NASA recently deployed a new early-warning system to identify asteroids passing dangerously close to Earth, and it looks like the system is working exactly as it should. The program, named Scout, already alerted astronomers to a potential close encounter Earth experienced with a somewhat scary-sized asteroid on Sunday night.
Scout, currently in development down at NASA’s Jet Propulsion Laboratory in Pasadena, California, works by aggregating and analyzing data from a number of different telescopes. When it identifies a near-Earth Object (NEO), it both calculates the risk of impact and collects subsequent data gathered by other telescopes.
A handful of such objects are tracked pretty much every night. Sunday’s asteroid was never on a trajectory to actually crash into the Earth, but it did pass within about 300,000 miles and measured somewhere between around 16 and 80 feet across — which made it the kind of too-close-for-comfort object Scout was designed to alert us to. A companion program called Sentry is tasked with tracking larger ones. Asteroids measuring around 450 feet across are the ones approaching the size capable of destroying a major city, and astronomers hope that Sentry will one day be able to identify around 90 percent of those larger threats.
Of course, Scout and Sentry can only warn us about NEO’s on potentially dangerous trajectories — they can’t actually break them up or move them. Kind of like those weird LifeLock commercials that joke about monitoring the problem without being able to fix them, these kinds of programs still leave it up to us to develop a solution. Astronomer Ed Lu told NPR that the key to being able to divert NEO’s is early detection, at least a decade or two. When they’re that many billions of miles away, they can be “nudged” off course little by little.
NASA’s already on the case, working in conjunction with other major space science entities like the European Space Agency, Observatoire de la Côte d´Azur (OCA), and the Johns Hopkins University Applied Physics Laboratory (JHU/APL). The collaboration, known as the Asteroid Impact and Deflection Assessment (AIDA) Mission, is at the forefront of a potentially life-saving maneuver called the kinetic impact technique. This basically involves a spacecraft smashing into the worrisome asteroid in question, pushing it a fraction of a percent off its orbit. The idea is that by the time it reaches Earth, that gap will have widened significantly enough to keep it at a safe distance.