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Chinese Researchers Propose Asteroid Deflection Mission

Soulskill posted more than 2 years ago | from the bruce-willis-need-not-apply dept.

Space 198

wisebabo writes "Researchers in China have proposed sending a solar sail-driven probe to hit the asteroid Apophis to make sure it has no chance of going through a 'keyhole' near earth in 2029. If it goes through the keyhole, then it will hit the earth seven years later. The reason why they need to use a solar sail is because they want the very small probe (~10kg) to hit the asteroid in the opposite direction, a retrograde orbit which would otherwise require an insane amount of fuel (after being put on an escape trajectory, it would need to first cancel out the earth's orbital momentum and then basically speed up to a likewise high velocity in the opposite direction). They are doing this to hit the asteroid at a very high impact speed. While Apophis may not literally be capable of wiping us out (it 'only' weighs 46 million kilograms), it might be able to wreck our civilization." Read on for the rest of wisebabo's thoughts.wisebabo continues, "Rather than putting the fate of our species into the hands of an untried technology (no solar sail has yet imparted substantial delta-V to its spacecraft) may I suggest an alternative? By using Jupiter as a gravity assist, we could send a much heavier probe to hit it at comparable speeds. For example, the Juno spacecraft, recently launched to the gas giant weighs almost 8000kgs. Jupiter could sling a spacecraft around so as to completely cancel its orbital momentum (with no fuel expenditure!). Then it will fall directly towards the sun and, if guided correctly, could hit Apophis broadside. Considering it will be falling from a height of several hundred million miles, it would pack quite a wallop. Admittedly, the impact will be on the side rather than head-on, but that should be okay since all we have to do is assure that Apophis doesn't pass through the keyhole, which is only 600m wide. Don't get me wrong, I hope solar sails become widely used for the (slow, cheap) transport of cargoes in the solar system. It's just that I wouldn't base the defense of earth on them."

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198 comments

Mass != weight (2, Insightful)

ABoerma (941672) | more than 2 years ago | (#37142558)

> (it 'only' weighs 46 million kilograms)

No it doesnâ(TM)t. Kilograms are a unit of mass, not of weight.

"falling" and "height" lol (3, Funny)

Anonymous Coward | more than 2 years ago | (#37142604)

> (it 'only' weighs 46 million kilograms)

No it doesn't. Kilograms are a unit of mass, not of weight.

Yes, this also made me very amused:

Considering it will be falling from a height of several hundred million miles ...

Re:"falling" and "height" lol (3, Informative)

smelch (1988698) | more than 2 years ago | (#37142672)

Does falling only apply to movement toward the Earth now? Can you not fall on the moon? Can the earth not fall toward the sun? Can a probe not fall toward the sun and hit an asteroid?

Can you not say that however high something is is its distance along the normal of the object you are measuring relative to?

It may have amused you, but I think it's correct usage for both words.

Re:"falling" and "height" lol (0)

Anonymous Coward | more than 2 years ago | (#37142836)

So I think "falling toward the sun at a distance of several hundreds of millions of miles" would probably be the preferred usage ... it's also "falling" away from Jupiter, yeah? The lack of a frame of reference or clear indication of acceleration over the span of "several hundreds of millions of miles" make the sentence sound like he's just trying to sell his idea.

I merely found it funny that a craft that far out is given a height, not a distance, and is "falling" instead of being subjected to gravitational pulls.

Re:"falling" and "height" lol (1)

maxwell demon (590494) | more than 2 years ago | (#37142862)

Of course, as long as there's no propulsion, everything in space is in free fall (at least in good approximation).

Re:"falling" and "height" lol (1)

txghia58 (951109) | more than 2 years ago | (#37142860)

Moving in the direction of gravity without additional propulsion.

Re:"falling" and "height" lol (1)

arth1 (260657) | more than 2 years ago | (#37142938)

Moving in the direction of gravity without additional propulsion.

That presumes you're only looking at the gravity vector, and not the speed vector it already has. That's as misleading as saying that a probe on its way to Pluto is falling towards earth. Sure it is, but that it's moving away from earth much faster.

Re:Mass != weight (2)

Trepidity (597) | more than 2 years ago | (#37142670)

Sure, but in informal writing by earthlings, kg as a unit of weight pretty clearly is taken to mean "the weight that a 1 kg object would have at sea-level earth gravity".

Re:Mass != weight (1)

maxwell demon (590494) | more than 2 years ago | (#37142714)

However I'm pretty sure that the number given is its mass, not the weight it has in the gravitational field of the sun.

"Weighs" is polymorphic (2)

tepples (727027) | more than 2 years ago | (#37142908)

It appears we have an open definition debate [c2.com]. Let me define it how I see it: When used with a force unit, "weighs" means "has a weight of". When used with a mass unit, it means "has a mass of" despite its etymological link to "weight".

