Two exoplanets disappear

The uncertainty of science: Two exoplanets orbiting Gliese 581, both thought to be in the habitable zone, have now been proven to not even exist.

“We’ve proven that some of the controversial signals from Gliese 581 don’t come from two proposed Goldilocks planets, but instead are coming from activity within the star itself masquerading as planets,” lead study author Paul Robertson, an astronomer at Pennsylvania State University in University Park, told Space.com.

This result should serve as a strong reminder: Though it is likely that many if not most of the so far discovered exoplanets are real, it is also likely that many will turn out to be false positives. We won’t have solid real knowledge about them until we can actually get a close look at them, which will require far better telescopes in space, and maybe even interstellar missions to them.

A targeted SETI observation of Gliese 581, the nearest star with exoplanets in the habitable zone, has found no evidence of alien communications.

Radio silence: A targeted SETI observation of Gliese 581, the nearest star with exoplanets in the habitable zone, has found no evidence of alien communications.

This was a proof of concept experiment, and though they detected nothing, they also did not rule out the possibility of alien life, as their radio telescope wasn’t sensitive enough to do so. You can download the actual paper here.