telescope allowed them to find supporting evidnece for the moon hypothesis as they found that the planet began its transit 75 minutes earlier than predicted. This, they say, supports the idea that the planet and moon are orbiting a common center of gravity, causing the planet to wobble from its predicted location.
Dr. Kipping added: “An extraterrestrial civilization watching the Earth and Moon transit the Sun would note similar anomalies in the timing of Earth’s transit.”
See the Full Study: Evidence for a Large Exomoon Orbiting Kepler-1625b