By EOY 2100, will humanity have sent a probe to another star system and received meaningful info?
Prediction market on manifold. I mean something like "the probe near the destination sends information about that star system and humanity receives it". I'll use my judgement to decide what counts. See also (https://manifold.markets/embed/wadimiusz/by-eoy-2050-will-humanity-have-sent#P9ZKM8ZAIG8iBKsHIcF4)
Liquidity: $1,000. Resolves: 12/31/2100.