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Researchers are looking into the possibility of sending a swarm of "laser bee" satellites to deflect a potentially hazardous asteroid, as shown in this artist's conception.
How do you solve a problem like Apophis? For years, researchers have been tracking the asteroid to determine whether or not it could get into a catastrophic smash-up with Earth on Friday the 13th in April 2036. Last week, Russian reports suggested that Moscow is thinking about launching a probe to Apophis as early as 2015 to track the threat, but U.S. experts say it's the wrong idea for the wrong asteroid.
So what's the right idea? They have a modest proposal that just might save the planet someday.
First, here's a little more background on Apophis: The 885-foot-wide (270-meter-wide) space rock was discovered in 2004 and set alarm bells ringing when experts said it had a 1-in-40 chance of hitting Earth in 2036, due to the uncertainty about its orbit. Since then, astronomers have gotten a better fix on Apophis' parameters and set the chances of collision at 1 in 240,000 or so. Some uncertainty remains, because if the asteroid passes through a relatively small region of space known as a "keyhole" in 2029, Earth's gravitational pull would deflect its course just enough to guarantee the hit in 2036.
Last week, the Russian Academy of Sciences recommended sending a small, radioisotope-powered probe with a radio beacon on board, so that astronomers could get a high-precision fix on Apophis' trajectory. "From a technical point of view, the mission could be started for implementation from 2015," the academy was quoted as saying by the RIA Novosti news service.
I ran that idea past several experts on the asteroid threat, and the consensus was that you almost certainly wouldn't need that kind of mission to rule out a collision threat. Retired astronaut Rusty Schweickart, who has become deeply involved in studying potential threats from near-Earth objects and how to address them, noted that there's an excellent opportunity for high-precision, Earth-based observations of the asteroid coming up in early 2013. Another opportunity comes along in 2021. Chances are that the upcoming observations will turn Apophis into a complete non-threat.
"Why, given this circumstance, the Russians would send a probe to Apophis in order to pin down its impact probability is indeed puzzling," he told me in an email.
Scientific value
That's not to say a trip to Apophis would be totally useless. Far from it.
"I would support a mission to study Apophis, either a lander or an 'orbiter' rendezvous mission," David Morrison, director of the SETI Institute's Carl Sagan Center for Study of Life in the Universe, wrote in email. "I wish the Russians luck. This fascinating object is a favorable target mostly because it will come so close to Earth in 2029, so that ground-based observations can be made in synergy with in situ measurements."
Clark Chapman, a planetary scientist at the Southwest Research Institute, agreed that there are plenty of good scientific reasons for studying Apophis up close. "It is expected that the tidal effects on the body could change its characteristics markedly ... and I know a number of colleagues who would like to see such a mission," Chapman wrote. But based on RIA Novosti's report, the kind of mission that the Russians are contemplating may not fill the bill. In fact, it could do more harm than good.
"I wouldn't totally dismiss the concerns about physically interacting with Apophis during its close approach," Chapman said. "If a spacecraft were actually to dock with it, there is the possibility of interfering with the natural responses that are of interest ... and, in the extremely low-probability case that Apophis were right at the threshold of passing through a keyhole, tampering with it could raise legal issues. I'm not aware that anyone has deeply thought through these concerns."
The right target
All three of the experts are giving deep thought to another potentially threatening asteroid, a 460-foot-wide (140-meter-wide) rock that's been designated 2011 AG5. Right now, the rock has been given a 1-in-500 chance of hitting Earth on Feb. 5, 2040, due to the uncertainties about its orbit and its location relative to a cosmic keyhole in 2023.
Schweickart has been calling on NASA to start making preliminary plans for a mission to 2011 AG5, just in case we need to get a better fix on its orbit between now and 2023. If observations over the next couple of years eliminate the possibility of a threat, hallelujah! But if they don't, and if we're still worried about AG5, we'll have a head start on the asteroid deflection campaign.
