Mars

  Mars is the planet that has the highest possibility of having creatures. Through many expeditions, scientists have found evidence that water once existed on Mars. Some scientists think that if there was water on Mars, the second-best environment for creatures, lives could have existed on it and some of them could have moved to Earth when small pieces of Mars containing lives crushed Earth as asteroids. NASA is still searching for more evidence and traces of life.

  This information that NASA provides is very interesting. However, I have one question about the research itself, even though I'm not an expert in astronomy or something. I wonder why scientists narrow the range down to planets that have water and have "mild" temperature. Scientists don't explore Mercury because it doesn't have water and has too hot atmosphere. I think these factors for sustaining life are too "Earth-centred". "Mild" temperature for lives on Earth isn't necessarily required for extraterrestrial life, if there is one. The universe is unimaginably big, and there can be infinite possibilities of life form, such as animals that do not need oxygen and die if exposed to oxygen. There is one type of bacteria that can only survive in boiling water even on Earth.