Watch NASA’s DART Mission to Crash Into an Asteroid and Defend the Earth

Nasa prepares to crash spacecraft into asteroid in ‘planetary defense test’ – live

NASA spacecraft closes in on asteroid for head-on collision

NASA's Planetary Defense Test Crashes Spacecraft into Asteroid 7 Million Miles from Earth

What to Expect If NASA’s DART Spacecraft Misses the Asteroid

During the Double Asteroid Redirection Test (DART) set for Monday, a spacecraft will collide with a 525-ft. wide asteroid called Dimorphos if all goes according to plan.

The test is in preparation for a potential need in the future to defend the planet against asteroids and comets on a collision course with Earth.

According to CBS News, there isn't an asteroid NASA knows to be larger than 459 feet across that has "significant chance" of hitting Earth in the next 100 years.

Still, the collision itself is being looked at as monumental in the "history of humankind," per NASA planetary defense officer Lindley Johnson.