Asteroid Eros
Image: Courtesy of NASA/Goddard Space Flight Center's Scientific Visualization Studio
Over the past couple of years the U.S. space program has gone through a huge shake-up, leaving the nation’s goals in space unclear. I have a suggestion. NASA, working with other national space agencies and private organizations, should take on the job of ensuring that no destructive asteroid ever hits Earth on our watch. What project is more worthwhile in the long term or awe-inspiring in the short term than protecting humanity from ruin?
At first glance, asteroids may seem like a distant threat. But the hazard is well documented, and the consequences could not be more severe. The history of life on Earth has been shaped by asteroid impacts. One million of them wider than 40 meters in diameter orbit the sun in our vicinity, by some estimates. An asteroid of that size struck Earth over Siberia in 1908 and laid waste an area 150 times larger than the Hiroshima atomic bomb did. The odds of a repeat in this century are about 50 percent. On the larger end, asteroids greater than about one kilometer across would have global effects that threaten human civilization.
The first step in prevention is prediction. We must find, track and predict the future trajectory of those million near-Earth objects. Astronomers have already catalogued the orbits of most of the kilometer-scale objects they think are out there, and none are known that will hit Earth in the next 100 years. Yet the great majority of smaller ones, those big enough to destroy a country or unleash a tsunami that devastates coastal cities, remain untracked. This unfinished business should be tackled next.
Asteroids are warmer than the background sky and therefore stand out in the infrared. Telescopes have blind spots, however: they cannot look in the direction of the sun, which limits the effectiveness of telescopes stationed on or near Earth. The National Research Council recommended in 2009 that NASA place an infrared survey spacecraft in a Venus-like orbit around the sun. As it looked outward, away from the sun, the observatory would spot asteroids that go unseen from Earth. Once completed, such a survey would remain valid for about a century—the timescale on which the measured orbits begin to change because of gravitational interactions with planets—before we would have to do it again. The cost of such a mission would be several hundred million dollars—expensive, to be sure, but a bargain compared with NASA’s current budget, let alone the damage of an asteroid strike.
Should astronomers find an asteroid on a collision course, our task would be to reach out and alter its orbit to prevent that impact. If we find the asteroid early enough (decades ahead of its projected impact), several existing technologies might work: tow it, ram it, nuke it or employ some combination. (My colleagues and I used to advocate pushing on the asteroid with a rocket [see “The Asteroid Tugboat,” by Russell L. Schweickart, Edward T. Lu, Piet Hut and Clark R. Chapman; Scientific American, November 2003], but recent results on asteroid properties and orbits have made us reconsider.)
Yet no one is really sure whether these options would actually work. Surely the time to test them is before they are needed for real. NASA and other organizations should build and try out a system to deflect a nonthreatening asteroid in a controllable way. Given that astronomers have not even begun a complete asteroid survey, there is a real risk they will find an incoming asteroid before we have time to do a dry run. So this work must begin now. It would not take large increases to NASA’s budget.
All civilizations that inhabit planetary systems must eventually deal with the asteroid threat, or they will go the way of the dinosaurs. We need to predict in advance when impacts are going to occur and, if necessary, shift the orbits of threatening asteroids. In effect, we must change the evolution of the solar system.
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22 Comments
Add CommentGiven that throughout history humanity has spent much of its time and effort on activities resulting in demise or others, be it people or species, it would seem only right to have a tiny little investment into something which can actually prevent our own extinction... or at least reduce the risk of it coming from the skies. The fact that this is not yet part of NASA's charter is frightening... and seems a lot more worth-while than other NASA or human endeavors.
