Number of Known Asteroids and Comets that May Strike the Earth Continue to Increase

With more eyes turning to the night skies, the number of known Near Earth Objects (NEOs) has been climbing at nearly an exponential rate over the last ten years. Near Earth Objects generally fall into two classes, either comets or asteroids. The known NEOs numbered at only around 1000 asteroids and comets in the year 2000. However, as of late 2011, the number of NEOs has skyrocketed to over 8000, as technology to detect these dangerous objects has increased. Some experts warn that we are still falling behind in the race to find that one object that may strike the Earth with devastating effects.

NASA notes the the number of larger objects have steadily leveled out since the early part of last decade. These larger objects are much easier for observers to detect. It the number of smaller objects that they have been find more of each year. Even those these small space objects are considered small in astronomical terms, they could cause devastation if they were to strike the Earth. NASA also notes that even though there is an ever increasing number of NEO's that may pose a threat to our planet, the chances of one of these objects ever striking the earth is also fairly remote.

Even in more recent times, there have been significant sized objects crashing into the Earth from outer space. On such impact event was the Tunguska Event of 1908. The Tunguska explosion of 1908 in northern Russia is speculated to have been caused by either large meteoroid or comet that exploded in the Earth's atmosphere on during the evening of June 30th. That explosion has been estimated to have the destructive power that ranged between 5 and 30 megatons of TNT based on the amount of damage to the forest of northern Russia. This explosive power is roughly 1000 times more powerful than the bombs dropped on Hiroshima, Japan during the Second World War. The impact area was sparsely populated, but there was extensive tree damage.

In this time of economic crisis and budget shortfalls, NASA will have a hard time reaching its goal set in 2005 to track at least 90 percent of all Near Earth Asteroids that measure 460 feet across. In a 2012 budget proposal from the Obama administration, NASA may see an additional $280 million budget shortfall. With the budget shortfalls and hard economic times, the search for Near Earth Objects may need to be taken up by other emerging leaders in space exploration like Japan, China, and Russia.

Sources:
NASA JPL
Wikipedia - Tunguska Event
Florida Today