In more conventional science fiction sagas, extraterrestrials often resemble the living beings we know. Often, they are even intelligent and walk upright on solid planets like our own. However, reality can be stranger. This is the hypothesis being pursued by the team of Cambridge University astronomer Nikku Madhusudhan, who has just announced what he calls “the strongest evidence yet” of life beyond Earth. Other experts, however, believe there is no data to support such a claim.