DART to strike asteroid Monday in Earth-defense test

DART will reach the double asteroid system Didymos A and B tomorrow. It’ll steer itself into the smaller asteroid at a speed of about 4 miles per second (6.6 km/s). Just before it strikes the asteroid, it’ll transmit back to Earth a closeup of Didymos B’s surface features … and then nothing. Meanwhile, a 2nd craft – the Italian Space Agency’s LICIACube, which has already separated from the DART mothership, will let the world witness the event. Image via ESA/ NASA/ Johns Hopkins APL/ Steve Gribben.

DART zeros in on an asteroid

DART – the Double Asteroid Redirect Test – is zeroing in on its target. DART is the first real test of our ability to defend ourselves from an asteroid on a collision course with Earth. For this test, DART is targeting Didymos B – aka Dimorphos – a little asteroid moon that’s just 525 feet (160 m) in diameter. It’ll strike the little asteroid – hoping to nudge it slightly off-orbit – at 7:15 p.m. EDT (23:15 UTC) on September 26, 2022.

This test will show if we’re ready to take on any threatening asteroids that could be headed our way.

Earlier this month, NASA reported that DART had its first look at its target, the asteroid system Didymos and its moon Dimorphos (or Didymos B), back in July. The LICIACube spacecraft, which will witness the impact, successfully separated from DART on September 11.

How to watch the impact

If you want to watch the event live, coverage begins at 6 p.m. EDT (22 UTC) on September 26, 2022, on NASA’s website. You can also watch it via Facebook, Twitter and YouTube.

View larger. | DART got its 1st look at the asteroid Didymos back in July 2022. The mission is on target to impact Didymos’s moonlet Dimorphos on September 26, 2022. Image via NASA/ JPL/ DART Navigation Team.

The DART mission is only a test

Didymos B poses no threat to Earth. This little moonlet and its parent asteroid orbit the sun in an elliptical path that brings them close to Earth and then out past the orbit of Mars. Didymos B is the size of a typical asteroid that might threaten Earth. If DART is successful, it will be the world’s first test of technology to defend Earth against threats of an asteroid on a collision path with our world. As NASA said:

This test will show that 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. DART will provide important data to help better prepare for an asteroid that might pose an impact hazard to Earth, should one ever be discovered.

When the impact occurs, Italy’s LICIACube will be watching. LICIACube – or the Light Italian Cubesat for Imaging of Asteroids – is part of the DART mission and successfully separated from DART on September 11. The little spacecraft will be studying the impact plume, measuring the impact site and observing the non-impacted hemisphere as well.

You can learn much more about the DART mission, Didymos B, and any meteors that might result from the impact here.

Bottom line: The DART mission to impact and try to move an asteroid for the first time will occur on September 26, 2022, at 7:14 p.m. EDT. It’s the first real test of our ability to defend ourselves from an asteroid on a collision course with Earth.

September 25, 2022

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Kelly Kizer Whitt

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