National Space Society Issues Position Paper on Protecting Earth from Cosmic Impacts

On February 15, 2013, a meteor exploded over the Chelyabinsk region of Russia. The blast damaged over 7,000 buildings and almost 1,500 people suffered injuries requiring treatment. As we observe the anniversary of that event, it is important to understand its significance and specifically what it means for the United States. Millions of objects in space, including asteroids and comets, are in orbits around the Sun that cross Earth’s orbit. When they approach Earth, they are referred to as Near-Earth Objects (NEOs). Some NEOs are large enough to cause significant damage if they impact the Earth. Many such objects have struck Earth in the past, inflicting damage ranging from trivial up to and including global catastrophe. While a future large strike with catastrophic consequences is certain, we do not know whether it will happen in 150 million years or fifteen months.

The Washington DC-based National Space Society (NSS) has been a consistent supporter of actions to defend our home planet from such events. In a position paper released today, the Society focuses attention on the near-term need and the opportunity to significantly improve our ability to detect and track collision threats to the Earth. While recognizing that this is a global problem, the paper focuses on recommended actions for the United States. Additionally, NSS urges all space faring nations to add an amount of at least one percent of their civilian space budget for developing defenses against these threats.

NSS believes that the immediate task before us is to find and track NEOs large enough to cause damage on Earth. To this end, current US ground-based searches should continue, including use of the Arecibo radio telescope. The Large Synoptic Survey Telescope should be fully funded and encouraged to vigorously pursue NEO detection. The B612 Foundation’s Sentinel Project and the JPL NEOCam infra-red space telescope should be fully funded. The Society also feels that now is the time to more seriously address the detection of long period comets. Additional work should be done on NEO characterization and deflection research.

NSS Director and Space Settlement Advocacy Committee chair Al Globus summed up the situation: “We face an existential threat. We can develop the ability to remove it. There is little or no benefit to waiting. Let’s do it.”

See NSS Position Paper on Protecting Earth from Cosmic Impacts.

Near-Extinction Event in 1883 Indicates Threat from Space May Be Greater Than We Thought

NSS Board of Directors member Al Globus reports:

We have known for some time that Near Earth Objects (NEOs) are a serious threat to civilization. We also know, more-or-less, how to reduce that threat significantly at very reasonable cost. We have thought, however, that comets were much less of a threat which is a good thing, as they are much harder to deal with.

Unfortunately, it appears that a large comet may have missed Earth by only a few hundred kilometers in 1883. If the comet fragments “had collided with Earth we would have had 3275 Tunguska events in two days, probably an extinction event” [MIT Review].

We know that comet Comet Shoemaker–Levy 9 struck Jupiter in 1994. Comet C/2013 A1 is currently believed to have a 1-in-8,000 chance of striking Mars in October 2014, passing within 120,000 km. That’s close enough to endanger satellites orbiting the Red Planet.

It appears that either we are in a period of unusually frequent close encounters with comets, or cometary threats to our existence are fairly common. Defense against comets is much more difficult than against NEOs. Comets spend most of their lifetime in the far outer portions of the solar system where they are hard to observe, and when they do come through the inner solar system they are usually moving very fast, giving little time to respond even if we detect the threat before a collision.

NASA spends about $20 million/year of NEO detection, most of which pays for ground telescopes. For one percent of NASA’s budget ($160 million per year) we could have an absolutely outstanding NEO detection and deflection program. The immediate need is for an infra-red space telescope to find most of them, for example, the B612 Sentinel. As NEO defense is essential to our survival, it is a little silly, and potentially criminally negligent, that we spend orders of magnitude more money on very interesting, but much less important, projects.

Cometary defense, however, is not cheap. Detecting a cometary threat in time to do something about it requires extremely capable telescopes. Comets are dirty snowballs which tend to break into pieces making them very difficult to deflect. If further analysis finds comets to be a significantly greater threat than currently believed, be prepared to open the checkbook.