Five things to know about NASA’s mission to hit an asteroid

On Monday, NASA plans to strike an asteroid about 7 million miles from Earth with a 1,000-pound spacecraft in an unprecedented planetary defense test.

If successful, the Double Asteroid Redirection Test (DART) will be the first-ever spacecraft to deflect an asteroid with a kinetic strike and adjust its speed and flight path.

Here’s what you need to know about DART, which is headed toward a collision with the asteroid Dimorphos.

NASA expects to strike Dimorphos around 7 p.m.

NASA will begin live coverage of the event around 6 p.m. ET on Monday. Video coverage will be available on NASA’s social media accounts, including its YouTube page.

DART is estimated to slam into Dimorphos around 7:14 p.m. at more than 14,000 miles per hour. NASA officials will be able to estimate the results of the strike by using ground-based telescopes.

Following the event, officials will hold a media briefing around 8 p.m. to discuss DART’s mission.

DART is a key test for future threats

NASA has repeatedly stressed that Dimorphos is not a threat to Earth, but the mission’s success is important for the space agency to develop an effective response to any future threats.

If DART is successful, it could shorten the orbital period of Dimorphos by several minutes. After the mission, NASA will apply any lessons learned to future tests designed to ward off a future asteroid from colliding with Earth.

No known asteroid larger than 140 meters in size has a significant chance to impact Earth in the next 100 years, but scientists have only found about 40 percent of those asteroids as of October 2021, according to the Johns Hopkins Applied Physics Lab (APL), a partner in the DART mission.

DART was authorized after a meteor exploded in Chelyabinsk, Russia, in 2013, creating a shockwave felt in six cities across the nation.

NASA has an entire office dedicated to defending the planet: the Planetary Defense Coordination Office.

DART launched in November

The DART spacecraft launched on Nov. 23, 2021, from a SpaceX Falcon 9 rocket out of Vandenberg Space Force Base, Calif.

The spacecraft weighs 1,345 pounds but consists of just one instrument: the Didymos Reconnaissance and Asteroid Camera for Optical navigation system, known as DRACO, which will capture images of Dimorphos and its asteroid system.

DRACO also helps direct DART’s flight toward Dimorphos with the Small-body Maneuvering Autonomous Real Time Navigation (SMART Nav), an algorithm using images from DRACO to chart a direct path.

Dimorphos is part of an asteroid system

Dimorphos is part of the binary asteroid system Didymos, which means twin in Greek. The asteroid system is about 7 million miles from Earth.

Technically, Dimorphos is a moonlet of Didymos, a larger asteroid that Dimorphous orbits in the system.

Dimorphos is 560 feet wide, weighs more than 5 billion kilograms and completes an orbit of its parent asteroid once every 11 hours and 55 minutes.

The two asteroids are about .73 miles apart.

A follow-up mission is planned

The European Space Agency (ESA) will send a spacecraft called Hera toward the Didymos asteroid system in 2024 to assess the impact of DART in greater detail.

In a report, ESA — which expects Hera to arrive at Didymos in 2026 — said the Hera spacecraft will also “provide significant insights into asteroid science and the evolutionary history of our solar system.”