Formation and evolution of the Solar System impact event, the Tunguska event, the Chelyabinsk meteor and the impact feature Meteor Crater in Arizona. The process of accretion, therefore, is not complete, and may still pose a threat to life on Earth. Over the course of the Solar System's evolution, comets were ejected out of the inner Solar System by the gravity of the giant planets, and sent thousands of AU outward to form the Oort cloud, a spherical outer swarm of cometary nuclei at the farthest extent of the Sun's gravitational pull. Eventually, after about 800 million years, the gravitational disruption caused by galactic tides, passing stars
Solar eclipses on the Moon portion of the eclipse was rising. Eclipses were more frequent, tens of millions of years later, eclipses became less numerous as the lunar orbit slowly moved away from the Earth. The view of the sun, even its chromosphere was blocked by the Earth. Around some hundreds of millions of years ago, the Earth blocked all of the Sun's chromosphere, totality was slightly longer than the partial portion. At the same time there were more partial eclipses on the Moon. As the Moon recedes about 3 cm each year, eclipse totality length slowly shrinks and the partial portion slowly lengthens. The