Nasa DART mission - as it happened: Nasa successfully smashes spacecraft into asteroid in first major test
Nasa completes the first-ever planetary defence mission, an attempt to change the course of an asteroid by hitting it with a spacecraft
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Your support makes all the difference.Nasa‘s asteroid-deflecting DART spacecraft successfully slammed into its target on Monday, 10 months after launch.
The test of the world’s first planetary defense system will determine how prepared we are to prevent a doomsday collision with Earth.
The cube-shaped “impactor” vehicle, roughly the size of a vending machine with two rectangular solar arrays, flew into the asteroid Dimorphos, about as large as a football stadium, and self-destructed around 7.14pm EDT (11pm GMT) some 6.8 million miles (11 million km) from Earth.
The mission’s finale tested the ability of a spacecraft to alter an asteroid’s trajectory with sheer kinetic force, plowing into the object at high speed to nudge it astray just enough to keep our planet out of harm’s way.
It will be the first time humanity has changed the motion of an asteroid, or any celestial body. Nasa has a live stream of the event, which you can find at the top of our live blog below.
What next?
As the image of Dimorphos grew from a faint spec, to a grey smudge, and then a real object in the camera’s of Nasa’s Dart mission Applied Physics Laboratory Dart Mission Systems Engineer Elena Adams breathed a sigh of relief.
“That was the defining moment,” Dr Adams told reporters at a post-mission press conference Monday evening.
Dr Adams and her colleagues at the APL control room in Laural Maryland were largely able to stand and watch closely as Dart drew near its target, the asteroid Dimorphos, just as members of the public did, the spacecraft having been set to fly autonomously to its terminal destination in the last five minutes of its life.
“As we were getting close to the asteroid, there was a lot of both terror and joy, because we saw that we were going to impact this asteroid was coming into the field of view of the first time,” Dr Adams said. “All of us were kind of holding our breath.”
Now that its over, and successful, she’s “ a little numb,” she said. “So many years of work are now complete.
Dr Adams has been working on the Dart mission for the past seven years.
But the mission isn’t actually over yet. In the coming days, weeks and months, scientists will begin getting back images and data from telescopes and radar that will help confirm if Dart was successful in moving the orbit of the asteroid it struck.
The ultimate conclusion of the mission is actually years away, when the European Space Agency Hera mission visits Dimorphos in 2026 to view the impact creater left behind by Dart, the first ever planetary defense mission.
The James Webb Space Telescope is watching Didymos right now
At 9.08pm EDT, the James Webb Space Telescope Observations Twitter account announced the big space telescope had a new target for the next 12 minutes: Didymos, the large companion asteroid around which Dart’s target orbits.
Just less than two hours after Nasa’s Dart smashed into the small, egg-shaped asteroid Dimorphos at 14,400, the Webb telescope is using it’s Near-Infrared Camera (Nircam) instrument to survey the system, and may obtain infrared images of the ejecta thrown out from Dimorphos by Dart’s impact. That’s particularly likely given that the last images from Dart showed that Dimorphos is likely a “rubble pile” type asteroid, a loose conglomeration of material rather than a big solid rock.
“If this is actually a rubble pile, that means it is pretty low in strength, and that means you will get a lot of ejecta,” Johns Hopkins Applied Physics Laboratory Dart instrument scientist Carolyn Ernst told reporters following the Dart impact. “If you could hover over it right now, there could still be ejecta coming out because the gravity of this thing is so low.
A cute pile of rubble
Despite its approaching at 14,400 miles per hour, Nasa’s Dart spacecraft was able to capture incredibly detailed images of the asteroid Dimorphos before it slammed into the egg-shaped space rock at 7.14pm EDT Monday evening.
“That moon looked very egg shaped with a bunch of boulders on top like it’s a pile of rubble,” Carolyn Ernst, instrument scientist for Dart’s navigation camera at the Johns Hopkins Applied Physics Laboratory told reporters Monday night. “It’s adorable, this little moon. It’s so cute.”
