NASA will deliberately crash a spacecraft into an asteroid in the name of planetary defense

(CNN) – A spaceship deliberately colliding with an asteroid is preparing for launch.

The DART mission, or NASA’s Double Asteroid Redirection Test, will lift off on November 24 at 1:20 a.m. (Miami time) aboard a SpaceX Falcon 9 rocket from Vandenberg Space Force Base in California.

“NASA will intentionally crash the DART spacecraft into an asteroid to see if that is an effective way to change its course, should an Earth-threatening asteroid be discovered in the future,” SpaceX said. this friday on twitter.

After launch in November, NASA will test its asteroid deflection technology in September 2022 to see how the motion of a near-Earth asteroid impacts space.

The target of this asteroid deflection technology is Dimorphos, a small moon orbiting the near-Earth asteroid Didymos. This will be the agency’s first large-scale demonstration of this type of technology on behalf of planetary defense.

In a video posted by NASA on Twitter, the space agency indicates that crashing a spacecraft into an asteroid is all that is needed in the event that an asteroid is discovered far in advance before it hits Earth. “

Why are we crashing a spacecraft into an asteroid more than 6 million miles away?

Get the details on #DARTMission, our upcoming #PlanetaryDefense test — and tune in next week for live mission coverage: https://t.co/ld8K63DeQo pic.twitter.com/AUj86TehyI

– NASA (@NASA) November 19, 2021

Didymos and Dimorphos

Two decades ago, a binary system involving a near-Earth asteroid was discovered to have a moon orbiting it. It was called Didymos. In Greek, Didymos means “twin,” which was used to describe how the larger asteroid, approximately 804 kilometers in diameter, is orbited by a smaller moon that is 160 meters in diameter. At that time, the moon was known as Didymos b.

Kleomenis Tsiganis, a planetary scientist at Aristotle University Thessaloniki and a member of the DART team, suggested that the moon be named Dimorphos.

“Dimorphos, which means ‘two shapes,’ reflects this object’s status as the first celestial body to have the ‘shape’ of its orbit significantly changed by humanity, in this case, by the DART impact,” he said. Tsiganis. “As such, it will be the first object known to humans in two very different ways, the one seen by DART before impact and the other seen by Hera of the European Space Agency, a few years later.”

In September 2022, Didymos and Dimorphos will be relatively close to Earth, 11 million kilometers from our planet. It is the perfect time for the DART mission to occur.

DART will deliberately collide with Dimorphos to change the asteroid’s course in space, according to NASA.

This collision will be recorded by LICIACube, a complementary satellite CubeSat or cube provided by the Italian Space Agency. The CubeSat will travel on DART and then deploy before impact so that it can record what happens.

“Astronomers will be able to compare ground-based telescope observations before and after DART’s kinetic impact to determine how much Dimorphos’ orbital period changed,” said Tom Statler, DART program scientist at NASA Headquarters, it’s a statement. “That is the key measurement that will tell us how the asteroid responded to our deflection effort.”

A few years after the impact, the European Space Agency’s Hera mission will conduct a follow-up investigation of Didymos and Dimorphos.

While the DART mission was developed for NASA’s Planetary Defense Coordination Office and is managed by the Johns Hopkins University Applied Physics Laboratory, the mission team will work with the Hera mission team under an international collaboration. known as Asteroid Impact and Deflection Assessment or AIDA, for its acronym in English.

“DART is a first step in the test methods for dangerous asteroid deflection,” Andrea Riley, DART program executive at NASA Headquarters, said in a statement. “Potentially dangerous asteroids are a global concern, and we are excited to work with our Italian and European colleagues to collect the most accurate data possible from this kinetic impact deflection demonstration.”

A mission of firsts

Dimorphos was chosen for this mission because its size is relative to asteroids that could pose a threat to Earth.

DART will collide with Dimorphos moving at 23,760 kilometers per hour. A camera on DART, called DRACO, and autonomous navigation software will help the spacecraft detect and collide with Dimorphos.

This rapid impact will only change the speed of Dimorphos as it orbits Didymos by 1%, which doesn’t seem like much, but it will change the moon’s orbital period by several minutes. That change can be observed and measured from telescopes on Earth. It will also be the first time humans have altered the dynamics of a solar system body in a measurable way, according to the European Space Agency.

Three years after the impact, Hera will arrive to study Dimorphos in detail, measuring the physical properties of the moon, studying the impact of the DART and studying its orbit.

This may seem like a long time to wait between impact and follow-up, but it is based on lessons learned in the past.

In July 2005, NASA’s Deep Impact spacecraft launched a 369-kilogram copper impact at a comet, Tempel 1. But the spacecraft was unable to see the crater because the impact released tons of dust and ice. However, NASA’s Stardust mission in 2011 was able to distinguish the impact: a crater almost 150 meters.

Together, the data collected by DART and Hero will contribute to planetary defense strategies, especially to understand what kind of force is needed to change the orbit of a near-Earth asteroid that can collide with our planet.