About 80 AUs diameter Orbits mostly circular, except for Mercury and Pluto. See eccentricity chart . All planets orbit counter-clockwise as seen from above Earth's North Pole. All planets except Mercury and Pluto have orbits in nearly the same plane. Mercury orbit is tilted by 7 degrees, Pluto's orbit tilted 17 degrees .
Earth is full of basins and craters that came from being struck by asteroids.
Erosion has erased most evidence. The tail always points away from the Sun because of the Solar Wind. We can see a few per night on average. This is caused by friction heating the air molecules in Earth's atmosphere. The air molecules are put into an excited state and release that energy in the form of visible light as they relax to ground state.