NASA Smashes Spacecraft Into Asteroid In World’s First Planetary Defense Test
NASA has intentionally crashed a 1,260 lb (570 kg) spacecraft into the surface of a wandering asteroid, in order to assess our ability to avoid a potentially devastating collision with Earth.
Since its birth some 4.5 billion years ago, Earth has been under constant bombardment from material left over from the creation of the solar system. Most of these pieces of interplanetary debris are so small that they are ripped apart upon colliding with Earth’s dense atmosphere.
However, once every few million years a monster asteroid large enough to survive atmospheric entry strikes our planet’s surface with cataclysmic force.
NASA's DART Spacecraft Completes First Planetary Defense Mission
The most recent monster impact happened roughly 66 million years ago, when a 6 mile (10 km) wide asteroid collided with our planet, and gouged out a massive crater, the remains of which can still be found on the Yucatan Peninsula today.
A combination of the devastation wrought by the initial impact, and the environmental changes brought about by the resulting fallout, sounded the death knell for 75 percent of all animal life on Earth, and effectively ended the age of the dinosaurs.
It is completely possible that the impact of another enormous asteroid could doom the human race to extinction. However, unlike the dinosaurs, we may have the technological capabilities and the foresight needed to avert such a fate.
NASA’s Double Asteroid Redirection Test (DART) is the first step along the path to developing a planetary defence against colossal asteroids. Compared to Hollywood movies that deal with similar themes, the mission itself is relatively simplistic. There is a distinct lack of nuclear weapons, oversized drills, or Bruce Willis-es.
Instead, NASA has opted to command a solitary - and obviously uncrewed - probe to strike an asteroid head-on while travelling at 14,000 miles per hour in order to see how the impact would shift its orbit. The idea is that, if you detect a potentially dangerous asteroid early enough, then it’ll only take a small shunt to send it onto a safer path.
“Planetary Defense is a globally unifying effort that affects everyone living on Earth,” states Associate Administrator for the Science Mission Directorate at NASA Headquarters in Washington, Thomas Zurbuchen. “Now we know we can aim a spacecraft with the precision needed to impact even a small body in space. Just a small change in its speed is all we need to make a significant difference in the path an asteroid travels.”
The target for the mission is the 530 ft (160 m)-wide asteroid/moonlet Dimorphos, which orbits a larger 2,560 ft (780 m) wide asteroid known as Didymos as it careens through the solar system.
NASA has been sure to stress that neither asteroid posed a threat to Earth either before, or after the test.
In the hours leading up to the impact, DART used sophisticated navigation software to interpret images captured by its onboard camera to autonomously guide itself in. During this time the doomed probe was able to capture detailed images of Dimorphos’ bleak, rubble strewn surface.
IMPACT SUCCESS! Watch from #DARTMIssion’s DRACO Camera, as the vending machine-sized spacecraft successfully collides with asteroid Dimorphos, which is the size of a football stadium and poses no threat to Earth. pic.twitter.com/7bXipPkjWD
— NASA (@NASA) September 26, 2022
Finally, on September 26, at 7:14pm Easter time, after years of development and 10 months navigating interplanetary space, mission handlers announced that DART had successfully impacted its target.
In the wake of the impact the asteroid pair were observed by a number of ground-based and orbital observatories - including the James Webb Space Telescope - which sought to ascertain how much the impact had changed Dimorphus' trajectory.
More specifically, the global scientific community wanted to know how the collision had altered the amount of time it takes the smaller asteroid to orbit its larger brother, and to observe the behavior of the material that was blasted from its surface.
The heavy-duty telescopes were aided in this task by a tiny Italian-made cubesat, which had hitched a ride with the DART mothership, and was deployed 15 days prior to the mission finale.
The sole purpose of the tiny satellite is to capture imagery of DART and the damage inflicted on the asteroid system from a different perspective. However, due to the diminutive size of its antenna it will take weeks to send the images back to Earth.
Gorgeous Photos of Earth from Space
Computer modelling of the event projects that the impact will have reduced Dimorphus’ orbital period by roughly 10 minutes, or 1 percent. The in-depth observations will be compared to these models to refine them, and better scientists' understanding of asteroids.
Regardless of the final orbital shift, the DART mission can only be considered a success. It has demonstrated that an uncrewed probe can autonomously perform the calculations and trajectory corrections needed to successfully strike an asteroid, even when it is orbiting a larger body.
The asteroid duo is set to be the target of the European Space Agency’s Hera mission four years down the line in 2026, during which a mothership and cubesat will perform follow-up observations.
“This first-of-its-kind mission required incredible preparation and precision, and the team exceeded expectations on all counts,” comments Ralph Semmel, Director of Johns Hopkins Applied Physics Laboratory in Maryland. “Beyond the truly exciting success of the technology demonstration, capabilities based on DART could one day be used to change the course of an asteroid to protect our planet and preserve life on Earth as we know it.”
This story originally appeared on: IGN - Author:Anthony Wood