Distance from the center of the Sun to the object at the time of discovery (so visiting asteroid or spacecraft counts).
Life transported from AND originating on Earth does not count.
The close date will be extended if needed.
Resolves YES on conclusive evidence, NO once the solar vicinity has been throughly explored and understood.
Inspired by the markets created by @RemNi e.g. /RemNi/will-we-discover-alien-life-before-939ead04dfb1
1,000
3.00Per https://en.wikipedia.org/wiki/List_of_nearest_stars_and_brown_dwarfs#List there are exactly fifteen stars within 10 light years of the solar system (at least to our knowledge):
the Sun (duh!)
the three stars of Alpha Centauri, all sun-like
Barnard's Star, a red dwarf
Luhman 16, which consists of two stars, both brown dwarf
WISE 0855−0714, a brown dwarf
Wolf 359, a red dwarf
Lalande 21185, a red dwarf
Sirius, which consists of two stars
Gliese 65, which consists of two stars
So if we can enumerate all the planets of these 15 stars and check each one for biosignatures, we'll be done.