The recent 10,000-ton meteoroid explosion over Russia has been a sensation. This provides tangible proof that there are violent threats in space. Such a meteoroid traveling at sufficient speed (i.e. 18 kilometers per second) packs the punch of several atomic bombs. If a potentially hazardous asteroid such as the one named Apophis (only some 300 meters in diameter) were to hit Earth it would have the explosive power of 30,000 atomic bombs and could wipe out the entire East Coast of the United States. Arthur C. Clarke was fond of sharing a quote from his friend Larry Niven: “The dinosaurs became extinct because they didn’t have a space program.” The irony is this might prove true for us as well.
Unfortunately the 24-hour-a-day cable media don’t have a clue about what to do other than to play up the scare factor and then blithely go on to the next news event. It is time that the space news media and space agencies help frame these threats in clear terms and help define prioritized programs to address these dangers in terms of national, regional and globally funded space programs. The International Space Safety Foundation, the International Association for the Advancement of Space Safety and the B612 Foundation have been seeking to do this for some time. We need to amplify their message about the need to address these dangers. Here, therefore, are at least some specific steps that could be taken.
Better public awareness
Everyone understands the 1 to 10 Richter scale regarding earthquakes and most everyone knows the 1 to 5 scale for tornadoes and hurricanes, but only a few insiders are aware of the Torino scale adopted by the United Nations’ Unispace conference that explains risks and potential damages from potentially hazardous asteroids. The latest version of this scale should be widely publicized and introduced to the general public worldwide so that there is a better understanding of such space threats and the need for improved research, technology and exploration programs in this area.
A renewed and expanded NEOWISE initiative
The WISE (Wide-field Infrared Survey Explorer) space telescope launched by NASA in mid-December 2009 has been carefully mapping as many near-Earth objects (NEOs) as possible during its time in orbit as well as far-flung galaxies. In the time between its launch and its shutdown on Feb. 17, 2011, WISE collected millions of images and completed one-and-a-half inventories of the Earth’s overhead sky by a systematic scanning process. The spacecraft’s satellite infrared sensors captured some 1.8 million images. These have allowed scientists to detect 19 previously unseen comets. They also allowed the detection of over 33,500 asteroids and 120 previously unknown NEOs that could become potential hazards to Earth. The infrared sensors that detect radiation outside the visible light range were able to detect low-heat “brown dwarf” stars and objects that might be invisible due to dense dust cloud layers and other obscuring elements.
The $320 million project was certainly successful in living beyond its projected 10-month mission lifetime. Ultimately it was exhaustion of the coolant for the infrared sensors that was the limiting factor. By cleverly shifting from a four-sensor operation to only two the lifetime was extended. After the coolant was entirely expended, a further program called NEOWISE was undertaken for three months up until its February 2011 end date. During this NEOWISE phase, the spacecraft was entirely devoted to searching for near-Earth objects. But this task still remains far from complete. A new jointly funded project that is optimized for identifying undiscovered NEOs is clearly needed.
Key research initiatives
These would range from a better understanding of the so-called keyhole effect that can change the orbit of potentially hazardous asteroids to directed research to understanding how asteroids might be diverted from a direct impact. There are a variety of techniques under study. These include using gravitational force or explosives to divert asteroid orbits or, on shorter-term time scales, nuclear demolition. The European NEOShield program is well focused on this research but its current budget of only 4 million euros ($5.2 million) over a four-year study period is woefully inadequate.
A comprehensive research and exploration program for all forms of space threats
The truth is that we are vulnerable in many ways: solar flares, coronal mass ejections, and now new concerns about “cracks” in the Earth’s geomagnetic field that are lessening the protective shield of the Van Allen belts. A unified global space program to help protect humanity from all known threats from space needs to be developed along with climate change mitigation efforts. Unless we act, we may find we are not really smarter than the dinosaurs after all.
Joseph N. Pelton is immediate past president of the International Space Safety Foundation and author of the forthcoming “Orbital Debris and Other Threats from Space.”