2006-12-01 10:02:13 · 4 answers · asked by rascal 2 in Science & Mathematics ➔ Astronomy & Space
I can only think of two anyway:
1) an artificial signal or disturbance in the electromagnetic spectrum, and
2) a visit to our solar system by manned or unmanned craft that we know we didn't build.
By "signal", I mean something intentional. By "disturbance", I mean something that might be a by-product of some other activity.
2006-12-01 10:10:11 · answer #1 · answered by Otis F 7 · 3⤊ 0⤋
Radio wave throughout the outer space. The Radio Telescope in Arrecibo, Puerto Rico is already doing that.
Analysing the chemical composition of celestial bodies. i.e. surface of Titan or Mars.
2006-12-01 10:38:54 · answer #2 · answered by Odio a los Estados Unidos! 5 · 0⤊ 0⤋
Two methods currently used are 1) scan radio waves for non-natural signals, and 2) scan for very short pulses of laser light, which would also require an artificial source.
2006-12-01 21:11:18 · answer #3 · answered by SAN 5 · 0⤊ 0⤋
Eyes and ears
2006-12-01 10:10:24 · answer #4 · answered by Susan M 7 · 0⤊ 0⤋