Analyzing digital image files of the universe obtained by telescopes, a powerful algorithm named after the Norse god has identified 104 asteroids 140 meters in diameter that had gone unnoticed. You can find thousands more in no time.
Researchers at the University of Washington have developed a new algorithm that has detected 104 asteroids 140 meters in diameter in the solar system that had previously gone unnoticed.
They discovered them by applying the algorithm to 412,000 digital images archived at the US National Science Foundation’s National Research Laboratory for Optical-Infrared Astronomy.
Of the 25,000 near-Earth asteroids that have a diameter of 140 meters, only about 40 percent of them have been identified.
Of the other 60 percent, about 15,000 space rocks with those dimensions, we don’t know where they are or what their orbital paths are. If one of them were to collide with Earth, it would release energy equivalent to hundreds of millions of tons of TNT on impact.
Algorithm against uncertainty
The new algorithm is named after the god of thunder, THOR, although its meaning is different: Tracklet-less Heliocentric Orbit Recovery. And it has already proven its effectiveness: the rocky bodies discovered with its help have been confirmed as asteroids by the International Astronomical Union’s Minor Planet Center (MPC).
The Asteroid Institute, a program of the B612 Foundation, which has been running THOR on its cloud-based astrodynamics platformcalled Asteroid Discovery Analysis and Mapping (ADAM), is the one that has tracked and identified the dangerous asteroids recognized by MPC.
With these new asteroids confirmed by the MPC and added to its registry, researchers using the Institute’s data cloud can report thousands of additional new discoveries by applying THOR more extensively.
THOR can analyze astronomical images not only to identify points of light that could be asteroids, but also to determine which points of light in images captured on different nights are from the same asteroid.
THOR builds a test orbit corresponding to the observed point of light, assumes a specific distance and speed, and then calculates the asteroid’s position on subsequent and prior nights.
This new algorithm, developed by astrophysicist mario juricdirector of the DIRAC Institute at the University of Washington in Seattle, and his doctoral student, Joachim Moeyenswill significantly change the asteroid search strategy, according to its creators.
It will also improve the performance of projects such as LSST (Legacy Survey of Space and Time), a 10-year study to study the southern sky, to be carried out at the Vera C. Rubin Observatory, currently under construction in northern Chili.
The researchers believe that, due to rapidly developing computer speeds, it is possible to improve projects like the LSST by developing innovative software rather than, for example, building ever more powerful telescopes.
If, after further tests of the algorithm, it is shown to be applicable to LSST, the researchers consider it plausible to change the observing strategy and improve the quality of the data, not only for dangerous asteroids, but also for other objects, including galaxies, stars and quasars.
Asteroids or planetoids are celestial bodies, made of stone or metal, of more than a meter in diameter, that orbit around the Sun alone or in a group of similar bodies.
In addition to the 140-meter-diameter asteroids that THOR has already identified, there are even larger asteroids, about 50 meters in diameter, that hit Earth once every 1,000 years. Each of them can destroy a large city.
Asteroids can be even larger, up to a kilometer in diameter, causing global damage if they hit. They fall to Earth about every half a million years.
The most important impact occurred 65 million years ago, when an asteroid of 10 to 14 kilometers in diameter fell on Yucatan and caused the extinction of the dinosaurs, but also of various species of plants and animals. On average, hits like an asteroid crash in the Yucatan occur every 100 million years.
“Discovering and tracking asteroids is crucial to understanding our solar system, enabling space development, and protecting our planet from asteroid impacts,” Ed Lu, executive director of the Asteroid Institute, said in a statement.
“With THOR, any telescope with a file can become an asteroid-hunting telescope. We are using the power of massive computing to extract not only more discoveries from existing telescopes, but also to find and track asteroids in historical images of the sky that had previously gone unnoticed because they were never intended for asteroid searches.”
ReferenceTHOR: An Algorithm for Cadence-independent Asteroid Discovery. Joachim Moeyens et al. The Astronomical Journal, Volume 162, Number 4. DOI:https://doi.org/10.3847/1538-3881/ac042b