Reply | Report Abuse | Link to thisI would suggest another "global" use of astronautical knowledge and technology. In short, this is fighting the hurricanes. Hurricanes start when the temperature of the sea water rises up to a cpecific level. If I am not wrong, it is about 80F. To prevent water from heating up to this level, a kind of umbrella should be placed in the sky. It may be made of some dusty material, which reflects or otherwise prevents sun heat. The cloud of this material (may be hundreds miles in extent) should be placed on a geliostationar orbit above the most critical spots on Earth, for example above Atlantic Ocean between Africa and Americas. Implementation of this project will prevent people from great damages caused by hurricanes. The environmental aspect of this project should be considered, certainly.
Reply | Report Abuse | Link to thisIn my previous comment, I should say "geostationary orbit" instead of "geliostationary". Sorry for this mistake.
Reply | Report Abuse | Link to thisWe should put a TRANSPONDER on one if it is found to be a near-earth object. That way, we can get a precise orbit.
Reply | Report Abuse | Link to thisOtherwise we won't know exactly WHERE it will strike the earth.
Regarding the Jellostationary orbit: Is that lime or strawberry?
Reply | Report Abuse | Link to thisAtlantis is supposed to pop up after an asteroid hit. An asteroid 1 mile in diameter.
Reply | Report Abuse | Link to thisEverytime I see an article about Asteroids and preventing them from hitting the Earth I think it has to be a joke. The time and effort and expense would better serve people in the here and now than try to prevent something that has happened and will happen again. Not only would you have to prevent strikes on the Earth but the Moon as well. The number of potential Rocket failures and massive size of the equipment involved should make a prudent person think twice about the effort. But for some reason we always think we have to do "something". Keep it on the Earth. Interplanetary colonization is another dream that keeps people dreaming but is also impossible and impractical.
Reply | Report Abuse | Link to thisThe problem is not that an asteroid could be coming towards us at some future time. The problem is that in all probability when the day comes for us to be hit, it won't be by a single asteroid but by hundreds or even thousands of them. The Apocalypse speaks of "stars falling down on Earth from the sky".
Reply | Report Abuse | Link to thisWith all due respect, everytime I read a comment like yours, I think it has to be a joke. We should be doing anything that might ensure our long-time survival as a species. Especially because at this moment we have the ressources and the know-how needed to start a project like that, and succeed. Why wait ? Tomorrow could already be too late.
Reply | Report Abuse | Link to thisThe ''here and now'' mentality you refer to is currently the problem of our society, focused on trivial details instead of looking at the big picture. What a lack of vision and ambition !
What's important is to KNOW exactly WHERE it will hit.
Reply | Report Abuse | Link to thisIf it's reasonably small, and not near any large populated areas, we could ignore it or set up a warning.
If a lot larger, then a nuke would probably take care of it.
The Apocalypse speaks of "stars falling down on Earth from the sky".
Reply | Report Abuse | Link to this--
Yes, but that refers to a cataclysmic bombardment of Kim Kardashian publicity garbage. Neither one is pleasant.
I don't know whether to laugh or cry.
Reply | Report Abuse | Link to thisThe secular materialists will continue to believe, regardless of evidence, that this planet is merely subject to random "darwinian" chaos.
However, if anybody has EVER looked at DNA-STRANDS, sacred geometry, the elegance of Physics and Chemistry, one must realize there is a HIGHER Intelligence at work.
If an asteroid shows up here to obliterate the Corporate, indemnified, insensate part of humanity, it's probably because Corporatism is in the HABIT of obliterating Life and needs to be eradicated like a VIRUS OR DISEASE--which happens at this point to be true at the moment.
Secular materialism is a disease.
Another 1859 Carrington event would be similarly disastrous and seems another preventive regarded as low priority. Or a global weirding affecting agriculture and the thermohaline current. Or the end of the Euro. Or a Republican takeover of judicial, executive and legislatative branches. Let's not be so mean spirited here, there's lots more!
Reply | Report Abuse | Link to thisLet's be realistic. When the day comes to be hit, it won't be by one but maybe by hundreds or thousands of them rocks.
Reply | Report Abuse | Link to thisLet's be realistic. When the time comes to be hit, it won't be by just one rock but maybe by hundreds or thousands of them.
