Asteroid 2013 MZ5 has just been discovered, making it the 10,000th near-Earth object (NEO) yet found. NASA scientists estimate that there are still 90,000 such objects flying around space, which could unexpectedly crash into the Earth, causing widespread damage.
Asteroid 2013 MZ5 is believed to be around 1,000 feet across - enough to cause serious damage in any are it hit were it to strike the Earth, though not large enough to cause a wide-spread catastrophe.
The new asteroid was first photographed on June 18, 2013, using the PanSTARR-1 telescope, operated by the University of Hawaii. The telescope operates on top of the 10,000 foot-high Haleakala Crater on the island of Maui.
"Finding 10,000 near-Earth objects is a significant milestone. But there are at least 10 times that many more to be found before we can be assured we will have found any and all that could impact and do significant harm to the citizens of Earth," Lindley Johnson, program executive for NASA's Near-Earth Object Observations Program, said.
Near-Earth objects are comets and asteroids that approach within 28 million miles of our home planet. The largest known near-Earth object is 1036 Ganymed, which is about 25 miles across. That giant, however, is in a safe, stable orbit that will keep it well away from Earth. The smallest such objects are just a couple of feet from side-to-side.
To pose a major threat of global proportions, a NEO must have a diameter of six-tenths of a mile or more. NASA has so far found around 1,000 NEO's of this size, but none of the ones discovered so far pose a realistic threat to the Earth. Researchers involved in the program estimate that only a few dozen of these Earth-threatening bodies still remain unnoticed. However, smaller devastation is another story - a body just 100 feet across could cause serious damage were it to land in a populated area. Officials from NASA's Near-Earth Object Office (NEOO) believe that a million bodies like that pass near our home planet, over 99 percent of of which remain to be found.
"The first near-Earth object was discovered in 1898. Over the next hundred years, only about 500 had been found. But then, with the advent of NASA's NEO Observations program in 1998, we've been racking them up ever since. And with new, more capable systems coming on line, we are learning even more about where the NEOs are currently in our solar system, and where they will be in the future," Don Yeomans, Near-Earth Object Program Office manager at Jet Propulsion Laboratory (JPL), said.
Around 1,000 new near-Earth-objects are found every year, from observations collected through the Catalina Sky Survey in Arizona, the LINEAR Program operated by NASA and the Air Force in New Mexico, as well as PanSTARRS in Hawaii.
Although 2013 MZ5 is no danger to us, there still exist many undiscovered near-Earth objects out there that could hit anytime, destroying a city in an instant.