Millions of observers worldwide watched Friday as two giant space rocks—one scientists had their eyes on for months and one they completely missed—narrowly avoided and smashed into Earth, respectively.
The coincidence—astronomers have determined that the Russian meteor, the largest to crash into Earth in more than 100 years, and the swimming-pool sized 2012 DA14 asteroid were unrelated—has brought a renewed focus on how NASA and its partners detect so-called "near-Earth objects."
Paul Chodas, of NASA's Jet Propulsion Laboratory, says NASA and its international partners detect about 95 percent of all asteroids and meteors that have any chance of impacting Earth. But smaller pieces bombard Earth every month or so and there is still work to be done to improve asteroid detection, Chodas says. NASA has found more than 9,730 near-Earth objects and says more than 800 of them have a diameter of more than half a mile. NASA estimates that there are as many as 500,000 near-Earth asteroids the size of DA14.
Friday's events are "just a reminder that it's a shooting gallery out there and we're right in the middle of it," Chodas says. "We do a good job detecting near-Earth objects, but we need to get better at detecting smaller asteroids."
While some asteroids are detected decades before they could possibly impact the Earth, others, such as DA14, are much closer calls. 2012 DA14 wasn't discovered until February 2012, less than a year before it passed within 18,000 miles of Earth. Meanwhile, scientists in Hawaii have already determined that an asteroid known as AG5 will narrowly miss Earth in 2040, and another, 426-foot wide asteroid, known as VK187, will likely miss Earth in June 2048.
Texas Republican Rep. Lamar Smith said Friday that Congress would soon look into ways NASA could improve its asteroid detecting abilities.
"Fifty years ago, we would have had no way of seeing an asteroid like this coming. Now, thanks to the discoveries NASA has made in its short history, we have known about 2012 DA14 for about a year. As the world leader in space exploration, America has made great progress for mankind. But our work is not done," he said in a statement. "Developing technology and research that enable us to track objects like Asteroid 2012 DA14 is critical to our future. We should continue to invest in systems that identify threatening asteroids and develop contingencies, if needed, to change the course of an asteroid headed toward Earth."