Reply | Report Abuse | Link to thisPeople who believe in the blind violence of a random universe carry with them the seeds of inaccountability for the results, effects and outcomes they create; which means, they're law-less people (except if it's convenient).
Reply | Report Abuse | Link to thisA threat, yes, but we don't appear to have the technology to do anything about it? Chances of a planet killer/very large rock striking Earth in the next 100 years? I believe in getting out into space but we have far more pressing concerns on Earth. It is simply much more likely we'll do more harm to humanity than a planet killer hitting Earth in the next 1000 years.
Reply | Report Abuse | Link to thisGood point, gmperkins. So, let's stop harming ourselves in the name of profiteering.
Reply | Report Abuse | Link to thisThe idea of protecting ourselves from extinction this way is not new but it is long overdue to be actualized. What's amazing is the resistance to it, which seems to boil down to either 'the money could be better spent elsewhere' or religious nutbaggery. To answer the first objection, creating and maintaining a space-based infrastructure would be a very good way to divert existing resources from warmaking without wrecking the economy even worse than it already is (the wars we're presently engaging in being huge parts of the economy that are usually not discussed in the context of being essential to prop up for that reason alone). It would thus allow us to transition from war to peace without economic damage AND provide real warning and possible protection in the event of a large rock actually heading our way.
Reply | Report Abuse | Link to thisThere is no good answer to religion-based objections though, as religious nutbags are always certain they are right and understand the world perfectly, despite the fact that history has proven them wrong again and again. There's just no convincing the delusional that their delusions are in error. So those we will have to live with, and work to overcome, as usual, for civilization to make any real forward progress.
Maybe they could fix the Low Earth Ruble Orbit thing first?
Reply | Report Abuse | Link to thisOr, unemployment (start with Astronauts).
Then, with a track record established, they could SAVE the F'n World. Later, maybe. Maybe.
"Secular materialism is a disease" - said one contributer.
Reply | Report Abuse | Link to thisWhy should we oppose science and religion?
They have separate domains. Science doesn't have ethics, but religion does. Religion cannot explain and predict nature and nature's phenomena, but science can.
Scientist may be a religious person (Gregor Mendel, a monk).
Any religion is only a code of laws for human behavior, not a code of laws of physical nature.
Reply | Report Abuse | Link to thisWith reference to "Stop the killer rocks" by Edward T Lu.
In all the years I've watched the night sky and seen meteors as bright streaks.On 23rd Sept 2010 i, and my girlfriend at the time, witnessed the greatest natural event we have ever seen. It was a clear night with a bright moon to our left and just one large cloud above our heads and a clear sky to our right. We were in Burslem Park, Stoke-on-Trent, England,overlooking Port Vale football ground,walking the dog (Molly).As i Was looking at the sky towards Vale Ground on my right,all of a sudden there was a disturbance in the atmosphere. A ball of disturbance with a bow wave. In a split second i saw a large meteor as plain as could be, along with 6 or 7 pieces that had broken off,these too were quite large and easy to see as they started to glow pink and then disappear behind the cloud above our heads. They were so low we felt the pressure waves from the tumbling effect as they passed over and they cast shadows on the underside of the cloud above our heads. I said to my girlfriend that the shadows looked like a flock of geese flying from one side of the cloud to the other.These pieces of rock were big and came in low,were plain to see and we felt their effects.We thought then that it could just as easily come in at a steeper angle and within a split second we, and the whole of Stoke-on-Trent could have been wiped out. It is a real possibility that this could happen. The disturbing thing is, although we are close to Jodrel Bank in cheshire, there has been no mention by anyone or any media of this been seen by anyone else. I have told many of my friends of what we saw but no one of importance, until telling you now.
Edward T Lu is right, we need to do more to predict when impacts might occur. It could so easily have happened that night in Stoke-on-Trent.
Thanks For the Article.