Bad Idea: Blowing Up Asteroids with Nuclear Missiles
Written by Ian O'Neill
On 4 July 2005, NASA collided a projectile with comet Tempel 1. Should a nuclear warhead be used in the future to deflect asteroids? (NASA)
The first thing that comes to mind when someone asks: "How do we deflect a near Earth asteroid?" is "Fire some nuclear missiles at it." However, this might not be the best course of action. Akin to opening a walnut with a sledgehammer, there might be a better, less messy option. This is what Apollo astronaut Rusty Schweickart thinks at least. Last year, NASA issued a report suggesting they were seriously considering a nuclear option should an asteroid threaten Earth. However, the ex-lunar module pilot believes this decision was manipulated by political pressure, possibly indicating the asteroid threat was being used to speed up nuclear proliferation in space…
When ex-Apollo astronauts express an opinion, people tend to sit up and listen. After all, the astronauts throughout the space race years in the latter half of the 20th Century (from the USA and Russia) were the ultimate explorers, going above and beyond the call of duty, putting their lives on the line for their countries. Several of the retired Apollo astronauts have come forward over the years with their opinions on modern NASA, concerns for the future of the US position in space exploration and their belief in extraterrestrial cover-ups (!). And last Wednesday, during a public lecture in San Francisco, legendary astronaut Rusty Schweickart voiced his opinion about NASA's decision to use nuclear technology when faced with an asteroid threat.
Schweickart has expressed concern with the possibility of using nuclear weapons to destroy, or deflect Earth-bound asteroids, pointing out there are many other less harmful ways of dealing with the asteroid threat. At the moment he points out that we are completely unprepared to deal with asteroids, but by 2015, we should have developed a gentler means of deflection. Simply blowing asteroids up have many knock-on implications. First and foremost, Schweickart believes that NASA may be open to manipulation to put forward the proliferation of space-based nuclear weapons under the guise of international "safety." Another problem I can see is blowing up a large piece of rock only to create many smaller (but just as deadly) pieces of rock, doesn't really extinguish the destructive power of an asteroid on collision course, in fact, it might increase it.
Schweickart's organization, the B612 Foundation examines other, more subtle ways of deflecting dangerous asteroids are examined (nuclear warheads not included). Decisions such as when to take action, how to better track asteroids and how to deflect them should be an international effort and not one nation's decision to detonate a nuclear bomb in space.
Source: Wired
July 28th, 2008 at 12:26 pm
Didn't the American Indians have a big laser that could deflect asteroids? Oh. Wait. That was a Star Trek episode…never mind.
Oh and…
Geokstr: Good one!
July 28th, 2008 at 12:44 pm
Just imagine the average asteroid rolling and spinning in space before trying to land the hope of our species on it.
July 28th, 2008 at 4:05 pm
Dave - gravity tractors don't rely on landing on anything. A space probe simply circles the asteroid continuously, the motion slowly nudging it into a new course over many years.
As for this:
"BUT, since I don't know that we actually have any alternatives ready, I'd keep a bunch of nukes ready just in case. Like war or anything else, the nukes are the last chance card. You play it when there is not other choice."
Umm, alternatives? We don't have asteroid-killing nukes ready yet either. It's ALL theoretical at this point, because we've never moved an asteroid. So the nuclear option is just as experimental as the gravity nudge.
July 29th, 2008 at 6:23 am
any non nuclear method of asteroid deflection is either impractical from the engineering point of view, or simply impossible. This is because of newton's first, and second laws. Far left wing political ideaology may not be substituted for sound
science and sound engineering.
tim mayes
July 29th, 2008 at 6:24 am
asreoids are too massive to be moved by anything except nuclear explosions.
it is simply a matter of newtons second law.
tim
July 29th, 2008 at 10:14 am
Asteroids can be moved by mind control if everyone on Earth concentrates on it.
We could also move the Earth out of its way !
July 29th, 2008 at 11:30 am
When it comes to survival no options should be left off the table. You have to know what is coming at you though..
Low density carbon style asteroid? 70% or so of the asteroids out there… What would a nuclear blast do to it? Fuse it into a solid lump or somehow impart enough energy to overcome the gravity that formed it? Gravity tractor sounds more feasable to me
Medium density silica/iron style asteroid? 10% or so population wise. 50/50shot grav tractor vs hydrogen device nuclear weapon?
2 mile wide chunk of nearly pure iron/nickel? 5ish % population, would probably be the best candidate for deflection goal nuclear detonation
Ice/Comet who knows what effect a nuke would have…
Ethan mentioned a no-fallout fusion device but the problem there is getting one of those monsters out of earth orbit. Any other would be a plutonium - deturium / tritium weapon.
As far as space detonations go, both US and Soviets did experiments as far out as 300 or so miles, most of the american tests resulted in pretty lights in the sky and knocking out the power grid of Hawaii
July 29th, 2008 at 1:34 pm
"Far left wing political ideaology may not be substituted for sound science and sound engineering."
And explosions! Don't forget the explosions.
I like explosions.
July 29th, 2008 at 6:01 pm
Ned,
I double checked. m should indeed be the mass of the asteroid, as I originally contended, not the mass of the bomb (the E term comes from the energy emitted by the bomb). Sending a nuclear device this powerful on an accurately aimed rocket could reach an asteroid and detonate, changing course, in a matter of months.
Other solutions, like the ion drive + painting one side (assuming stabilization against the rotation which would result) would take decades for a comparable effect. I'm not saying that your solution isn't safer or just as effective given sufficient lead time, I'm saying that it's a long way down the pipeline.
Ethan
July 30th, 2008 at 12:20 pm
This seems to be a pretty straightforward engineering issue; just use the tools that are appropriate for the job. If you have plenty of time, the non-nuclear options seem appropriate.
If time is short, use nukes. If the asteroid breaks up into chunks, use more nukes. Eventually you'll end up with a really epic meteor shower and a little radioactivity. Better than a giant smoking hole in the ground.
One question: If we see a comet coming at us from the great void, as in Lucifer's Hammer, will we have time to deflect it with nukes?
August 1st, 2008 at 7:27 am
Well I guess no one understands how one uses a nuclear bomb to deflect a threat:
You dont blow it up. People who think you do blow it up got that information from others who are wrong, or from a film.
It is called mass ejection redirection. You detonate close to the surface so that you blow off just enough material to move the impactor slightly. The key here is you have enough warning time.
It would take a huge amount of power to destroy a serious impactor, or deflect it once close. At that point, you might as well focus on digging tunnels.
January 6th, 2009 at 8:08 pm
Tim your wrong, there are hundreds of other ways to move an astroid especially with lots of time. You can't just say "newton's second law" and hope u make sense. However i do agree with the use of nukes