Why it would be difficult for human to live on planets other the earth?

Life is impossible on planets other than the Earth because the Earth is the only planet in the solar system and in the known universe that can sustain life. In Mercury and Venus, it is too hot for life, and there is a lack of water for life, and in Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, it is too cold to sustain life. Earth is great because it is just close enough to the sun so it's not too hot, yet not too cold. It's just right. Plus we have water on the Earth, (h20), or two hydrogen molecules bonded with one oxygen molecule, but not any "real" water has been discovered on other planets, and all living things rely on the warmth of the sun and water to survive. Hope I helped!

Maxwell