In a world-first, NASA will slam a spacecraft into an asteroid to test planetary defense

NASA’s Double Asteroid Redirection Test (DART) will be the first mission to test planetary defense technology in space.

According to a NASA statement, the DART spacecraft will impact its target asteroid, Dimorphos, at 7:14 p.m. EDT on Monday, September 26. And the event will be live streamed for all to see.

While Dimorphos poses no danger to Earth, the test will allow NASA to assess whether a spacecraft impact can be used to alter the trajectory of a hypothetical hazardous asteroid on a collision course with Earth.

NASA's DART will boost Earth's planetary defense

NASA is known to livestream key moments of its big missions — it did so for the first flight of its Ingenuity Mars helicopter, and it will do the same for the upcoming launch of its moon-bound Artemis I mission, currently slated for Monday, August 29.

In anticipation of the impact of the DART spacecraft, NASA has invited press members to attend a series of events, including one at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland. APL built and now manages the DART spacecraft for NASA.

If all goes to plan, the space agency says the DART mission will "show a spacecraft can autonomously navigate to a target asteroid and intentionally collide with it to change the asteroid’s motion in a way that can be measured using ground-based telescopes." The mission will provide "important data to help better prepare for an asteroid that might pose an impact hazard to Earth, should one ever be discovered."

The DART spacecraft launched aboard a SpaceX Falcon 9 rocket at 1:21 a.m. ET on November 24 from the Vandenberg Space Force Base in California. Roughly a month later, the DART spacecraft sent back its first images from space.

How to watch the DART impact event in September

NASA says live coverage of DART's impact event will start at 6 p.m. EDT on September 26. It will air on NASA TV, live streamed 24 hours a day on NASA's YouTube channel. We will also be sure to provide live updates here at IE before and after the impact.

The impact is scheduled to occur at 7:14 p.m. EDT, according to NASA. Shortly afterward, the space agency will be able to tell if the trajectory of asteroid Dimorphos was altered significantly. Though Earth-based observatories will take primary measurements, NASA previously announced that a CubeSat developed by the Italian Space Agency, called LICIACube, will piggyback on the DART spacecraft and separate just before impact. After impact, LICIACube will perform a flyby of Dimorphos and make observations, which may be presented during NASA's press events.

Even a small trajectory change will significantly alter an asteroid's path over the course of months and years, so only a relatively small nudge is needed. Still, the DART spacecraft is making its way to Dimorphos at 15,000 mph (24,000 km/h), meaning the impact event will likely be a sight to behold — though we will be witnessing the event from six million miles (11 million km) away on Earth.