Exploratour: NASA's Exploration for Life

Corel Photography

Where might we find extraterrestrial life in the solar system, and in what ways might an habitable place be different from Earth?
  • Warmth?
    • It seems that the temperature on Earth (room temperature, so to speak) is just right for life. More importantly, chemical reactions take place at just the right speed in temperature ranges found on Earth. The speed at which chemical reactions take place is relevant to the formation and existence of life; freezing temperatures are OK, reactions take a longer time, and blisteringly hot (oven temperatures) are also suitable for chemistry, but really extreme temperatures such as -300 F or 5000 F won't work. Thus an habitable planet can't be too cold or life wont be abe to get started. Billions of years might pass before the relevant chemicals are exchanged because the chemical reactions take too long. And a planet can't be too hot or molecules wont stay together long enough to form solid matter.
  • Oxygen?
    • seems to be essential for life
  • Water?
    • water is a source of oxygen
  • Protection from Ultra Violet rays
    • Ultra Violet light breaks molecules apart
Thus we might expect to find life on planets like our own which are near the Sun. Planets such as Mars or Venus. Another suitable place might be in the atmosphere of Jupiter or the other outer planets where the temperatures are a toasty 80 degrees or so. For a clearer idea of what to look for, we must start with a clear idea of what life is. At least life as we know it on Earth.

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