About 50000 years ago, a 130 feet wide asteroid coming from space collided with Earth and created a big hole in northern Arizona. This 570 feet deep hole covers around 4100 feet area. According to recent study, the speed of asteroid during collision was around 34000 mph (15 km/sec) which is 10 times more than a rifle bullet.
The speed was calculated based on large meteors’ speeds in relation to Earth. During this collision, huge amount of melted rock would have produced in and around the crater, according to researchers.
Our atmosphere is composed of dust and has various layers that can obstruct or create resistance for foreign elements coming from space towards Earth. These would also have created obstruction or resistance for the asteroid while entering the atmosphere, resulting to breaking some portions of the space rock into small pieces of iron cloud before it hit the planet. It was revealed using a new computer model. Even these obstructions, about half the original size of asteroid remained unbroken. Meteor Crater has now become a famous tourist spot.
In 1908, this type of incident had also occurred in Siberia, but it was exploded above the ground which destroyed hundreds of miles of forest. No extraterrestrial trace was found on the ground zero.
"Earth's atmosphere is an effective but selective screen that prevents smaller meteoroids from hitting Earth's surface," Melosh explained.
"Even though iron is very strong, the meteorite had probably been cracked from collisions in space," Melosh said. "The weakened pieces began to come apart and shower down from about 8.5 miles (14 kilometers) high. And as they came apart, atmospheric drag slowed them down, increasing the forces that crushed them so that they crumbled and slowed more."
Source:
https://www.space.com/834-mystery-arizona-meteor-crater-solved.html
https://www.lpi.usra.edu/science/kring/epo_web/impact_cratering/enviropages/Barringer/barringerstartpage.html