2007-08-08 14:19:50 · 9 answers · asked by melanie b 1 in Science & Mathematics ➔ Astronomy & Space
As far as we know, only one - the Earth. All other planets have an atmosphere and weather conditions totally unsuitable for humans or any life as we know it.
2007-08-08 14:24:06 · answer #1 · answered by crrllpm 7 · 1⤊ 0⤋
1
2007-08-12 14:51:23 · answer #2 · answered by Anonymous · 0⤊ 0⤋
Only one planet in the solar system can sustain human life, and that's Earth.
2007-08-08 21:34:50 · answer #3 · answered by Tuhjay 2 · 0⤊ 0⤋
Only one in our system: earth.
Mercury: too hot, no atmosphere
Venus: too hot, too much atmosphere
Earth: Like Goldilocks says... just right!
Mars: Usually too cold, not enough atmosphere
Jupiter, Saturn, Uranus, Neptune: Too much gravity, poison gas atmospheres
Pluto: Not technically a planet anymore, but too cold anyway.
None of the planets' moons can sustain human life either.
But as for the rest of the universe, there's gotta be more!
2007-08-08 21:27:01 · answer #4 · answered by Sam84 5 · 3⤊ 0⤋
If you mean being able to walk around without any support equipment (like a spacesuit) and grow food. One, Earth. Now, how many planets could we physically live on with special shelters and space suits? Probably 2, not counting moons... Earth and Mars.
2007-08-08 21:25:16 · answer #5 · answered by JimGeek 4 · 0⤊ 0⤋
Earth is the only one we really know of.
But it's hard to believe that there are not others in this vast universe. We just have not discovered them yet.
Stay tuned.
2007-08-08 21:24:08 · answer #6 · answered by s a v v y__44 3 · 0⤊ 0⤋
in ours 1, in all systems 1000's.
2007-08-08 21:36:29 · answer #7 · answered by Anonymous · 0⤊ 0⤋
1, earth
2007-08-08 21:24:39 · answer #8 · answered by John S 5 · 0⤊ 0⤋
Only earth that we know of
2007-08-08 21:26:09 · answer #9 · answered by afriprince2 2 · 0⤊ 0⤋