Will An Asteroid Hit Earth? NASA To Launch Planetary Defense Mission

NASA on Wednesday will launch the world’s first planetary defense mission, which could protect Earth from a potential asteroid collision.

The $325 million Double Asteroid Redirection Test (DART) mission is set to intentionally crash a spacecraft into the asteroid Dimorphos and change its orbit as a way to deflect its path from Earth.

The joint mission with the Johns Hopkins Applied Physics Laboratory is scheduled to launch Wednesday at 1:21 a.m. ET from Vandenberg Space Force Base in California.

The spacecraft will ride into orbit atop a SpaceX Falcon 9 rocket, NBC News noted.

Nancy Chabot, a planetary scientist at Johns Hopkins University and the mission's coordination lead, said the spacecraft will crash into Dimorphos next fall at a speed of 15,000 mph.

"This isn't going to destroy the asteroid — it's just going to give it a small nudge," she said earlier this month in a news briefing. "It's actually going to deflect its path around the larger asteroid, so we're demonstrating asteroid deflection in this double asteroid system."

At 525 feet wide, Dimorphos is about the size of the Great Pyramid of Giza. It is a moon to the larger asteroid Didymos and completes an orbit of its parent rock once every 11.9 hours, The Guardian reported.

"If one day an asteroid is discovered on a collision course with Earth, then we will have an idea how much momentum we need to make that asteroid miss the Earth," Andy Cheng, DART investigation team lead at the Johns Hopkins Applied Physics Lab, told CNN.

Neither Dimorphos nor Didymos have a significant chance of colliding into Earth over the next 100 years, according to NASA. The agency is conducting the test as a training measure so that the agency knows how to respond if a collision was projected.

"It's very rare for an asteroid to impact the Earth," Lindley Johnson, a planetary defense officer at NASA headquarters in Washington, D.C., told NBC News, "but it's something we want to know about well ahead of time."

DART is part of a one-year, two-part mission called the Asteroid Impact and Deflection Assessment. The second part will be developed by the European Space Agency’s Hera mission set to launch in 2024 to conduct a more detailed investigation of the Didymos system and the DART probe's deflection capabilities.