Nature celebrates (sort of) a discovery that makes it just a smidge more likely that there’s life somewhere else out there – a little blip that probably means there’s a moon orbiting a faraway planet just like ours orbits Earth:
On a June night two years ago, a telescope in New Zealand captured a momentary brightening of a star in the constellation Sagittarius. It was an occurence of a rare phenomenon known as microlensing, in which a star or planet or other celestial object passes directly between Earth and a more distant star, gravitationally magnifying the light of the faraway star.
After sifting through detailed observations of this event, astronomers proposed that the intervening object could be either a smallish star with a Neptune-sized planet orbiting it, or a largish planet with a moon orbiting it.
If the latter possibility is confirmed, it would be the first ever detection of an exomoon. The problem is that there is no way to repeat the observation and know for sure.
“It’s kind of a shame because we’ll probably never know what the answer is,” says David Kipping, an astronomer at the Harvard?Smithsonian Center for Astrophysics in Cambridge, Massachusetts, who was not involved in the research.