Crawford and Schulze-Makuch ask a blunt question in the title of their paper in Nature Astronomy: ”Is the apparent absence of extraterrestrial technological civilizations down to the zoo hypothesis or nothing?” The zoo hypothesis posits that we are being studied by beings that for reasons of their own avoid contact. David Brin referred in his classic…

While the exact composition of these worlds remains unclear, estimates of their surface temperatures from previous studies point them being significantly colder than Earth. They’re also each less dense than Earth, despite being roughly the same size as our planet. “Our analyses predict that these 17 worlds may have ice-covered surfaces but receive enough internal heating…

The more I see a lack of success in the SETI field, the more I feel our own bio-chem chauvinism is getting the in way… Our own planet teaches us that life is weirdly untethered from our surface dwelling norms. Astrobiologists hunting for the first definitive signs of life outside of Earth often target planets…