Asteroid 4179 Toutatis Will Miss Earth, This Time 301
EtherAlchemist writes "National Geographic News reports in this story that a giant, peanut shaped asteroid known as 4179 Toutatis will pass within 1 million miles of Earth on Weds, the 29th. When it does, it will be the closest any known object of this size (3 miles) has passed near Earth in this century. No worry about impact yet, it should pose no threat until at least 2562. An interesting note: the asteroid believed to have caused Earth's biggest mass extinction is thought to have been between 3.7 and 7.5 miles as reported here in 2001." 2004 FU162 came closer, but is a much smaller object.
Painting Your Way to Safety (Score:1, Interesting)
1. Just load an ICBM [spacedaily.com] with gallons of white paint and smash the missile onto the asteroid. (This method works for small asteroids.) The light from the sun will push the newly painted asteroid onto a different flight path.
2. Load an ICBM with a hydrogen bomb. Smash the missile into the asteroid.
All is well.
what if...? (Score:5, Interesting)
it's a similar problem to global warming, except there are no asteroid-impact-dependent business models funding research and laws like with oil.
Chances of getting hit soon are ridiculous (Score:3, Interesting)
Yes, it would be bad.
Yes, it's going to happen if we don't stop it.
No, it's not going to happen in your lifetime.
No, I'm not giving you lots of money to try to stop one with primitive turn-of-the-millennium technology. When legitimate investments in space travel bring the cost of launch down and our robotics/sensors are better and our deep space propulsion systems are better, THEN I'll vote for spending money on a decent system.
Or I would, if I wasn't going to die in the global bio-weapons apocalypse of 2027.
How long before we can reach it with rockets (Score:2, Interesting)
Re:Painting Your Way to Safety - half right (Score:2, Interesting)
Re:what if...? (Score:2, Interesting)
Meanwhile, global warming remains a nearly unknown "problem" ignored by all but a few geeks on specialist websites, never mentioned in the news media or turned into a political issue. The oil barons have buried their dirty secret where no one (but rokzy) knows about it.
Re:Painting Your Way to Safety - half right (Score:2, Interesting)
Re:Painting Your Way to Safety - half right (Score:3, Interesting)
And dump the heat into the atmosphere. Congratulations you have just managed to convert the energy from a kinetic impact into a heat event probably affecting a much wider range than before.
The choices
A) smashed: solid ground absorbes energy
B) broiled: atmosphere absorbs energy
Re:Painting Your Way to Safety (Score:1, Interesting)
A broken up asteroid is going to have more surface area than a whole asteroid. The broken up asteroid is going to lose more mass and velocity in the atmosphere than the whole asteroid. The impact will also be more wildly distributed, which may or may not be a good thing depending on the circumstances.
Moon? (Score:5, Interesting)
Too many questions -- no idea of the impact (pun intended.)
Re:Not especially close (Score:2, Interesting)
Depending on the angle of impact effects would range from 'basically nothing' to 'global winter'.
* Near side hit: Asteroid passes by the Earth *then* smacks into the moon
* Far side hit: Moon plays left tackle; catches asteroid before it goes by the Earth.
A 'near side' hit would probably throw enough ejecta into Earth orbit to have global concequences, possible ranging all the way up to the same effect as a nuclear winter. A guess would be that we would probably just see some seriously bad winters until the solar wind pushed all the atomized dust out of orbit -- no super-long term effects, but it would still be an Unhappy Event. Certainly a number of people would be killed by incoming ejecta, but no more so than generally die in car wrecks. Actually, more people would probably die in car wrecks because they were looking up at the fireballs streaking across the sky instead of driving.
A far side hit would *probably* just create a big-ass halo around the moon for a while. The key difference is the the ejecta would go up and OUT -- away from Earth orbit.
The impact crater would act kind of like a rocket nozzle, aiming gobs of rock and atmomized moon dust out into space -- or towards whatever is in its way. If it aims towards or obliqe to earth, much of that would go into orbit or enter earths atmosphere. Bad times. But the amount of stuff ejected depends on a whole slew of factors, things like 'did it hit bedrock or a 'valley' full of lunar dust?
While I am a rocket scientist (well, I have a degree anyway), I don't study impacts. These are just educated guesses based on err, my education
Oh, and: No, a three mile asteroid could NOT significantly adjust the moons orbit and NO it would NOT end all tides, nor would it have any chance of seriously damaging the moon. Moon: 1738 km radius. asteroid: ~4.8km radius. We might need to re-calculate the moons orbit at the 5th decimal place after an impact.... Maybe.
What painting does (Score:5, Interesting)
- Both solar and thermal radiation exert pressure.
- The incoming solar radiation pushes away from the Sun, but the thermal re-radiation from the asteroid pushes away from the hottest parts.
- Asteroids rotate, so the thermal-radiation pressure is not directly away from the Sun but away from the "afternoon" part. The lower the albedo (darker) and the greater the thermal conductivity (lag between peak insolation and peak temperature), the greater the difference between the direction to the Sun and the thrust vector.
By painting the asteroid whiter (or, in theory, darker) you change the amount of heat absorbed and thus the ratio between the thrust from the reflected light (tracks exactly with incoming light) and the thrust from the radiated heat. Given enough time this will let you change the orbit of the rock enough to miss (or possibly hit) what you want it to. This works best with smaller bodies and long (very long) lead times.Re:Definitely worth it (Score:3, Interesting)
Re:Painting Your Way to Safety - half right (Score:3, Interesting)
The most likely result of such a fracture would be a small number of rocks with diameters ranging from a few tens of meters to hundreds of thousands of meters, and a small amount of gravel. A lot of that depends on what the composition of the asteroid is. If it's carbonaceous - like comets - there would be smaller fragments - if it's a stony or iron composition, it's unlikely we'd be able to fracture it at all, or if we could, then into very large chunks.
The REAL migraine there is that if the result was a lot of big chunks, their orbits would be altered enough that it's possible that they'd touch down at points distributed along the line of the Earth's rotation, thereby distributing the destruction even more widely. Remember, even a large ~ 3-8km-diameter asteroid's impact zone will be somewhat localized - even if it did alter the global climate, the worst effects would stay within one hemisphere. Not so with a time-distributed impact of many semi-large rocks.
Anything along these lines will have to be contemplated and modelled VERY carefully; the best data we could get would be if we had time to land probes on the asteroid in question and get seismic soundings of it's structure, and even then we'd still be playing with a lot of uncertaintities.
We should be pursuing studies and sending probes like this right now, so that if in the future the necessity emerges we at least have a good amount of data on many different rocks to use in our calculations, rather than some hurried-up last minute/year effort. But hell, this is all gibberish to most of those morons who make policy anyway, so what's the point of arguing it anymore in the public venue? Well, we need funding for those probes and studies... and like many other issues that need attention, this one is being ignored this year in favor of arguing over people's fucking war records from thirty years ago, and this in the country that is the world's most technologically capable society.
Sometimes I wonder if humanity as a whole hasn't already drank the koolaid.
slash rant
Sigh. Goddamn I hate election years.
SB
Re:Moon? Don't worry. (Score:2, Interesting)
Well, the earth's diameter is four times the moon's, so the area it presents is sixteen times the moon's. Therefore the probability of hitting the earth is sixteen times that of hitting the moon, and we really should be at least 16 times as worried about earth impacts as moon impacts.
Further, the orbit of the moon is 60 times the size of the earth, so the area it presents is 3600 times the area the earth presents. If an asteroid comes whizzing through, inside the moon's orbit (an unlikely event in itself), its probability of missing is 3600 times it hitting the earth or the moon.