NASA Scientist Answer: When was the last time an asteroid hit Earth?

Of those, 888 are more than a kilometer in diameter, two and a half times taller than New York’s Empire State Building.

But when was the last time an asteroid hit Earth?

According to NASA Jet Propulsion Laboratory scientist Marina Prosovic, the answer depends on your definition of being attacked by an asteroid.

Small asteroids hit Earth all the time, Prosovic said on NASA’s “We Heard NASA Scientist” program. However, due to the small size of those asteroids, they burn up in the atmosphere, so many of them do not even reach the Earth’s surface, making the impact of the rest zero and void.

NASA has named any asteroid approaching the planet 140 meters or more as a potential catastrophic asteroid (PHA) because of the risk of catastrophe to Earth.

Asteroid Chart (Credit: Wikimedia Commons)

In the last century, the most important asteroid to hit Earth was the size of a small building that flew over Russia in 2013. The asteroid has a range of 20 km. Above the ground, a large number of meteors were scattered over the Russian city of Chelyabinsk.

But, when was the last asteroid to have a major impact on our planet, leaving the craters at their height and causing massive catastrophe?

“We have to go backwards for such an event,” Prosovic replied. “Those old grooves are not easy to find.”

“Now, they may be filled with sediment or they may be at the bottom of the ocean,” he said.

Even today, however, asteroids pass over Earth unnoticed.

Aaron Reich contributed to this report.