Re:Mass != weight (2)

hcs_$reboot (1536101) | more than 2 years ago | (#37142914)

Sure, but in informal writing by earthlings, kg as a unit of weight pretty clearly is taken to mean "the weight that a 1 kg object would have at sea-level earth gravity"

Maybe they calculated the actual weight the object will have in 2036, when it'll be at sea level..

Re:Mass != weight (1)

Zalbik (308903) | more than 2 years ago | (#37143234)

Maybe they calculated the actual weight the object will have in 2036, when it'll be at sea level.

What? And you're saying this number is coincidentally exactly the same as it's mass?!?

I think I'm gonna go hide under a rock in 2036.

Re:Mass != weight (1)

geekoid (135745) | more than 2 years ago | (#37143372)

If you step on a scale at sea level, your weight will be 80Kg*. If you to then go into space, your mass would be... 80Kg.

*for this example, natch.

Apophis (4, Funny)

multipartmixed (163409) | more than 2 years ago | (#37142562)

While Apophis may not literally be capable of wiping us out (it 'only' weighs 46 million kilograms), it might be able to wreck our civilization."

Don't worry. Teal'c will take care of Apophis.

Pretzels (5, Insightful)

Anonymous Coward | more than 2 years ago | (#37142564)

Well I hear lots of organizations and governments have made plans to deflect an asteroid with a missile should one threaten to hit Earth. I think it wouldn't be a bad think to practice a little on asteroids that are passing close but not threatening us. I think we'd want to be ready for when a real danger shows up.

Re:Pretzels (1)

gbjbaanb (229885) | more than 2 years ago | (#37142738)

we could practice on it while its way out there. If we miss, we'd have many chances to try again.

But of course, we'll just ignore it due to budgetary concerns until its a real danger and then it'll be too late to do anything other than send Bruce Willis - and he'll be far too old by then!

Re:Pretzels (0)

Anonymous Coward | more than 2 years ago | (#37142856)

That's OK... we still have Chuck. That is, if he hasn't transcended mortality by then.

Do both (1)

JanneM (7445) | more than 2 years ago | (#37142568)

How out doing both? Even if one fails the other would succeed, and you'd test both technologies in a real-world setting. We're talking fairly cheap missions, relatively speaking, and they could almost be worth it just for the incidental research data if you let some of their mass be instruments and communications equipment.

Pointless (2, Informative)

agentgonzo (1026204) | more than 2 years ago | (#37142588)

It's basically been confirmed that it's not going to hit the Earth: http://en.wikipedia.org/wiki/99942_Apophis#History_of_impact_estimates [wikipedia.org], http://en.wikipedia.org/wiki/File:Apophis_pass_zoom.svg [wikipedia.org], but then this is China we're talking about so they probably don't believe the rest of the world's measurements.

and china state tv will just show clips from movie (1)

Joe_Dragon (2206452) | more than 2 years ago | (#37142642)

and china state tv will just show clips from movies or tv shows to show this off.

Re:and china state tv will just show clips from mo (0)

Anonymous Coward | more than 2 years ago | (#37142854)

Top Gun never gets old.

Re:Pointless (-1)

Anonymous Coward | more than 2 years ago | (#37142778)

Yes but it lets the religion known as Space Nuttery celebrate another fictitious "threat" to the ENTIRE SPECIES!!!! (How noble! How grandiose! How selfless!) and the massive technological powers that the human race has! (We're sending, if ever, a super thin paper towel at a rock. The great Galactic Powers tremble at our might! The juvenile power fantasies of the Space Nutters must be appeased!)

Re:Pointless (0)

Anonymous Coward | more than 2 years ago | (#37142874)

waaaah! people should only care about the same branch of science that I care about! whine bitch moan snark complain whiiiiiiine!

Re:Pointless (1)

Nadaka (224565) | more than 2 years ago | (#37143462)

But paper covers rock. That is a much better proposition than sending a pair of scissors.

Re:Pointless (2)

omnichad (1198475) | more than 2 years ago | (#37143262)

It's just a cover. They actually plan to redirect it TOWARD an earth-impact trajectory, unless we pay a hefty ransom. Say, one MILLION dollars?

Divert an asteroid you say? (0)

Anonymous Coward | more than 2 years ago | (#37142626)

What're Bruce Willis and Ben Affleck up to?

Re:Divert an asteroid you say? (0)

Anonymous Coward | more than 2 years ago | (#37142922)

Pretty sure they spend most of their time these days traveling the world letting jackasses like you know that the rest of the world is tired of your crappy, ten year old jokes.

Re:Divert an asteroid you say? (0)

Anonymous Coward | more than 2 years ago | (#37142944)

What're Bruce Willis and Ben Affleck up to?

and this time lets not include Steve Buscemi.

