Your reminder concerning death from above
July 20th, 2008
By JAZZ SHAW, Assistant Editor
The conference on Global Catastrophic Risks is meeting in the U.K. this week, and Reason Magazine provides a rundown of the major threats we face from outside the planet, and more to the point, what industrialized nations like ours are doing about it.
In 1998, Congress charged NASA with surveying the skies to detect 90 percent of near earth asteroids (NEAs) greater than 1 kilometer in size in 10 years. An impact by a kilometer-sized asteroid could end civilization. Besides the blast, such an asteroid would inject so much dust into the atmosphere that it would cause global winter that would cause massive crop failure.
Proposals to have the Spaceguard Survey expand to detect NEAs as small a 100-meters are now being considered. Morrison groused that NASA has spent only $ 4 million on Spaceguard and argued that the magnitude of the risk merits a budget of half a billion dollars.
The study is dealing with three specific types of threats. The first is is the meteor problem. We haven’t found any dinosaur killers coming our way any time soon. Of course, while a one-kilometer-or-greater diameter meteor strike would end civilization, if not drive us to extinction, considerably smaller objects could wreak major havoc. We’re still a long way from identifying all of the potentially-dangerous objects down to the 100 meter range, which would impact with a force greater than the largest nuclear bomb in our possession.
The second threat they study is that of a massive Gamma Ray Burst (GRB) which could be generated by a star in this part of the galaxy going supernova. It could effectively put the planet inside a microwave oven for a while and would be catastrophic. Sadly, there’s not much we can do about that if WR-104 decides to blow up on us.
The last threat is from comets. We tend to have a pretty good grip on the icy comets from the Kuiper Belt (out near where Pluto orbits) such as Halley’s. What this team is more worried about are rocky, “dark comets” in long-period orbits coming from the Ort Cloud. They only show up rarely, but do so with little warning and don’t have the flashy tails that their Kuiper cousins display. They remind us that the IRAS Araki-Alcock dark comet came zooming by in 1983, missing us by an astronomical hair’s breadth, and we didn’t even see it until it was two weeks out.
Congress is once again talking about trimming NASA’s budget for next year as everyone rushes to “fix government spending” during and election year. If cut funding for near earth orbiter studies and protective programs like Spaceguard, the good news is that you may only have a month or so to regret the decision. Keep that in mind while voting.
This entry was posted on Sunday, July 20th, 2008 at 7:06 am and is filed under NASA, Science. Both comments and pings are currently closed.
