Biology, History, and Differences From Earth
What’s known
Mars’ biology and history
It was recently proven that Mars used to have running water, and though it doesn’t now, scientists are trying to find ways to liquify the 5 million cubic kilometers of ice. Additionally, that orange color on the surface is due to the rusting of metals, meaning Mars contains plenty of iron.
Mars’ size
Mars’ radius is approximately 3400km, making it half the size of Earth. Mars’ days are different due to it being further from the sun: instead of 24 hour days, there are about 37 more minutes each day.
Differences
Mars’ atmosphere is drastically different from Earth: Earth is about 78% Nitrogen, 21% Oxygen, and the other 1% is every other element in the atmosphere, whereas Mars is about 97% Carbon Dioxide, 2% Nitrogen, and everything else is that remaining 1%.