Is our solar system really a shooting gallery, with Earth as the target of asteroids?
As humanity prepares for its first planetary defense exercise mission, NASA Officials recently reassured Earthlings that they have little to worry about.
Double Asteroid Redirect Test (Dart), which will slam an asteroid moon probe named Didymos on September 27 for trying to change its orbit around its parent body Dimorphos, is just one part of our toolbox against the potential threat asteroids, (Spoiler alert: nothing to worry about right now.)
NASA, international agencies and telescopes around the world have been systematically scouring the skies for more than a generation, looking for any evidence of asteroids that could pose a serious threat to human civilization. only a short list of space Rocks considered a threat at all, NASA says nothing to worry about for the next century least.
“We’re constantly looking across the skies for potential new asteroids and threats,” Andrea Riley, DART program executive at NASA, said during a press conference on Sept. 12.
In pictures: asteroids in deep space
Dimorphos, 560 feet (170 m) in diameter, is within the class of objects that NASA is tracking to make sure they are not on a collision course. Earth, However, the asteroid is not considered a threat. Riley also emphasized that NASA is more concerned about objects larger than 1 mile (1.6 kilometers) in diameter, for which the agency has already tracked at least 90% of the population.
Finding objects is an obstacle, and learning to deal with them is the next step. The “kinetic impact” strategy that Dart will demonstrate is by no means the only way we have to move the asteroid out of the way. Researchers have explored a number of other possible ways besides atomic bombs, from blowing up space rocks to photographing them to change their brightness so that sunlight can help get them out of the way.
“This test,” Riley said of Dart, “will help give us confidence that we have a mitigation strategy in place should a threat be identified.”
But with space being such a large place, a cosmic accident remains less likely, NASA officials stressed — for the foreseeable future, at least. There are enough asteroids in Earth’s neighborhood that, eventually, a large asteroid is bound to head to our planet. just ask the dinosaur,
“If you wait long enough, an object will happen,” Thomas Zurbuchen, associate administrator for NASA’s Science Directorate, told reporters during the same press conference.
“These objects have really influenced our history, and we have the geologic record to prove it, with [crater] data from Moon And elsewhere,” he said.
NASA is now looking for low-cost solutions to address any glitches when asteroid defense is not an urgent problem, he said. That way, the agency and its international partners will be ready to tackle the issue when the time comes.
“It really allows us to advance the knowledge position with the international community, which really wants to follow through with a mission to help translate all of our learning into a scientific context,” Zurbachen said. . “This is the right time to do it. This is not an external program that was imposed on us.”
Dart is just one space mission recently tasked with learning more about asteroid orbits. of nasa osiris-rex The spacecraft is headed back to Earth, for example, with a sample of the asteroid Bennu. To better refine how such objects move in space, scientists will study the sample to assess the composition of that asteroid.
Data from OSIRIS-REx is also helping astronomers better assess the effects of thermal radiation on the asteroid, Zurbuchen said. with time, yarkovsky effect can affect the orbit of the asteroid; As such, NASA is incorporating thermal effects into its models “to really eliminate the biggest uncertainties for orbit propagation over the long term,” he said.
Another helper in this endeavor is NEO Surveyor, They said. It is an upcoming NASA mission that will look for more asteroids in space and also aim to better predict their paths around them. The Solar System,
While scientists are doing their best to save Earth from the space rock problem, Nancy Chabot of the Dart mission urges perspective to think about the real danger of asteroids.
There are only four near-Earth asteroids that are similar to the object that killed the dinosaurs, which are believed to have been about 6.5 miles (10 km) in diameter, said Chabot, who is the DART coordinate at Johns Hopkins University of Applied. is leadership. Research Laboratory. “We’ve found them all, we’re tracking them, and none of them pose a threat to the foreseeable future,” she emphasized.
She said that even small objects are well tracked. Scientists have detected more than 95% of objects that are more than 0.6 miles (1 km) in diameter, and none of them pose an immediate threat, she said.
Scientists are now focusing their attention on finding objects a few hundred feet in diameter, for which they have found about 50% of the population. The known objects pose no threat, he said, but scientists are concerned, and finding more would enhance our planetary defenses.
learning to manipulate such objects in space “territorial catastrophe, [which] Could be the size of a city or a small state or a small country,” she said. “That’s why Dimorphos is such a perfect target for this first planetary defense mission, because it’s that size.”