Ideas and Opinions
The Sky is Falling: the deadly threat posed by Near Earth Objects and what we can do about it
Washington, Jul 21, 2008 - On June 14, 2002, the Earth narrowly avoided a deadly event. One which quite possibly would have had a devastating effect on the course of humankind. The close call came and went, and for three days nobody noticed that day a football field sized asteroid careening at 6.2 miles per second came within 75,000 miles of hitting the Earth. Three days later the asteroid was discovered, but of course by then it was far too late. Had the asteroid hit the Earth, the devastation may have equaled the 1908 Tunguska event, an asteroid or comet that flattened over 80 million trees in a remote region of Siberia. .
A variety of bodies have been orbiting around the sun since the early beginnings of our solar system. They range in size from small dust particles to near planet sized behemoths. For the most part, these objects stay within two large bands orbiting the solar system, but many others take less predictable paths. Some take them closer to the planets like Earth earning their designation as a Near Earth Object, or NEO.
These heavenly objects are of course nothing new to most Americans. As children many laid out in the summer fields to watch the Perseid or Leonid meteor showers streak across the sky, and a new generation has been introduced to NEOs through various movie adaptations such as Armageddon and Deep Impact.
But it is vital for all of us to realize this is not just for the movies or science fiction. The threat of an asteroid hitting the earth is a serious matter. It has been well documented that the Earth's moon and many other planetary bodies in our solar system are covered with impact craters. Most people have heard of the dinosaur extinction theory or perhaps seen pictures of the meteor crater in Arizona. However remote the possibility of an NEO striking the Earth and causing a worldwide calamity, no matter how obscure that may sound to some, is still a calculable threat.
During my tenure as chairman of the House Subcommittee on Space and Aeronautics, NEOs became one of my main priorities. I was consistently astonished by the utter lack of preparation in detecting and defending against such objects.
As a result, I’ve offered several pieces of legislation to advance the detection of NEOs. In 2005, I authored H.R. 1023, the “Pete Conrad Bill,” which passed the House of Representatives but regrettably did not pass the Senate. The bill was a tribute to Astronaut Pete Conrad for his tremendous contributions to our country and the global aerospace community over the last four decades. Conrad exemplified the American spirit as a pilot, explorer and entrepreneur of the highest caliber, but he’s most often remembered for commanding Apollo XII where he became the third man to walk on the moon. His historic description of the Moon landing will be forever be a part of American history. The bill honored Pete Conrad by establishing an annual astronomers award for future asteroid discoveries in his name.
During the current session in Congress, I introduced HR 4917, the “NEO Preparedness Act,” which if passed establishes an Office of Potentially Hazardous Near-Earth Object Preparedness. The office would coordinate with other agencies a readiness plan in the event an NEO collision was detected.
I’ve also supported an increase in funding for the continued operation of the Arecibo Observatory in Puerto Rico because the unique radio astronomy and planetary radar capabilities of the facility are the most powerful in the world for tracking NEOs.
To date, limited action has been taken to address this threat. I’ve strongly supported a joint operation undertaken by NASA and the Jet Propulsion Laboratory to detect NEOs, called “Safeguard.” JPL has catalogued and charted the orbits of nearly 90% of known NEOs over one kilometer in diameter, yet, gaps still exist. For example, it is nearly impossible with ground based telescopes to detect asteroids in daylight, hindering our ability to identify NEOs in a timely matter. This is an enormous undertaking the United States should not be tackling alone creating serious challenges without international cooperation.
As we continue to work with the global community on the International Space Station, we should also work with our Russian and European allies to expand our ability to detect NEOs. Sheer numbers tell us this is an endeavor we will be unable to complete ourselves. JPL’s recent effort to catalogue 90% of NEOs over 140 meters in length by 2020 has yet to begin, and even then that search will not include objects the size of the Tunguska event. Most distressingly, NEOs are often discovered only days before or after passing by the Earth. To undertake this Herculean mission, data should be shared in concert with other countries willing to use their own resources to analyze collected data. Additionally, the RT 70, a Russian radar and observatory, although less powerful than Arecibo, can also assist in the discovery of NEOs.
If we look at asteroids from the perspective of our national goals in space, they present not just a threat but also unique research opportunities. In terms of pure science, asteroids are geological time capsules from the era when our solar system was formed- made up of orbiting mines of metals, minerals, and other resources that can possibly be used to build large structures in space without having to transport materials from Earth.
So far NASA has successfully surveyed hundreds of asteroids representing only a fraction of the projected total population of asteroids and near Earth objects. The time is now to begin to fully understand NEOs and prepare for their potential worldwide threat before it’s too late.