Rubble pile asteroids are not solid rock or metal ore, but are instead loosely consolidated mixtures of other rocks,clay, sand, ice, and other materials. Learning more about what the asteroid Dimorphos was made out of was an important part of the Dart mission, as any the approach taken by any future missions to deflect an asteroid will depend greatly on that asteroid’s consistency.
And Dart’s camera’s didn’t just provide exquisite images of the features on Dimorphos — they also caught its larger companion Didymos as the spacecraft sped toward its fate.
“I was a little surprised by the shape of Didymos too ... it was a little more elongated than I thought,” Dr Ernst said. As more images become available from other sources, she said, “We’re going to be able to tell a lot about how the system formed and what it has experienced over time.
Those sources include ground based telescopes, the Hubble and James Webb Space Telescopes, and the Light Italian CubeSat for Imaging of Asteroids, or LiciaCube, a small space craft that piggy backed on Dart until relatively recently in its travels.
While images taken from the space telescopes and other instruments may take awhile to reach the public, LiciaCube images could be made public in the next couple of days.
Nothing went wrong
At the end of the day, the Dart mission went exceptionally well, according to the team of Johns Hopkins Applied Physics Laboratory engineers and scientists that made it possible.
“This mission was right down the middle of what we expect and we made no adjustments,” Mark Jensenius, a guidance and navigation control engineer at the Applied Physics Laboratory, told reporters after the successful Dart impact, “Zero.”
“I was actually kind of disappointed,” APL Dart Missions Systems Engineer Elena Adams added. “We planned for all these contingencies and then we did none of them.”
The mission control team at APL had practiced 21 contingencies in case something went wrong with the Dart spacecraft, which was almost entirely autonomous in its last hour of flight toward the asteroid Dimorphos. Those contingencies includes how to conserve propellant and come around for another pass if they somehow missed the small asteroid.
In the end, they hit it nearly dead center, within about 17 meters of the bullseye.
Sleeping well thanks to Dart
Dart successfully impacted the small asteroid Dimorphos, proving that it’s possible to build a spacecraft to autonomously target and strike a distant asteroid at high speed.
Although it will take longer for scientists to collect more observations and determine how much Dart actually altered the orbit of Dimorphos, the first big challenge, proving the concept of a kinetic impactor, has been met. That means the response to any future threat from a hazardous asteroid or comet can be met with models, planning and a physical response, according to Applied Physics Laboratory Dart Missions Systems Engineer Elena Adams, rather. Humanity’s potential response to the kind of threat that once wiped out the dinosaurs is no longer purely theoretical.
“As far can tell, our first planetary defense test was a success, and I think we can all clap to the that,” Dr Adams told reporters at APL in Maryland following the Dart impact, receiving a great applause. “I think all earthlings should sleep better — I know I will.”
Dart a “real genefit for humanity"
Nasa’s Dart mission was a major technical achievement that provided incredible views of a distant asteroid never before seen by human eyes, but it was also humanity’s first step toward taking an active role in protecting ourselves, and all other life on planet Earth, from dangerous asteroid or comet strikes.
“At its core, DART represents an unprecedented success for planetary defense, but it is also a mission of unity with a real benefit for all humanity,” NASA administrator Bill Nelson said in a statement. “As NASA studies the cosmos and our home planet, we’re also working to protect that home, and this international collaboration turned science fiction into science fact, demonstrating one way to protect Earth.”
While neither the 525-foot diameter Dimorphos, the asteroid Dart successfully struck at 7.14 p.m. EDT Monday, nor its larger, 2,560-foot-diameter companion asteroid Didymos, pose a threat to Earth. But that’s what made the system a good laboratory for testing the “kinetic impactor” technique that could one day divert such asteroids if they were on a collision course with Earth.