Re:Divert an asteroid you say? (0)

Anonymous Coward | more than 2 years ago | (#37143218)

You mean Jet Li, because this one is going to be the bad ass Chinese guy.

Re:Divert an asteroid you say? (1)

bhcompy (1877290) | more than 2 years ago | (#37143390)

Yea, but he got beat up by Mel Gibson. I think they should send the bad ass Aussies

mass wrong (1)

mapkinase (958129) | more than 2 years ago | (#37142630)

http://en.wikipedia.org/wiki/99942_Apophis [wikipedia.org]

        2.7×10^10 kg

How difficult is it to copy paste?

Re:mass wrong (0)

Anonymous Coward | more than 2 years ago | (#37143192)

it 'only' weighs 46 million kilograms

2.7Ã--10^10 kg mass

Clearly, these Chinese are already inspace occupying a low gravity body!! Since where they are, their gravity is 4.6e7 / 2.7e10 = 0.13% of Earth's gravity, meaning they are probably occupying their secret lair on Juno!

http://en.wikipedia.org/wiki/3_Juno [wikipedia.org]

It is clear that US is vastly behind in secret lairs on asteroids, hence NASA must get immediate funding to match and exceed Chinese lair building program!! How do we know these Chinese do not want to crash Apophis into the Great USA??

2029 headline... (2, Funny)

Anonymous Coward | more than 2 years ago | (#37142636)

"Apophis pushed through 'keyhole' in space by solar sail. Seven year countdown begins."

Re:2029 headline... (1)

Miamicanes (730264) | more than 2 years ago | (#37142936)

Frighteningly enough, I can see this happening. It would almost be better to plot the sail's trajectory to screw with its trajectory if it passes THROUGH the keyhole, and glide by harmlessly if Apophis MISSES the keyhole. By all means get the hardware into position to avert disaster... but if it looks like disaster isn't likely to happen, for the love of ${deity} don't go screwing with it and risk making things worse just for the sake of Doing Something.

It's kind of like theoretical weather-control experiments. If we someday know Tropical Storm Tyreesha is predicted to hit Miami on September 18th and disrupt the season finale of a popular mass-public reality TV show, do we REALLY want to risk kicking it back into the Straits of Florida and nudging it south so it passes harmlessly over the southern Everglades... then unexpectedly deviates from the models, grows into a monster category 5 hurricane over the Gulf, and destroys Houston the way Andrew destroyed Miami, instead of dumping a foot of rain on South Florida, fizzling out, sputtering back to life, and drifting north until it trips over southern Alabama as a minor category 1 hurricane?

Thought experiment: someday, a small asteroid is discovered that, if we do nothing, will strike a relatively desolate part of the earth and do about as much real damage as Tunguska. We have the ability to nudge it a bit. There's a 60% chance that we can make it totally miss the earth, a 20% chance China can make it mostly burn up and destroy a small frontier town in western China that can be easily evacuated, and a 20% chance its remains will sail over the Himalayas and crash within 50 miles of New Delhi. There's also a .5% chance we're totally wrong about its path, and if we are, it could crash into the South China Sea and wipe Hong Kong and the vicinity off the map. Do you let it (hopefully) crash harmlessly into the Gobi Desert and risk a catastrophe that's unlikely to happen, or do you take a much, much higher risk of causing lots of expensive damage (and probably deaths) by trying to screw with it in the hope that whatever you try won't end up making things worse?

Re:2029 headline... (1)

arth1 (260657) | more than 2 years ago | (#37143064)

With risk calculations, you have to multiply the risk percentage with the damage factor.
A 1% risk of 1 billion people dying is a much greater hazard than a 50% risk of 10 million people dying. If you had the chance to turn the former risk into the latter, you'd be a fool or a gambler (but, I repeat myself) not to take it.

What could possibly go wrong? (0)

Anonymous Coward | more than 2 years ago | (#37142644)

There's a nearby asteroid, close to hitting us but almost guaranteed not to. If they go out and meddle with its direction, what could possibly go wrong?

Re:What could possibly go wrong? (1)

gumbi west (610122) | more than 2 years ago | (#37143354)

I think that if you broke it up with wisebabo's method, you would be pretty much guaranteed to cause some of it to impact. You might get lucky and it is a bunch of stuff that well make pretty streaks in the sky... or you could obliterate a continent.

solving a non-problem is always problematic, in this case, it could be devastating.

Might make it worse? (1)

hawguy (1600213) | more than 2 years ago | (#37142660)

Since we still don't even know that it will hit that keyhole (the last stat I saw was 1:250,000 chance), what are the chances that instead of a direct hit, we'll just make a glancing blow that ultimately nudges it through the keyhole?

