Dr.APJAK Sir's answer...
"When I addressed Southern Regional Science Congress at Coimbatore, Tamilnadu, one student started, he said "my teacher today told me that the Sun has got eight planets, only earth has got life and life supporting system for thousands of species. Tell me Mr Kalam, why not other seven planets of our Sun not habituated.
I asked the student, what his name and in which class studying. He said, my name is Saravanan and studying in 10+2.
My answer to the student was; actually this has been question answered in beautiful way long-long ago by Isaac Newton himself, the discoverer of gravitational law. Newton said, "the only miracle is the earth at a unique distance, gets required warmth and light from the Sun".
Let me answer further to your question.
What is the environment of other planets?
I said, dear young friend,
do you know that on Jupiter,
three thousand times the size of the earth,
a powerful hurricane has been raging for the past 400 years:
on Neptune wind speeds reach up to 3200 km per hour,
that is over 10 times higher than the strongest gusts
mustered by Katrina, USA or Tsunami winds India's experienced.
On Mars, the dust stormed continuously engulfs part of the planet.
On Saturn's Moon Titan it rains liquid methane and
Venus is chocked by a thick smoggy blanket of sulfuric acid.
Is any species, possible such an environment?
Scientific debates going on...,
none of these happen on our planet earth
and we are safe."