An asteroid is headed towards Earth tonight and is estimated to miss the planet by a mere 310,000 miles. We know this thanks to a new tool from NASA called "Scout," which calculated that this particular asteroid is not a danger to our planet and its inhabitants.
Scout is a computer program that's being tested at the NASA Jet Propulsion Laboratory in California as an early warning system. The program gathers data from multiple telescopes to identify which celestial bodies qualify as "Near-Earth Objects" (NEOs). The space agency defines NEOs as comets or asteroids that have entered "Earth's neighborhood" from the gravitational pull of other planets. Data gathered by scientists from this year alone, according to the International Astronomical Union, have discovered over 1,500 new NEOs.
Scout is anticipated to be officially up and running later this year—and focuses solely on relatively small space objects, which are more difficult to spot since they are not as bright as larger asteroids. Take tonight's asteroid, for example, which is estimated to measure anywhere from 16.5 feet to 80 feet across. Without Scout, smaller asteroids are often discovered right before they pass earth. With Scout, scientists can learn of smaller NEOs days in advance and then start calculating if there is any risk for Earth while also ordering other telescopes to confirm the findings.
Tonight's asteroid was spotted by the NASA-funded Panoramic Survey Telescope & Rapid Response System in Maui, Hawaii five days ago. The data was analyzed by Scout, which revealed the celestial body would be missing the planet by 310,000 miles—for comparison, Earth's moon is 238,900 miles away—and the calculation was verified by three other telescopes.
Astronomer Paul Chodas, manager of the NASA NEO Program Office at the Jet Propulsion Laboratory, told NPR that asteroids passing the planet are a nightly occurrence—roughly five a night—but knowing which ones are harmful is the challenge.
"When a telescope first finds a moving object, all you know is it's just a dot, moving on the sky," said Chodas. "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 you're 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."
And in the event a larger body is headed our way, rest easy knowing NASA has a complementary, fully operational program called Sentry to pinpoint asteroids that can do severe damage.