NASA’s new Scout system – a computerized system designed to determine whether asteroids pose a risk to the Earth, has spotted a large asteroid which will come close to the planet – but not hit – late Sunday night. According to a report from NPR , the Scout system, which is brand new and currently being tested at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, detected a large asteroid heading our way earlier in the week but determined that it would miss by 310,000 miles – extremely close in astronomical terms – close enough to be affected by Earth’s gravity.
Tonight’s asteroid was discovered by the Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) array on Maui, Hawaii, a NASA-funded telescope system. Scout scooped the preliminary details when they appeared on the website of the Minor Planet Center, part of the Smithsonian Astrophysical Observatory, and did some quick calculations to determine if Earth was in danger. It determined that the asteroid was headed for Earth, but not quite closely enough to start worrying. NASA pays for several telescopes like the Pan-STARRS array to scan near space every night and typically discovers at least five asteroids a night.
The trick, says astronomer Paul Chodas of JPL, is figuring out which ones might pose a danger – a problem Scout was created to solve.
“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 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.”
“Objects can come close to the Earth shortly after discovery, sometimes one day, two days, even hours in some cases,” added JPL’s Davide Farnocchia.
“The main goal of Scout is to speed up the confirmation process.”
After making its risk calculation, Scout also sends instructions to other telescopes to conduct a follow-up and determine if its risk projections are accurate. Once Scout had made its determination on this asteroid, three other telescopes – one at the Steward Observatory, another called Spacewatch, and a third at Tenagra Observatories – confirmed that it would miss Earth by a safe margin. They also determined that the asteroid was some five to 25 meters across. That doesn’t seem like much, but according to Universe Today , it’s potentially as large as the Tunguska, Siberia meteor in 1908, which leveled forests across thousands of square kilometers – and that one broke up before impact, exploding with a force of 10 to 15 megatons of TNT. That’s as much explosive force as the strongest nuclear weapon ever tested by America, many orders of magnitude stronger than the bombs which destroyed Hiroshima and Nagasaki.
Scout is mostly looking for smaller asteroids; it’s coupled with another system, Sentry, which has already been fully operational for several years, looking for larger, more dangerous objects which might hit Earth over the next hundred years. “Our goal right now is to find 90 percent of the 140 meter asteroids and larger,” said Cholas, but admitted that right now, we’re only detecting 25 to 30 percent of what astronomers believe is out there.
One might wonder what the point of all of this is, but astronomer Ed Lu, CEO of an organization called B612, is aiming to create a solution to the problem – assuming that we can detect dangerous objects early enough. Oddly, it’s not all that different from the solution proposed by movies like Armageddon – essentially, strap a bomb to the rock. Only in this case, the bomb is planted decades in advance and serves simply to nudge an asteroid off-course; by the time it’s traveled millions of miles, a small change is enough to drastically alter an asteroid’s path.
“I believe in the next 10 to 15 years we’ll actually be at the point where we as humans can say, ‘Hey, we’re safe from this danger of large asteroids hitting the Earth.’”
[Featured Image by Christopher Furlong/Getty Images]