The writer had been under the perception an asteroid collision with the earth was an incredibly remote occurrence. That it was used as a ‘scare tactic’. But after thorough examination of the subject, one should be very concerned about a possible collision. There are numerous reasons, but three major ones:
1) NEO Discovery Statistics shows many near earth objects that can easily collide with earth during orbit. Lindsey Johnson, (Near-Earth Project Manager/ NASA) said objects ranging from 460 to 3,280 feet can decimate an entire region of earth. In 8/09 only 6,000 of the approximated 20,000 objects which have this capacity for this destruction have been spotted because of a lack of funding by the federal government. Read Spaceflight Now | Breaking News | More funding needed to meet …asteroid detection mandate. Because of the lack of funding, NASA has been able to identify only 1/3 of the asteroids that could be threats to earth.
Very few remember the 6-meter Small Asteroid 2009 VA Whizzes By The Earth on 11/6/2009. It flew by just 14,000 km above the planet’s surface, and was well inside the “Clarke Belt” of geosynchronous satellites. This flyby of asteroid 2009VA was the third closest on record. Flybys we know about, at least.
But the fact that there was so little warning is troubling. 2009VA was discovered just 15 hours before closest approach by astronomers working at the Catalina Sky Survey Catalina Sky Surveys (CSS). Also on 3/2/09, 114ft Asteroid 2009 DD45 ‘nearly hits’ Earth by whizzing 45,000 miles above the Earth’s surface. NASA has a complete list of the known asteroids scheduled for close flybys.
A similar sized object slammed into Tunguska, Siberia in 1908. The impact created a blast so powerful it leveled 1,200 square miles of forest. Even though we think we have identified some Asteroids (diameters greater than 200 km), it is believed we are only aware of a small fraction of kilometer-sized asteroids that can impact earth.
2) Future earth collisions with known and unknown asteroids will happen. Asteroid 2004MN4 (Apophis) has the potential in 2036. Boris Shustov (Director, Institute of Astronomy in Russia) explains about this asteroid, “The probability of a collision with the Earth was very high… The collision of such a large body with our planet will cause great damage.” If impact occurs, it will be with a force of 2 million atomic bombs.
On July 9, 2002, the Lincoln Near-Earth Asteroid Research (LINEAR) detected a 1.2-mile-wide asteroid. Early calculations indicate there is a small chance that this asteroid may collide with Earth in 2060. While they are monitoring this new threat, the possible impact of asteroid 2002NT7 can be found on the Torino Impact Scale. On 3/16/2880, Jon Giorgini (NASA/Jet Propulsion Laboratory) calculated that there is a possibility of a 1950DA collision. Other asteroid locators include NEAR-EARTH ASTEROID TRACKING (NEAT), Spacewatch, and LONEOS Description (Lowell Observatory NEO Survey).
3) WISE: Wide-Field Infrared Survey Explorer (NASA), has spotted its first never-before-seen “near-earth” asteroid. This is the first of hundreds it is expected to find during its mission to map the whole sky in infrared light. In other words, there at least hundreds of near earth asteroids that are so dark they can’t be visibly seen by a telescope in normal light. Only an infrared sensor can detect an object that is totally black to the eye, visible only a few days before a collision.
The unnerving part of these five asteroid locators, is NASA only has detected what they believe to be only 1/3 of the potentially deadly asteroids that threaten the earth as originally stated. Now, WISE will probably find many more that we haven’t seen. That’s find, not stop.
Number of Asteroids that are known, are in the hundreds of thousands. Potentially Hazardous Asteroids (PHAs) are space rocks larger than 100m, and come closer to the earth than 0.05 AU (Astronomical Units). But PHAs can have their orbits altered slightly by close passing planets.
One can see the graph of near-earth asteroid discoveries each year is rising–and cumulative. In 2020, if the discovery rate stays linear, approximately 12,000 dangerous PHAs orbiting the sun will be known. That doesn’t count all those unseen asteroids WISE will also locate.
It’s very likely earth could see another asteroid like 2009VA which gave a whopping 15 hours before buzzing earth. For even a medium-sized asteroid that collides, things like health care, taxes, and regulations would be moot. For an Earth Sterilizing Impact with a large asteroid 10,000 MT or greater, you can bend over and kiss your butt goodbye.
Kevin Roeten can be reached at firstname.lastname@example.org