A University of Arizona space mission planned for the next decade will help scientists better track and predict encounters between asteroids and other celestial bodies and Earth.
About 1,000 people were injured in Chelyabinsk, Russia, on Feb. 15 when a meteor unexpectedly entered Earth’s atmosphere. The meteor approached Earth from the direction of the sun and was relatively small and thus difficult for ground-based observers to spot.
While many asteroids and other near-Earth objects are tracked and closely watched, accurately predicting how they will encounter Earth can be difficult for many reasons, including a phenomenon known as the Yarkovsky effect.
“Right now the factor that prevents us from being able to present these orbits beyond about 100 years is something called the Yarkovsky effect,” says Edward Beshore, deputy principal investigator for the Origins Spectral Interpretation Resource Identification Security Regolith Explorer Mission, also called OSIRIS REx.
“It’s the absorption of light by the asteroid and the re-radiation of it as heat," Beshore says. "That heat acts as a little rocket thrust, and that actually can change the orbit of the asteroid over a long period of time. If we understand that much better we hope it will improve our ability to predict the orbits of these objects, and that’s one of the principle scientific objectives of our mission.”
The OSIRIS REx mission is to visit an asteroid named 1999 RQ 36 and characterize it before grabbing a sample of its surface for return to Earth in 2023. In addition to acquiring a few ounces of the asteroid, the entire process of finding and observing the asteroid for more than a year will lead to a better understanding of how future asteroids could affect Earth.
Watch NOVA Wednesday, 8 p.m. on PBS 6 for more on the Russian meteor strike.