An asteroid the size of Dimorphos, if it struck the Earth, could generate as a blast releasing energy equivalent to 170 million tons of exploding TNT, according to University of North Dakota assistant professor of Space Studies Sherry Fieber-Beyer, far more than the 50 million tons of energy released by the most powerful thermonuclear bomb ever detonated.
But engineers believe that a spacecraft like Dart could successfully divert an asteroid like Dimorphos if it were headed toward Earth, given a few years heads up. Now the data from Dart will help scientists and engineers adjust their models and learn exactly what they might need to do, and how to do it, if a big space rock appears with Earth’s name on it.
“Planetary Defense is a globally unifying effort that affects everyone living on Earth,” Thomas Zurbuchen, associate administrator for Nasas Science Mission Directorate said in a statement. “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.”
Dart fly over your Google search results
Nasa’s Dart mission made history Monday night, becoming the first spacecraft to ever target and slam into an asteroid in an attempt to change the asteroid’s trajectory through space.
Now, Google has given the groundbreaking spacecraft a tip of the hat, or at least the search result. In the same playful spirit of the Google doodles that have honored scientists, artists, and the late Queen Elizabeth II, Google results currently feature a cameo by the now departed Dart spacecraft.
If you type “DART mission” into a Google search bar, the Dart spacecraft swoops across the screen from the left and knocks your search results temporarily askew.
Nasa posts the Dart re-run
Nasa’s has shared a short video replay of the Dart mission’s successful final moments on the social media network Twitter.
The space agency posted the short video shortly after its Dart spacecraft smashed into the asteroid Dimorphos at 14,400 miles per hour at 7.14pm EDT Monday evening.
In the video, which was assembled from images taken about every second by the Dart spacecraft’s navigation camera, Dimorphos is the smaller gray ovoid seen at the center of the field of view. The larger asteroid seen initially to the lower left of Dimorphos as Didymos, the larger companion of Dimorphos, around which the latter orbits as a moonlet.
First ground-based images of Dart impact
The first images of the Dart mission impact of the asteroid Dimorphos are now available thanks to the Asteroid Terrestrial-impact Last Alert System, or Atlas, a project of Nasa and the University of Hawaii.
The Atlas project Twitter account shared a short video Monday night that shows Dimorphos as a bright light moving against a background stars. The Dart spacecraft’s impact can be seen as a sudden brightening of the light followed by a whispy cloud that puffs off of the light, which is likely the material ejected from Dimorphos by the impact.
The Atlas project automatically scans the night sky looking for small asteroids that have been missed by existing surveys. The project uses four ground-based telescopes, two in Hawaii, one in Chile, and another in South Africa, according to the project website.
Dart mission could protect Earth against killer asteroids
Big asteroid impacts are rare, but the geological record shows they do happen.
The Chicxulub impact that wiped out the dinosaurs took place around 66 million years ago when an asteroid about 6 miles in diameter crashed into what is now the Yucatán Peninsula in Mexico.
Around 790,000 years ago, a smaller asteroid impact likely wiped out 10% of our human ancestors living in southeast Asia at that time, according to University of North Dakota assistant professor of Space Studies Sherry Fieber-Beyer.
But with the success of the Dart mission impact of the small asteroid Dimorphos on Monday evening, contemporary humans have gone a step further than our ancestors could ever have dreamed. By testing the possibility of diverting the trajectory of an asteroid, Nasa and the Johns Hopkins Applied Physics Laboratory have shown that unlike the dinosaurs, we needn’t be caught unawares and unarmed by asteroid or comet engendered Armageddon.
“DART’s success provides a significant addition to the essential toolbox we must have to protect Earth from a devastating impact by an asteroid,” Nasa’s Planetary Defense Officer Lindley Johnson said in a statement. “This demonstrates we are no longer powerless to prevent this type of natural disaster. Coupled with enhanced capabilities to accelerate finding the remaining hazardous asteroid population by our next Planetary Defense mission, the Near-Earth Object (NEO) Surveyor, a Dart successor could provide what we need to save the day.”
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