Today we can all breathe a little easier thanks to a new survey of near-earth asteroids by NASA's Wide-field Infared Survey Explorer (WISE). After a year of scanning the celestial sky with infrared light between January 2010 and February 2011, the study has shown there are significantly fewer mid-size near-Earth asteroids than thought. That's not even the best news.
That best news? The study — called NEOWISE — is believed to have found 93% of the largest near-Earth asteroids.
NASA took pictures of virtually everything in the sky — from galaxies to comets and the near-Earth asteroids. Data was captured on over 100 thousand objects in the prime location between Mars and Jupiter — the so-called Jupiter Belt. It's the most accurate census of these asteroids orbiting within 120 million miles of the sun, and into the Earth's vicinity. The study was more effective than previous scans of the sky due to the upgrade to infared technology that can detect both light and dark objects since it senses heat rather than visible light. It seems sometimes those pesky asteroids like to hide in the dark.
This new development in telescope technology logged approximately 19,500 mid-sized (between 300 and 3,300 feet wide) near-Earth asteroids instead of the previous estimate of 35,000. 585 are known to be lurking in the near-Earth vicinity and while scientists are still researching what this means for an Earth-asteroid collision, we're thinking we like the improved odds.
Even more encouraging is the data on the larger near-Earth asteroids — those over 3,300 feet in diameter. Scientists revised the estimate of these space-traveling behemoths from 1,000 down to 981 — of which 911 have been mapped in the sky. Experts say that none of these are expected to threaten the Earth within the next few centuries — fortunate for us since it believed one as big as 6 miles in diameter was responsible for ending the age of the dinosaurs.
This data, mapping out more than 93% of the near-Earth asteroids betters the 90% goal mandated by Congress back in 1998 as scientists recognized the implication of an Earth strike. The effort became known a project "Spaceguard." The NEOWISE data complements ongoing ground observer efforts and will continue to keep an eye on the sky.
While the news is resoundingly positive, the fact remains that these space rocks are still out there. Mid-sized asteroid could cause some global mayhem if it hit in the wrong place, and even a small one could rock our world. It's an interstellar case of "know thine enemy," "be prepared" and all those other little sayings you learned in Scouting.
Via Science Daily