Huge asteroids have collided with Earth beforerag dinosaur—and if we’re not watching out for all those wrong space rocks, they could crash into our world again, with disastrous consequences. So Ed Lu and Danica Remy of the Asteroid Institute started a new project to track down as many of them as possible.
Lu, a former NASA astronaut and executive director of the institute, led a team that developed a novel algorithm called THOR, which uses massive computing power to compare the points of light seen in different images of the night sky. Uses, then mixes to piece them together. Individual asteroid’s path through the Solar System. They have already discovered 104 asteroids with the system Announcement They were released on Tuesday.
While NASA, the European Space Agency and other organizations have their own ongoing asteroid discoveries, they all face the challenge of parsing telescope images that contain thousands or even 100,000 asteroids. Some of those telescopes may or may not take multiple images of the same area on the same night, which makes it difficult to tell if the same asteroid is visible in multiple photos taken at different times. . But THOR can make a connection between them.
“The magical thing about THOR is that it realizes that out of all those asteroids, it’s in a certain image, and it’s in another image four nights later, and it’s all the same object seven nights later and It can be put together with the trajectory of an actual asteroid,” Lu says. This makes it possible to track the path of the object as it moves, and to determine whether it is on a trajectory to Earth. He says such a formidable task was not possible with older, slower computers. “It is showing the importance of computation in advancing astronomy. What is driving it is that computation is becoming so powerful and so cheap and ubiquitous.”
Astronomers typically spy on asteroids with what’s called a “tracklet,” a vector measured from a number of images, usually taken within an hour. These often include an observation pattern with six or more images, which researchers can use to reconstruct the asteroid’s path. But if the data is incomplete—say, because a cloudy night obstructs the telescope’s view—then that asteroid will remain unconfirmed, or at least inaccessible. But that’s where THOR, which stands for Tracklet-less Heliocentric Orbit Recovery, comes in, making it possible to trace the path of an asteroid that would have otherwise been missed.
While NASA benefits from dedicated telescopes and surveys to find potentially dangerous asteroids, other data sets abound. And Thor can use almost any of them. “THOR replaces any astronomical data set data set where you can search for asteroids. That’s one of the best things about algorithms,” said Joachim Moyens, co-creator of THOR and an asteroid institute at the University of Washington. fellow and graduate student. For this initial demonstration, Moyens, Lu and their colleagues searched for billions of images taken between 2012 and 2019 with a telescope managed by the National Optical Astronomy Observatory, many of them with a sensitive camera mounted on the Blanco 4-meter telescope in the Chilean Andes. was done by