Nasa has developed an early warning system capable of predicting the trajectory and potential threat of enormous, planet-threatening asteroids in just ten minutes. Called Scout, the technology continuously scans for reports of "Near Earth Objects".
Located in Nasa's Jet Propulsion Laboratory (JPL) in Pasadena, California, Scout is designed to locate and investigate objects in the depths of space. Upon finding logs that could indicate a significant risk to Earth, Scout then co-ordinates a wider scan using telescopes from around the globe to refine the data and analyse its flight path.
Its method of alerting other telescopes paid for by Nasa not only spots the larger, more obvious asteroids, but could also be key in finding and analysing smaller objects whose orbits are harder to predict without data gleaned from multiple observatories.
The system was recently called into action on 25 October, after it was alerted to reports of an asteroid dubbed UR36, which initially was deemed to be on a collision course with Earth. It later passed Earth today (31 October) at 3:13am.
UR36 was originally spotted by a telescope in Hawaii, with the initial recordings sent to the Minor Planet Center at the Smithsonian Astrophysical Observatory. In a process that would normally take days, Scout evaluated the preliminary report and judged that it would miss the Earth by around 310,000 miles in around ten minutes.
Three additional reports from observatories across the planet confirmed Scout's findings, estimating that the asteroid measured between 5 meters and 25 meters across.
Paul Chodas of Nasa's JPL explained the reasoning behind Scout to NPR. "The Nasa surveys are finding something like at least five asteroids every night," he said. "When a telescope first finds a moving object, all you know is it's just a dot, moving on the sky. You have no information about how far away it is.
"The more telescopes you get pointed at an object, the more data you get, and the more sure you are how big it is and which way it's headed. But sometimes you don't have a lot of time to make those observations."
JPL's Davide Farnocchia also explained that "objects can come close to the Earth shortly after discovery, sometimes one day, two days, even hours in some cases. The main goal of Scout is to speed up the confirmation process".
While Scout is primarily on the lookout for smaller threats that go under the radar, its sister project – Sentry – is hunting for colossal, city-destroying objects that could hit decades from now.
"Our goal right now is to find 90% of the 140-meter asteroids and larger," Chodas told NPR, estimating that the technology is currently "able to find only 25% to 30% of the estimated population of objects that size".
While Sentry is currently active, Scout is still in testing and is expected to become operational "later this year". When both are active, the Scout system will pass logged and identified threats onto Sentry, forming a symbiotic network of asteroid detection.