"So it would seem that Russia is heading toward the wrong object!" Schweickart wrote. "There could hardly be a better example of the need, not currently in place, for international coordination when it comes to NEO [near-Earth object] impact analysis and deflection planning. So why aren't we?? Ask NASA. Please."
Chapman had a similar assessment: "I agree with Rusty that precisely determining the orbit of Apophis seems like a low priority at this time. And I also agree that, as of now, 2011 AG5 is the near-Earth asteroid of interest."
Back in February, NASA's Jet Propulsion Laboratory issued a statement noting that there'll be good opportunities for observations of 2011 AG5 in late 2013 and late 2015. "I fully expect we will be able to significantly reduce or rule out entirely any impact probability for the foreseeable future," said Don Yeomans, manager of NASA's Near Earth Object Program Office.
Zapping vs. whacking
Even if Apophis and 2011 AG5 turn out to be totally harmless, it's not such a bad idea to have the plans for a "reference mission" to a worrisome asteroid ready to put into effect. And if it turns out that a future asteroid really is on a collision course, what should we do about it?
That brings us to another angle in the debate over near-Earth impacts: Some have suggested sending in the nukes. Others have proposed launching a "gravity tractor" to shepherd a threatening asteroid into a non-threatening orbit. Researchers at the University of Strathclyde in the Scottish city of Glasgow have been working on a different approach: using a swarm of solar-powered, laser-equipped satellites to blast away at the rock and deflect it.
They say their system could be effective with objects that are smaller than Apophis — say, 150 feet (50 meters) across, like the object that is thought to have blasted a Siberian forest to bits in 1908.
"We could reduce the threat posed by the potential collision with small- to medium-size objects using a flotilla of small agile spacecraft, each equipped with a highly efficient laser which is much more feasible than a single large spacecraft carrying a multi-megawatt [laser]," engineering professor Massimiliano Vasile said in a news release. "Our system is scalable, a larger asteroid would require adding one or more spacecraft to the flotilla, and intrinsically redundant. If one spacecraft fails, the others can continue."
Schweickart said researchers have been talking about zapping asteroids for a few years. "I've never been able to convince myself that they've ever done any cost-effectiveness investigation ... assuming that they can actually solve the multitude of other technical issues inherent in the concept," he wrote.
It may well be that crashing one of the swarming satellites into an asteroid would have more of an effect on its trajectory than having the whole flotilla aim lasers at it, Schweickart said. In his email, he laid out the more likely scenario:
"It is difficult to take this proposal seriously when compared with the already available kinetic impact [KI] solution. About the only advantage it has over a simple kinetic impact is that it would presumably be able to execute a precise orbit change (vs. the KI approximate orbit change). However, in the last few years it has become generally accepted in the NEO deflection 'community' (such as it is!) that a gravity tractor capable 'observer' spacecraft would be pre-positioned to observe, verify, and ultimately precisely adjust (if necessary) the KI-generated orbit change. The cost, current availability and simplicity of the KI/GT deflection concept is still the 'standard' against which other systems will have to be compared... and especially re their cost effectiveness."
Morrison agreed: "What is needed for deflection is to change the momentum of the asteroid in a controlled way. Surely a simple impact by a fast-moving interceptor is the most efficient way to do that, since the spacecraft is not required to brake and rendezvous, and then fly in formation with, the target."
In a TEDx talk, the B612 Foundation's Ed Lu talks about how to deal with asteroid threats.
Former astronaut Ed Lu, president and CEO of the B612 Foundation, also cast a vote for hitting an asteroid with something, if that's what needed to be done: "I couldn't agree more with Rusty's comment about how the real-life feasibility of such schemes needs to be taken into account. The same could be said of suggestions that asteroids could simply be 'painted.'"
