The planet known for having large amounts of iron oxide in its soil and polar ice caps is Mars. It is known to be the second smallest planet in the solar system. It is also known as the Red Planet due to the reddish appearance of the soil which is caused by the high amounts of iron.
The planet known for being covered in cliffs and craters and having a weak magnetic field is Mercury. It is the closest to the sun and the smallest planet in the solar system.
Comets are hypothesized to come from the Oort Cloud which is located beyond the orbit of the planets.
