First exomoon found? Astronomers optimistic but urge caution

Artist’s conception of a large Earth-like exomoon orbiting a giant gaseous exoplanet. Image Credit: Avatar/20th Century Fox

Exoplanets are being found so frequently now that they have become commonplace. But what about exomoons? As might be expected, they are much harder to detect, being typically much smaller than most planets. There have been tantalizing hints but nothing conclusive so far. That may be about to change soon, however. Astronomers from Columbia University have reported the possible discovery of the first exomoon – but they stress that it is still unconfirmed and just a candidate at this point.

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Bizarre Boyajian’s Star (‘alien megastructure’ star) is dipping again!

Artist’s concept of Boyajian’s Star with a huge swarm of comets. Image Credit: NASA/JPL-Caltech

The weird star called Boyajian’s Star (aka Tabby’s Star or KIC 8462852) has been fascinating astronomers and people in general because of its weird behaviour of experiencing sudden, unusual dips in brightness which all current theories have so far had difficulty explaining. Now, the star has started dipping again after a long period of “normal” activity.

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NASA’s Kepler Space Telescope continues observations of TRAPPIST-1 planetary system

Artist’s conception of some of the planets in the TRAPPIST-1 planetary system. Image by ESO/M. Kornmesser/N. Risinger (skysurvey.org)

The seven Earth-sized exoplanets orbiting the star TRAPPIST-1 generated a lot of excitement when their discovery was announced last month. This is the largest collection of Earth-sized worlds in one planetary system found so far, and some of them are well within the star’s “habitable zone” where temperatures could allow liquid water to exist on their surfaces. Little else is known about the actual conditions on these planets so far, but NASA’s Kepler Space Telescope has also been observing TRAPPIST-1 in recent weeks.

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