So it sounds as if the right course of action is to draw up the plans for a quick trip to a potentially hazardous asteroid, just in case we need some up-close reconnaissance, and working out a strategy for giving it a good whack if necessary. NASA's OSIRIS-Rex mission, due for launch in 2016, might serve as a good first step. The target for that $800 million mission is the asteroid 1999 RQ36, which has an ever-so-slight chance of threatening Earth in 2182. By then, we should have our anti-asteroid strategy well in hand. And who knows? We might even have to put the strategy into practice long before then.
Are we on the right track to avoid the dinosaurs' fate? Where would you rank the asteroid threat on your list of worries? Feel free to register your opinion in the vote above, and/or the comment space below.
Update for 1:40 a.m. ET April 13: I've made a few tweaks to the story in consultation with Schweickart. In an email, he said a successful asteroid deflection campaign requires two missions: first, an observer spacecraft to monitor the asteroid's position, and then a kinetic impact spacecraft to do the whacking:
"The observer spacecraft is more properly designated a 'transponder/gravity tractor' spacecraft ... the gravity tractor being potentially needed to adjust the NEO orbit slightly after the KI impact. Not either/or, but both/and. There should never be a KI deflection without a transponder/GT spacecraft in place before, during and after the KI impact. It's both/and."
Got it? On it!
More about asteroids:
- Asteroid debate rises to next level
- To fight off asteroids, humans must cooperate
- Largest digital camera hunts killer asteroids
- Here's how to counter a killer asteroid
- Interactive: Close encounters of the asteroid kind
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Leave a Comment:
It's pretty cool how we now know so much about the threats of the asteroids , sizes , shapes and possible paths of the few we are concerned with ....
But I think it's still like going through bear territory and avoiding the ones you see ....
It's the bears you don't see that you need to be concerned about ....
These ideas of keeping asteroids from harming Earth appear to be doable , unless they find one like the size our moon coming at us ....
Specially with today's technologies and weaponry ....
Thanks Alan ....
Many small asteroids like items are already floating around earth. We call them Space Junk. If NASA and friends were serious about deflecting asteroids, they would have already safely deflected all that Space Junk back toward earth with the proposed laser technology. With practice, NASA and friends will become expert at deflecting small objects before the big one arrives. Space powers could probably deflect those Space Junk toward earth right now. Why is it not done?
When you deflect the junk back towards Earth, you have to avoid hitting the useful satellites in orbit and you have to worry about what doesn't burn up on re-entry and where it will hit Earth or ocean.
@ Paul-977599
most of the space junk in orbit wouldn't pose a threat to surface dwellers on earth (most are tiny pieces like screws and small chunks of aluminum/insulation from spacecraft and the satellites everyone uses are already positioned in a manner to avoid this debris
did you just ignore the bit about hitting the other useful satellites? When those two bodies collide at 25.000 mph, even more junk is created which can fall to Earth in a haphazard manner. If we are going to deflect junk downward towards Earth, we have to start with the stuff in lowest orbit altitude to avoid as much chance of inadvertant collisions as possible. The existing satellites are positioned to avoid the junk as they remain in their existing orbits. When you alter the orbits you have to know whose paths you are crossing and at what time they are crossed. If the deflection goes wrong, you could create a major snafu.
[from my own post]
I did not ignore your post.
The satellites in use today are positioned away from the debris. NORAD and a few other groups around the world carefully track most of the orbiting mess and help to coordinate with sat-operators to keep their hardware safe.
The problem is that there's just a whole lot of junk floating around in odd orbits (the Chinese didn't help with this either) that are using up valuable orbiting real estate that could be better served with working spacecraft instead, not to mention the cost of maneuvering craft out of the way every time errant junk moves through.
I think we are arguing for the same things.
Space junk is a problem? Yes
Should we take care of it? Yes
Most space junk in orbit is a threat to satellites? Yes
Is most space junk in orbit a threat to people on Earth? No
How's that?
