Is our solar system really a shooting gallery, with Earth as a target for asteroids?
As humanity prepares for its first-ever planetary defense exercise, NASA Officials recently reassured Earthlings that they had little to worry about.
double asteroid redirection testArrow), which will collide with a probe into an asteroid moon called Didymus on September 27 in an attempt to change its orbit around its parent body Demorphos, is just part of our toolbox against the potential threat asteroids. (Spoiler alert: Not to worry now.)
NASA, international agencies and telescopes around the world have been systematically scouring the skies for more than a generation, searching for any evidence of asteroids that may pose a serious threat to human civilization. Just a short list of outer space The rocks are absolutely threatened, NASA says there is nothing to worry about for the next century at least.
“We are constantly searching the sky for potential new asteroids and threats,” Andrea Riley, executive director of the DART program at NASA, said during a press conference on September 12.
Pictures: asteroids in deep space
Dimorphos, which are 560 feet (170 meters) in diameter, fall into the category of objects that NASA is tracking to ensure they are not on a collision course with them. a land. However, the asteroid is not considered a threat at all. Riley also emphasized that NASA is more interested in objects larger than one mile (1.6 kilometers) in diameter, which the agency has already tracked down at least 90% of the population.
Finding things is one hurdle, and learning how to deal with them is the next step. The “kinetic impact” strategy that DART will demonstrate is by no means the only way to move an asteroid out of the way. Researchers have come up with a number of other possible approaches, from blowing space rocks away with nuclear bombs to coating them to change their brightness, so that sunlight can help push them out of the way.
“This test will help give us confidence that we have a mitigation strategy in place should any threat ever be identified,” Riley said of DART.
But with space being such a big place, the chance of a cosmic collision remains slim, NASA officials have confirmed — at least in the near future. There are enough asteroids in the vicinity of Earth that eventually larger ones should head to our planet. Just ask the dinosaurs.
Related: The darkness caused by a dinosaur-killing asteroid wiped out life on Earth in 9 months
“If you wait too long, something is up,” Thomas Zurbuchen, associate administrator for NASA’s Science Directorate, told reporters during the same press conference.
“These things have really affected our history, and we have the geological record to prove it, with [crater] info from the moon and in other places.”
He said that NASA is looking for a low-cost solution to solve any kinks now, when asteroid defense is not an urgent issue. In this way, when the time comes, the Agency and its international partners will be prepared to deal with this issue.
“It actually allows us to move the state of knowledge forward, along with the international community, who wants to follow up with a mission to really help translate everything we’ve learned into the scientific context,” Zurbchen said. “It’s the time to do it. It’s not an outside schedule that has been placed on us.”
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DART is just one of the space missions recently tasked with learning more about asteroid orbits. NASA agency Osiris Rex The spacecraft is on its way to Earth, for example, with a sample of the asteroid Bennu. Scientists will study the sample to assess the composition of that asteroid, in part to improve how such objects move through space.
Zurbuchen said the data from OSIRIS-REx also helps astronomers better assess the effect of thermal radiation on the asteroid. Over time, the Yarkovsky effect may affect the asteroid’s orbit; As such, NASA is including thermal effects in its model to “really eliminate the largest uncertainties of orbit propagation over long periods,” he said.
Another helper in this effort is NEO . Surveyor, He said. This is an upcoming NASA mission that will search for more asteroids in space and also aims to better predict their paths around Solar System.
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As scientists do their best to protect Earth from the problem of space rocks, Nancy Chabot of the DART mission has urged them to think about the real threat of asteroids.
There are only four near-Earth asteroids resembling the body that killed the dinosaurs, which is believed to have been about 6.5 miles (10 kilometers) in diameter, Chabot, head of DART coordination at Johns Hopkins Applied University, said. Research laboratory. “We’ve found them all, we’re tracking them, and none of them pose a threat for the foreseeable future,” she emphasized.
She said that even the smallest things are well tracked. She said scientists have found more than 95% of the objects over 0.6 miles (1 kilometer) in diameter, and none of them pose an immediate threat either.
Scientists are now focusing their attention on finding objects a few hundred feet in diameter, in which they found about 50% of the population. And while the known objects don’t represent a threat scientists worry about, she said, finding more will bolster our planetary defense.
Learning how to deal with such objects in space may prevent “regional havoc, [which] It can be the size of a city, a small country, or a small country. This is why Demorphos is an ideal target for this first planetary defense mission, because it is this big.
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