When the first exoplanet—or planet orbiting another star—was discovered in 1992, it was a very big deal. Today, we've discovered thousands of exoplanets and it takes a particularly noteworthy one to grab our attention. We've spotted big exoplanets, small exoplanets, and everything in between.

Now scientists are moving on to the next big thing: exomoons. Researchers examining old data from the Kepler Space Telescope have spotted what they believe is the first-ever moon beyond our solar system to be found, and they're planning to use the Hubble Space Telescope to confirm it.

As you might have guessed, the exomoon is an enormous one. The planet in question is Jupiter-sized, and the moon—if it indeed exists—is around the same size as Neptune. The Kepler telescope observed the planet and its moon passing in front of their star, which caused the star's brightness to dip slightly.

This exoplanet-exomoon pair is a strange one, and looks nothing like anything in our own solar system. The researchers believe that the larger, Jupiter-sized planet captured the smaller one and turned it from planet into moon. Unfortunately, the observations from Kepler aren't clear enough for the scientists to say definitively that the moon exists. That's why they need to use Hubble to take a second look. If Hubble confirms the moon's existence, it will be the first exomoon ever found.

With the many highly sensitive telescopes scheduled to be completed in the next few years, more exomoon discoveries are almost certain. We'll probably find a few really big moons over the next few years, and as our telescopes get better we might start finding moons that look like our own.

Pretty soon, exomoons will be old news too, so enjoy this discovery while it's still fresh.

Source: New Scientist

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Avery Thompson
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