Alan
I see nothing wrong in sending a small lander to Apophis, as long as it is done safely, one of the benefits of doing this is to try an land a small lander on such a small target. Think of it, Apophis is only 885 feet wide, putting a lander on this small rock would be a great achievement just in itself.
Have a good day Tom And Lyn.
The problem with nukeing an asteroid is the physics behind a nuclear blast. There is really no way to direct the blast wave, because there is no blast wave. The blast wave on earth uses the atmosphere to do the kinetic damage. simply put, no air, no blast wave, very, very little if any effect. To do any damage, or force a movement you would need to have a blast so big, you would need a Saturn V rocket to launch the thing, with no guarantee. A laser, most likely not, what about a graser? highly focused gamma ray blasts, or pulses over a period of time to deflect the orbit? Comments are welcome.
Just for the fun of discussion. The biggest problem is the bear (as mentioned elsewhere) we don't know about. So likely we'd be stuck using what we have (nukes) and throwing it together quickly, unless the Ruskies somehow knock it toward us. Fortunately, our orbit has been mostly cleared and the moon helps.
Wasn't the problem with nuking it discussed in the movie Armageddon? You probably would actually have to drill into it and blow it into bits vs. redirecting it, assuming that it's small enough to do that. Problem with that is assuming that a large chunk isn't metal that will be propelled by the blast closer to being a direct hit. Gamma ray blasts would have to be incredibly strong do we have that capability?
If it's too large then were probably screwed.
Something as powerful as the Russian Tzar Bomba (100 Megaton H-bomb tested in 1961) would probably evaporate the whole asteroid by the heat radiation; no atmospheric blast wave needed. Back then, the device weight was some 27 tons; most likely modern technologies would cut the size and weight in multiples. Probably even the technology of today is capable to deliver the bomb; by 2036 the technology will be even more capable.
Even if the whole thing will not be evaporated, the explosion of that scale will definitely change its orbit sufficiently enough to avoid the impact.
I guess grounding it is out of the question.
Don't be afraid of asteroids just because it is an asteroid...that's racist!
"Give it to Mikey, he'll eat anything!'
There might be a lot of scientific knowledge to be gained by landing a radio beacon to do in-situ measurements in addition to Earth Based observations.
For one, we know that in many cases, trajectories and equations, while good, are not exact as you project into the future once you add in three bodies (i.e., Poincare's Three Body Problem). The limitations of the equations tested with data from a radio beacon would allow us to measure the error in the predictions which may help to refine the equations in the future or give us an indication of what probabilities we can give to future predictions.
Of course, we would not want to have an accidental collision with the asteroid in that any alteration of course in 2012 might put it on a trajectory for a 2036 hit if it might have missed...this concept would be similar to the Butterfly Effect in which a small nudge or alteration in trajectory now might take it on a wildly different path in the future.
I would think that if we did land a beacon now, and kept track of the trajectory, at the same time, between now and 2036, development of methods to prevent the asteroid from hitting could be developed. It's not like the Earth will never need these technologies as we have many cases in Earth's geologic history of asteroids hitting in the past (e.g., what would we do if the 1908 Tunguska event was going to happen today and the most likely impact area was a major US city?). So, developing the technology to deal with such an event sooner than later is prudent.
Lastly, did the scientists who named the asteroid get the name from the movie and tv show Stargate because they were fans of the show or did they come up with the name independently based on the fact that Apophis also called Apophis the Destroyer, an Egyptian mythological demon and god of chaos?
Seems like if we are going to mess with asteroids to test how we could deflect them, we ought to pick relatively small one that poses no real threat if it entered the earth's atmosphere. If done right, the results could be scaled up if necessary for a real threat. The problem I see with playing with larger ones, is unintended consequences. Namely influencing something that was destined to miss in such a way as to increase the threat.
