NASA’s DART mission successfully knocks asteroid off course, Earth can now defend itself

NASA’s DART mission successfully knocks asteroid off course, Earth can now defend itself

While the asteroid was of no threat to Earth, but the test demonstrated our capability to resist asteroid impact.

Asteroid moonlet Dimorphos as seen by the DART spacecraft seconds before impact | Photo: NASA/Johns Hopkins APL/Handout via Reuters

Asteroid moonlet Dimorphos as seen by the DART spacecraft seconds before impact | Photo: NASA/Johns Hopkins APL/Handout via Reuters

New Delhi: For the first time, NASA’s Double Asteroid Redirection Test or DART has successfully knocked an asteroid off its course, demonstrating its ability to defend the planet from potentially disastrous asteroid impact in the future.

Mission control at the Johns Hopkins Applied Physics Laboratory (APL) in Laurel, Maryland, announced the successful impact Tuesday — which is humanity’s first test to resist an asteroid’s impact.

“We’re embarking on a new era of humankind, an era in which we potentially have the capability to protect ourselves from something like a dangerous, hazardous asteroid impact,” said Lori Glaze, director of NASA’s Planetary Science Division. “What an amazing thing. We’ve never had that capability before.”

While Dimorphos did not pose any actual threat to Earth, the mission aimed to test the “kinetic impactor” method which will verify to what extent it is possible to redirect asteroids that might possibly threaten the planet. Using the force of kinetic energy, this crash, that took place today, might save future generations from any real threats.

As expected, the collision has slightly changed the asteroid’s motion and path in space, and has successfully given the world a viable mitigation strategy.

While further speculation from telescopic observations are underway to clearly determine the complete success of the mission, NASA has confirmed that they expect the impact to shorten Dimorphos’ orbit by about one percent or roughly 10 minutes. Over the next few weeks, Dimorphos’ orbital change will be studied along with the debris ejected from the crash.

DART slammed itself into the asteroid which was 9.6 million kilometres away at 22,500 kilometres per hour.

Roughly four years from now, the European Space Agency’s Hera project will conduct detailed surveys of both Dimorphos and asteroid Didymos, with a particular focus on the crater left by DART’s collision and a precise measurement of Dimorphos’ mass, NASA says.

“We are not aware of a single object right now threatening the Earth in the next 100 years. But there eventually will be one. We can deduce that from the geological records of our planet and even data from the Moon. We want to test this technology now so that it is ready in case we ever need it,” said Thomas Zurbuchen, the associate administrator for the
Science Mission Directorate at NASA, during a press conference on 12 September.

The most destructive celestial impact happened 65 million years ago when an asteroid with a 5 kilometer radius crashed into Earth and gave us what we know today as the Yucatán Peninsula. The impact wiped out numerous plant and animal species including dinosaurs.

In 2019, an asteroid the size of a football field, also passed by Earth closely, and another which was the size of a 747 jet came extremely close in 2021. But all these asteroids were not expected guests, they were cosmic surprises, scientists said.

This first event which could indeed go a long way in preventing something disastrous, was launched in November 2021 and has now attained fruition. The historic was live streamed on NASA TV, which is NASA’s own and also, the space agency’s YouTube channel.

“No, this is not a movie plot,” NASA Administrator Bill Nelson tweeted earlier in the day. “We’ve all seen it on movies like ‘Armageddon’, but the real-life stakes are high,” he said in a prerecorded video.

Recording the impact

While further scientific studies are currently underway, the impact will also be studied with the help of data gathered from these devices.

The spacecraft has been carrying its own mini photography device, the LICIACube (Light Italian CubeSat for Imaging Asteroids) to capture the event up close, which had been deployed from the spacecraft on 11 September. The device is programmed to record and capture DART’s impact, getting images of the debris ejected from the collision and a view of the newly-formed crater.

The Italy-built cubesat was to observe the crash from about 1,000 kms away and then zoom into the fresh site of debris and collision.

The spacecraft had also been transmitting other images of the asteroid which shall be captured by its Didymos Reconnaissance and Asteroid Camera for Optical Navigation (DRACO) camera.

During the event, the images streamed back to Earth were at a rate of one per second. The boulder-covered surface of the egg-shaped asteroid reminded scientists of Ryugu and Bennu, two other asteroids that have recently been visited by spacecraft. Dimorphos is thought by scientists to be an asteroid rubble pile comprised of weakly-connected rocks.

Dimorphos is relatively unknown

Dimorphos is the size of a football field and does not pose any immediate threat to Earth. Scientists are aware of Dimorphos’ size and history, but still do not understand its chemical composition.

The DART mission not only tests the viability of a device that can offset the impact of a potential threat, but also bridges the gap to create a better understanding of the asteroid itself.

Dimorphos is 520 feet or 160 metre wide and is orbiting the much larger 2,560 feet or 780 metre wide asteroid called Didymos. While Didymos is still better understood in the scientific community, Dimorphos requires further speculation. “We know that it’s a separate body, but we know very little about the shape of the asteroid. We don’t know if Dimorphos is elongated or spherical; we don’t know whether it’s a single rock or a pile of boulders,” said Terik Daly, a deputy instrument scientist on DART’s Didymos Reconnaissance and Asteroid Camera for Optical navigation (DRACO), and a planetary scientist at Johns Hopkins Applied Physics Laboratory, which manages the DART mission for NASA to

It is usually recommended that a 5-10 years buffer or notice period is essential for Earth to prepare itself against a killer asteroid attack. And now that all has gone well with the mission so far, we may just be one step closer to a remarkable feat that shall aid humanity from any possible celestial threats.

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