Evidence for off-Earth life before 2027?

Why we chose it

This bet lives in the shadow of three ongoing storylines rather than one specific event. First, 3I/ATLAS — the third interstellar object ever found passing through our solar system — has been the subject of Harvard astronomer Avi Loeb's insistence that it could be an alien artefact, not a comet, with a "brightness surge" and symmetrical three-pronged jet structure spotted in January 2026 reviving the debate.

But Loeb has since walked back the alien-tech theory, and the wealth of data suggests 3I/ATLAS is a massive snowball of CO2 and water ice. Second, the K2-18b hycean-world DMS story keeps collapsing: a January 2026 preprint concluded the dimethyl sulfide detection was a false alarm, and a July 2026 VLA/MeerKAT radio survey of K2-18b turned up nothing. Third, Mars Sample Return was zeroed out of the fiscal 2026 budget, killing the near-term path to confirming the Perseverance biosignature hints.

Bull case: a Breakthrough Listen / SETI announcement — Simon Holland claims two groups of astronomers are racing to publish confirmed evidence of an extraterrestrial civilization — or a surprise JWST reveal. Bear case: "evidence" is undefined, every candidate signal is imploding under peer review, and 14% already looks generous for five months of runway. Angle for a bit: Loeb refreshing arXiv at 3am while the Mars tubes sit abandoned.