C134.txt

The first thing we filtered out is
Gravity:
Mercury - 3.7m/s
Venus - 8.87m/s
Earth - 9.8m/s
Mars - 3.8m/s


Now if we talk about their position in the solar system; (0.38 to 2 AU),
Mercury - 0.4AU
Venus - 0.7AU
Earth - 1AU
Mars - 1.5AU
This again, makes all these planets lie in the Goldilock zone!


Now, if we talk about the speed of
these planets, our final filter then:
Mercury - 47km/s
Venus - 35km/s
Earth - 30km/s
Mars - 24km/s
Again, this makes all these planets habitable!

Mercury -
Mercury is not habitable since it does not have an atmosphere and its
temperature varies from 100 Degree Celsius to 700 Degree Celsius.

Venus - Venus is an extreme planet and it’s very hot. It’s atmosphere 
traps the heat on the surface and its temperature is a whopping 700
Degree Celsius. There are also rains of sulphuric acid.

Earth - Seems like just the right planet to exist.

Mars - Mars has some atmosphere and it also has water on its surface. 
The temperatures are a bit extreme (20 Degree to -150 degree) but it is 
still manageable compared to others.