A tool to spot killer Asteroids

Researchers have built an algorithm called Tracklet-less Heliocentric Orbit Recovery, or THOR that can scan old astronomical images for unnoticed space rocks, helping to detect objects that could one day imperil Earth.
B612 Foundation, a nonprofit group, announced the discovery of more than 100 asteroids.
What is remarkable is that B612 did not build a new telescope or even make new observations with existing telescopes.
Instead, researchers financed by B612 applied cutting-edge computational might to years-old images — 412,000 of them in the digital archives at the National Optical-Infrared Astronomy Research Laboratory, or NOIRLab — to sift asteroids out of the 68 billion dots of cosmic light captured in the images.
Today, of the estimated 25,000 near-Earth asteroids at least 460 feet in diameter, only about 40 percent of them have been found.
The other 60 percent — about 15,000 space rocks, each with the potential of unleashing the energy equivalent to hundreds of million of tons of TNT in a collision with Earth — remain undetected.

Process to identify Asteroids

Typically, asteroids are discovered when the same part of the sky is photographed multiple times during the course of one night.
As objects that are much closer, within the solar system, move quickly, and their positions shift over the course of the night.
Astronomers call a series of observations of a single moving object during a single night a “tracklet.”
A tracklet provides an indication of the object’s motion, pointing astronomers to where they might look for it on another night.
The algorithm is currently configured to only find main belt asteroids, those with orbits between Mars and Jupiter, and not near-Earth asteroids, the ones that could collide with our planet.
Identifying near-Earth asteroids is more difficult because they move faster.
Different observations of the same asteroid can be separated farther in time and distance, and the algorithm needs to perform more number crunching to make the connections.
THOR not only has the ability to discover new asteroids in old data, but it could also transform future observations as well.