NASA's New 'Intruder Alert' System Spots An Incoming Asteroid 
 
 Enlarge this image toggle caption P. Carril/ESA P. Carril/ESA 
 
 A large space rock came fairly close to Earth on Sunday night. Astronomers knew it wasn't going to hit Earth, thanks in part to a new tool NASA is developing for detecting potentially dangerous asteroids. 
 
 The tool is a computer program called Scout, and it's being tested at NASA Jet Propulsion Laboratory in Pasadena, Calif. Think of Scout as a celestial intruder alert system. It's constantly scanning data from telescopes to see if there are any reports of so-called Near Earth Objects. If it finds one, it makes a quick calculation of whether Earth is at risk, and instructs other telescopes to make follow-up observations to see if any risk is real. 
 
 NASA pays for several telescopes around the planet to scan the skies on a nightly basis, looking for these objects. "The NASA surveys are finding something like at least five asteroids every night," says astronomer Paul Chodas of JPL. 
 
 But then the trick is to figure out which new objects might hit Earth. 
 
 "When a telescope first finds a moving object, all you know is it's just a dot, moving on the sky," says 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. 
 
 "Objects can come close to the Earth shortly after discovery, sometimes one day, two days, even hours in some cases," says JPL's Davide Farnocchia. "The main goal of Scout is to speed up the confirmation process." 
 
 The rock that whizzed past Earth tonight was discovered on the night of Oct. 25-26 by the NASA-funded Panoramic Survey Telescope & Rapid Response System (Pan-STARRS) on Maui, Hawaii. Within a few hours, preliminary details about the object appeared on a Web page maintained by the Minor Planet Center at the Smithsonian Astrophysical Observatory. Scout did a quick analysis of the preliminary details and determined that the object was headed for Earth but would miss us by about 310,000 miles. 
 
 Enlarge this image toggle caption Rob Ratkowski/Courtesy of Pan-STARRS Rob Ratkowski/Courtesy of Pan-STARRS 
 
 Additional observations by three telescopes, one operated by the Steward Observatory, another called Spacewatch, and a third at the Tenagra Observatories, confirmed the object would miss Earth by a comfortable margin. Astronomers were also able to estimate the size of the object: somewhere between 5 meters and 25 meters across. In case you're interested, full details about the object's trajectory can be found here. 
 
 Scout is still in the testing phase. It should become fully operational later this year. 
 
 Now Scout is mainly dealing with smallish, very nearby objects. Complementing Scout is another system that is already operational called Sentry. 
 
 Sentry's job is to identify objects large enough to wipe out a major city that might hit Earth in the next hundred years. "Our goal right now is to find 90 percent of the 140-meter asteroids and larger," says Chodas, but right now he estimates they're able to find only 25 to 30 percent of the estimated population of objects that size. 
 
 That number should get better when a new telescope being built in Chile called the Large Synoptic Survey Telescope comes online. NASA is also considering a space telescope devoted to searching for asteroids. 
 
 OK, so let's say you find one of these monster rocks heading for Earth. What then? Astronomer Ed Lu says there is something you can do. He's CEO of an organization called B612. It's devoted to dealing with asteroid threats. 
 
 "If you know well in advance, and by well in advance I mean 10 years, 20 years, 30 years in advance, which is something we can do, " says Lu, "then you can divert such an asteroid by just giving it a tiny nudge when it's many billions of miles from hitting the Earth." 
 
 NASA and the European Space Agency are developing a mission to practice doing just that. 
 
 Lu says in the past decade, people who should worry about such things have begun to make concrete plans for dealing with dangerous asteroids. 
 
 "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,' " he says. 
 
 In the meantime, we'll just have to hope that luck is on our side. ||||| When a meteor exploded over Chelyabinsk, Russia in February, the world’s space agencies found out along with the rest of us, on Twitter and YouTube. That, says former astronaut Ed Lu, is unacceptable—and the United Nations agrees. Last week the General Assembly approved a set of measures that Lu and other astronauts have recommended to protect the planet from the dangers of rogue asteroids. 
 
 The U.N. plans to set up an “International Asteroid Warning Group” for member nations to share information about potentially hazardous space rocks. If astronomers detect an asteroid that poses a threat to Earth, the U.N.’s Committee on the Peaceful Uses of Outer Space will help coordinate a mission to launch a spacecraft to slam into the object and deflect it from its collision course. 
 
 Lu and other members of the Association of Space Explorers (ASE) recommended these steps to the U.N. as a first step to address at the long-neglected problem of errant space rocks. “No government in the world today has explicitly assigned the responsibility for planetary protection to any of its agencies,” ASE member Rusty Schweickart, who flew on the Apollo 9 mission in 1969, said Friday at the American Museum of Natural History. “NASA does not have an explicit responsibility to deflect an asteroid, nor does any other space agency.” The ASE advocates that each nation delegate responsibility for dealing with a potential asteroid impact to an internal agency—before the event is upon us. 
 
 The next step in defending Earth against dangerous asteroids is to find them, Lu said. “There are 100 times more asteroids out there than we have found. There are about 1 million asteroids large enough to destroy New York City or larger. Our challenge is to find these asteroids first before they find us.” 
 
 Early warning is important because it increases the chance of being able to deflect a threatening asteroid once it is found. If a spacecraft struck an asteroid 5 or 10 years before the rock was due to hit Earth, a slight orbital alternation should be enough to make it pass Earth by; if the asteroid wasn’t detected soon enough, evacuating the impact zone may be the only option available. “If we don’t find it until a year out, make yourself a nice cocktail and go out and watch,” Schweickart quipped. 
 
 The B612 Foundation, a non profit Lu founded to address the problem of asteroid impacts, is developing a privately funded infrared space telescope called Sentinel, which it hopes to launch in 2017. The telescope would begin a systematic search for hazardous near-Earth objects. 
 
 The ASE astronauts are also asking the United Nations to coordinate a practice asteroid deflection mission to test out the technologies for pushing a rock off course should the need arise. The meteor in Chelyabinsk, which injured 1,000 people but killed none, was an ideal warning shot across the bow, said American Museum of Natural History astronomer Neil deGrasse Tyson, who hosted Friday’s event—now, it’s time for Earth’s citizens to take action. Lu agreed: “Chelyabinsk was bad luck,” he said. “If we get hit again 20 years from now, that is not bad luck—that’s stupidity.”
– NASA is hard at work to protect the Earth from asteroid threats, NPR reports. The agency's new "Scout" detection system scans the skies above our planet for small, nearby objects that might enter Earth's orbit. In fact, a small one between 5 and 25 meters across will come relatively close to Earth Sunday night, though there's no danger of a strike. Once an asteroid is detected, Scout coordinates data from multiple telescopes across the world in order to ascertain if the object will enter Earth's atmosphere, and if it poses any sort of a threat. While more than 15,000 Near-Earth Objects have been recorded over the course of history, astronomers say many, many more pass by undetected. This year alone, scientists have discovered more than 1,500 NEOs, the Christian Science Monitor reports. That number doesn't mean that the end of days is coming—it just means scientists are getting better at detecting and monitoring objects that come into our celestial neighborhood. While the new "Scout" system looks at smaller objects, NASA's older, heavy-duty "Sentry" system looks for big, far-away asteroids which might pose a threat to Earth. And if any are ever detected? NASA and the ESA are jointly working on a method to re-direct large asteroids.