Using the kinetic impact idea sounds like the simplest method with far less things to go wrong. Relatively low tech idea which means they could be quite a bit cheaper than some of the more elaborate ideas. It could be tested on a small scale with a small asteroid with the effects closely tracked. A small fleet of these of different sizes could be built and put into standby storage such that they could fairly quickly be made ready for launch. We are at a point where anything of a dangerous size could be detected with a reasonable amount of warning. A small defensive arsenal sitting around waiting would be far cheaper than trying to create some constantly orbiting defensive "sheild" or quickly trying to assemble some large elaborate solution in a short time period.
The kinetic impact idea also seems like the most easily scalable approach. Mass and speed are the keys to the amount of energy applied. This is highly predictable. A small scale test with a no risk object can supply a lot of usable data that could easily be applied to a large object.
All that space rock deflection won't do us any good when the rock heading our way is way bigger than our planet. We need to have a long range plan, let's make space our home, ASAP.
It'd be highly unlikely that we would encounter such a rock unless it was a rogue planet. The biggest asteroid that we know about is 2 Pallas (unless you want to count Ceres, which is considered a dwarf planet). 2 Pallas is only about 550 kilometers in diameter and poses no threat.
However I understand where you're coming from. We need to get out into space soon, because if a massive asteroid isn't what does us in, it'll be us ourselves.
There is no need to point out that we are speeding in space, mostly blinded, with tons of materials racing in multiple directions. I am not sure that we know exactly where we are, and in our end, there is no one at the wheel. I.E. Aside from rogue planets, we are in a collision course with another galaxy, and let us not mention that we are less than a grain of sand compare to some of the biggest stars out there (i.e. those stars can send materials our way when they expode):-( Also, in space, there are multiple scenarios where humans can not survive. Future generations will have limited choices for survival in our present form. I hate to point this out, but the same features that brought us here, will most likely be the same that takes us to the next area. Our DNA, over time, is a seed. We need to make space our home, where we have a steering wheel. Those of us that can not make it into space, need to sit back, relax, and enjoy life to the fullest, because in the end, the chances of survival in space are pretty much the same as it is on this planet:-)
If I'm not mistaken, we are already colliding with a smaller galaxy.
Long range IDEA for NASA and world powers:
Science has open our eyes, now we all know what is ahead. It is not the time to lay down and wait for something to hit us. If we are going to go, at least let us go out fighting. Let's make space our home; set up defenses in space ASAP.
NASA and the rest of the world need not only think on defending earth; a badly damage nearby planet could also cause havoc here. We should be looking at defending our solar system with all available resources. This means that we need to get our defenses from materials already available in space; find useful asteroids, and planets. We can use those materials we find to set up a collision defense system of grand scale. That mission, if undertaken, will create jobs for all. At least, we will all be fighting for a common cause. It just might be a more peaceful world for us; until the end.
The method of "deflection" which I have always favored is 'inertia fireball'. This entails sending a multi-megaton thermonuclear warhead toward the asteroid aboard a large rocket, and then spinning this large rocket around prior to impact, so that the large rocket (weighing several tons) is in between the asteroid and the nuclear warhead. You would then detonate the nuclear warhead just prior to impact, thereby vaporizing the rocket and creating an inertial fireball effect which strikes the asteroid over its entire surface, thereby gently slowing down the asteroid so its trajectory no longer intersects with the Earth's orbit. This might have to be done several times, depending on how large the asteroid is, but this method has the least probability of breaking up the asteroid, just in case this needs to be done several times. For this purpose, we need to create a standing international arsenal of Deep Space Ballistic Missiles (DSBMs), for which our new Aries solid fuel booster would probably be quite ideal. - Rick Carter
(If for some reason we were unable to detect this approaching asteroid in time to use this 'inertial fireball' method of deflection, these same DSBMs could be quickly reprogrammed to strike and shatter the approaching asteroid or comet, thereby minimizing its inertial effect upon our Earth.) - RC
Where would you rank the asteroid threat on your list of worries? of course we should prepare. It's like building a straw house near a fire source and not having fire equipment to keep the flame in check. Why is there any question? We should have been prepared already.
