Lo-Like Volcanic Moon May Have Been Discovered Orbiting Exoplanet WASP-4b

Learn how researchers may have discovered an exomoon about 635 light-years away orbiting gas giant exoplanet WASP-4b.  Credits: NASA/JPL-Caltech

Transcript

00:00A rocky, volcanic moon could be orbiting a planet more than 600 light-years from Earth.

00:08Exomoons, or moons around planets outside our solar system, are likely too small to

00:14see directly.

00:15But astronomers think volcanic exomoons could make themselves known by creating massive

00:21clouds of volcanic gas.

00:24A new study looked at a large sodium cloud discovered in 2017 near the exoplanet WASP-49b.

00:34Scientists found evidence that the cloud is not produced by the planet or the star it

00:38orbits.

00:39Instead, the motion of the cloud suggests it originated from another object, possibly

00:45a volcanic exomoon.

00:47To get to this conclusion, researchers used a telescope on Earth to observe the silhouettes

00:52of the cloud and the exoplanet as they passed in front of the star.

00:59In one observation, the researchers saw the sodium cloud moving faster than the planet

01:04and away from Earth.

01:06If the cloud was coming from the exoplanet, the scientists would expect it to move toward

01:11Earth.

01:12They think this means the cloud was coming from a different source, like an exomoon.

01:19Jupiter's moon Io also spews a volcanic cloud into space.

01:23It pumps sodium, sulfur, and other gases, creating a massive cloud a thousand times

01:29wider than Jupiter.

01:30Io has volcanoes because Jupiter's gravity squeezes the moon's interior, heating it.

01:37Scientists think WASP-49b's gravitational squeezing is likely even more intense and

01:43may eventually cause its exomoon to disintegrate.

01:47While more observations are needed to confirm the existence of this exomoon, what researchers

01:52have found is promising.