2 ms·

They could be as close as 4.2 light years away: https://www.space.com/proxima-b-alien-planet-earth-sized-espresso.html https://www.space.com/proxima-b-alien-pla

• happytoexplain 6y ago
  What's more, if they were already traveling through interstellar space before deciding to come this way, they could be anywhere, I suppose.
• bluGill 6y ago
  Sure, but the number of possible stars within 100 light years is pretty small. The argument that there must be life all rest on the total number of stars within the universe, but the relevant life to humans communication needs to be within 10 light years (even then a 20 year round trip gives good odds we have figured out the answer to our question before we get their reply)