I bet the dinosaurs wish they had thought of that.
NASA will attempt a feat on Monday that humanity has never before accomplished: deliberately slamming a spacecraft into an asteroid to slightly deflect its orbit, in a key test of our ability to stop objects cosmic forces to destroy life on Earth.
The Double Asteroid Redirection Test (DART) spacecraft was launched from California last November and is rapidly approaching its target, which it will hit at about 14,000 miles per hour (23,000 km/h).
Certainly, neither the asteroid Dimorphos nor the bigger sibling it orbits, called Didymos, pose any threat as the pair loop around the Sun, passing about seven million miles from Earth at their closest approach.
But the experiment is one that NASA felt was important to perform before a real need was discovered.
“This is an exciting time, not only for the agency, but in the history of space and the history of mankind, frankly,” Lindley Johnson, planetary defense officer for NASA, said in a briefing Thursday.
If all goes according to plan, impact between the car-sized spacecraft and the 530-foot (160 meters, or two Statues of Liberty) asteroid should occur at 7:14 p.m. ET (2314 GMT) and may be watched on a NASA Live Stream.
By hitting Dimorphos directly, NASA hopes to push it into a smaller orbit, cutting ten minutes off the time it takes to circle Didymos, which is currently 11 hours and 55 minutes – a change that will be detected by telescopes land in the days to come.
The proof-of-concept experiment will turn into reality what has only been attempted before in science fiction, particularly in movies like “Armageddon” and “Don’t Look Up.”
As the craft propels itself through space, flying autonomously for the final phase of the mission as a self-guided rocket, its main camera system, called DRACO, will begin transmitting the first images of Dimorphos.
“It will start as a small point of light and then eventually it will enlarge and fill the entire field of view,” said Nancy Chabot of the Johns Hopkins Applied Physics Laboratory (APL), which houses mission control in a recent briefing. .
“These images will continue until they are gone,” the planetarian added.
Minutes later, a toaster-sized satellite called LICIACube, which separated from DART a few weeks earlier, will make a close pass of the site to capture images of the collision and the ejecta — the pulverized rock thrown out following the impact.
The LICIACube picture will be sent back in the coming weeks and months.
Also watching the event: a number of telescopes, both on Earth and in space, including the newly operational James Webb, which may see a bright dust cloud.
Finally, a full picture of what the system looks like will be revealed when a European Space Agency mission in four years, called Hera, arrives to survey Dimorphos’ surface and measure its mass, which people of science I can only guess at the present time.
Very few of the billions of asteroids and comets in our solar system are considered potentially dangerous to our planet, and none for the next hundreds of years.
But “I guarantee you if you wait long enough, there will be an object,” said Thomas Zurbuchen, NASA’s chief scientist.
We know that from the geologic record—for example, the six-mile-wide asteroid Chicxulub hit Earth 66 million years ago, plunging the world into a long winter that led to the mass extinction of the dinosaurs along with 75 percent of species.
An asteroid the size of Dimorphos, by contrast, would only cause a regional impact, such as the devastation of a city, albeit with greater force than any nuclear bomb in history.
Scientists also hope to glean valuable new information that can inform them about the nature of asteroids in general.
How much thrust DART gives Dimorphos will depend on whether the asteroid is solid rock or more like a “junk pile” of boulders bound by mutual gravity, a property that is not yet known.
We also don’t know its actual shape: whether it’s more of a dog bone or a doughnut, but NASA engineers are confident that DART’s SmartNav guidance system will hit its target.
If it misses, NASA will have another chance in two years, with the spacecraft containing just enough fuel for another pass.
But if it succeeds, then it’s a first step toward a world capable of defending itself against a future existential threat, Chabot said.
NASA will crash a spacecraft into a 525-foot-wide asteroid in September. Here’s how to watch it
© 2022 AFP
Citation: NASA Gears to Deflect Asteroid, Planetary Defense Key Test (2022, September 23) Retrieved September 23, 2022, from https://phys.org/news/2022-09-nasa-gears-deflect-asteroid-key .html
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