Slightly higher that being struck by lightning. There are about 6 billion people on the planet. An asteroid-caused extinction event occurs about every 65 million years. Therefore, on the average, 92 people will be killed per year by a giant asteroid -- more than are killed by lightning. Oh, and the last one was 65 million years ago.
Re what to do about it: If we have a decade to plan ahead for an asteroid calculated to hit the Earth, the average "shove" necessary for it to miss is only a foot or two per second. A thermonuclear device could vaporize enough surface material and blast it off on one side of the object to cause considerable rebound in the other direction.
But consider this: if we only cause it to miss the Earth, its orbit may have some unpredictable changes that will cause it to come back - perhaps with far less lead time. This is what happened to the comet Shoemaker-Levy in its encounter with Jupiter in the mid 90's: One miss, a loop, then smack! A better solution would be to change its orbit so that it hits the Moon instead. That effectively eliminates the threat. It would cause a pretty meteor shower on Earth, but no danger.
There are many other asteroids that are in near earth orbit that we don't know about that could provide a similar threat - the ones that come out of "nowhere" and blind side us. Sooner or later it will happen - it's just a matter of time before an asteroid or some Tunguska type event affects a large populated area.
Its almost like Tungunska was a dress rehearsal. We were just LUCKY that it didn't hit in a populated area; what if an asteroid that size hit New York? Or Moscow? Or even off the coast (it'd create one hell of a tsunami, that's certain).
This is not Chicken Little screaming 'the sky is falling.' This is an imminent (and unavoidable) threat to our species' future. This is not theory. This is an eventuality.
welcome to obama's space where we are now under threat from rogue asteroids. thanks alot to the failure in chief!
read up on the Tunguska blast
Then report back
Yoweee!
I suggest we launch the starship"RonaldRayguns",with Comander Stickleton in charge,and Lt. Chaney as bombadier.Blow that rock away with Hot Air!
Schweickart said researchers have been talking about zapping asteroids for a few years. "I've never been able to convince myself that they've ever done any cost-effectiveness investigation ... assuming that they can actually solve the multitude of other technical issues inherent in the concept," he wrote.
yeah because rebuilding the world or any city is more cost effective,( face palm)
Stinkleton--
That is a far reach you have, I continue to be amazed at the ability that you and your friends exhibit.
i was just joking.
fyi - i'm also amazed at the ability and insanity of fringe cons and libs.
If you were joking then your sense of humor needs work ....
This matter should be top priority of the international space community. And contrary to Stinketon's idiotic remark above, NO US president has ever effectively dealt with this issue. It's an international matter; not just a US one. Any sizable asteroid to hit the earth would be a near-global catastrophe.
If we don't begin testing on asteroid diversion soon? The only thing left for us to do on Earth would be the 'place-head-between-legs-and-kiss-our-a$$-goodbye' approach (the dinosaurs tried that 65 million years ago; didn't work out so great...).
This discussion has the feel of a parapalegic attempting to whack a fly - butting the annoyance with the forehead will not deter the pest from flight. Whether we send a beacon to Apophis or AG5 is irrelevant if we can not land it on the surface of an asteroid. An important component in an asteroid deflection system is the skill to hit the mark. International cooperation will moderate costs and appreciate success. When is launch date? Let's see how well we really navigate.
Iran is also working on a space mission to Apophis to try and insure it hits the US in 2036.
They're good with Photoshop, but not that good
I wonder why Schweickart reversed his position about a probe to Apophis.
"In 2005, Schweickart urged NASA administrator Michael Griffin to start planning a mission to land a radio transponder on Apophis."
Is it because he over-hyped Apophis back when it was first discovered, and now that the chances of impact are so minute he needs a new potential catastrophe to further his NEO agenda?
Source: popularmechanics.com/science/space/deep/4201569