This mission seems to make more sense if there's a 100% chance it will hit the keyhole, because then there's no way to make it worse, but I'd like to see some statistics on the chances of making the situation worse (or on completely missing it and doing nothing at all)

At the very least, we should plan on *two* missions... one farther away, and then if it turns out we haven't pushed it out of the way, send a modified spaceshuttle full of Texas Oil workers to drill a hole and plant a nuclear bomb in its core. Then they could make a movie about it.

Re:Might make it worse? (1)

sqlrob (173498) | more than 2 years ago | (#37142972)

They've already done the mission with another asteroid. Haven't you seen the broadcasts on the Chinese news?

Declaration of War? (0)

Anonymous Coward | more than 2 years ago | (#37142662)

So, assume that with this new trajectory it will unintentionally hit another inhabited planet in some distant future. They may discover pieces of the probe before impact and assume that it's being sent to their planet as an intentional act of war. We will then be doomed...

Re:Declaration of War? (0)

Anonymous Coward | more than 2 years ago | (#37142756)

Their planet just got hit by an asteroid, they're in no shape to start a war. Besides that, if they couldn't stop the asteroid they're in no position to conduct interstellar war anyway. Besides that, in the millions of years that it would take for the asteroid to reach another star and hit a planet we will either be long dead (most likely) or powerful enough to win the war.

Problem solved.

Re:Declaration of War? (0)

Anonymous Coward | more than 2 years ago | (#37142858)

congratulations, that's the most retarded post yet today.

Slashdot editors hate my long-windedness (0)

wisebabo (638845) | more than 2 years ago | (#37142678)

In my submission I actually had some more speculation:

"Then again, if you were able to very accurately control the asteroid impactor, not only could you control IF the asteroid was going to go through the keyhole but WHERE it was going to go through. Then you could determine where, on earth, the asteroid was going to eventually going to hit."

Say on an unfriendly nation (that was preferably on another continent).

But then again they didn't like my submission on how you could convert the promising pan-viral "cure" (MIT Tech review) that doesn't kill the virus directly but rather the cells it infects into a biological weapon of universal power.

By the way, the Jupiter slingshot idea has been proposed to send a probe on a (one-way) trip to the sun. A variant of this idea was used to send the Ulysses spacecraft into a sun polar orbit. It allowed them to use a Delta launch vehicle instead of a Saturn V.

Re:Slashdot editors hate my long-windedness (1)

geekoid (135745) | more than 2 years ago | (#37143438)

Yes, there would be no retaliation during the 7 years it takes for it to return and hot the target. Or any attempt to change it by other nations.

Chinese (3, Interesting)

immakiku (777365) | more than 2 years ago | (#37142684)

I think it's interesting that in most doomsday asteroid scenarios, the US is the one to launch a mission to save the earth. Granted, part of that is because Hollywood wrote those scenarios, but generally the rest of the world doesn't think twice when watching those movies because US is the de facto leader in most things. I think this is a telling inflection point in the history of nations.

Re:Chinese (4, Insightful)

Nidi62 (1525137) | more than 2 years ago | (#37143010)

It's probably because, at least until recently, the US would be the country that would be best able to absorb the brunt of the costs associated with a mission such as this. Also, US-affiliated technology would have to play some sort of role regardless. But really, should a scenario like this actually occur, I would expect that most countries would contribute in some way.

Re:Chinese (0)

RivenAleem (1590553) | more than 2 years ago | (#37143194)

What money do you think they would be absorbing this with? The Massive deficit they have had since before Gulf War, or the money they borrowed from, guess who, China?

Re:Chinese (1)

Nidi62 (1525137) | more than 2 years ago | (#37143220)

What money do you think they would be absorbing this with? The Massive deficit they have had since before Gulf War, or the money they borrowed from, guess who, China?

Did you notice the "at least until recently" clause there in my first sentence? It's only 3 words in, so I would hope so.

Re:Chinese (1)

maxwell demon (590494) | more than 2 years ago | (#37143316)

Did you notice the "at least until recently" clause there in my first sentence? It's only 3 words in, so I would hope so.

Hmmm ...
"at" - 1
"least" - 2
"until" - 3
"recently" - 4

Re:Chinese (1)

RivenAleem (1590553) | more than 2 years ago | (#37143502)

Except it's not recent. The raising of the debt ceiling is recent. Hollywood has been making many movies where they are the wealthy powerhouse since before gulf war, despite being massively in debt and borrowing off China and other countries.

Re:Chinese (1)

geekoid (135745) | more than 2 years ago | (#37143524)

See? people like yuou piss me off. You have no clue and ecnoomis work, you go on about the deficit, something you clearly know nothing abuot exept what you ahve been spopon fed by the media.

This is what wuod happen:
COngress would give NASA an effective blank check.
NASA would get a plan, hire a lot of contractors, and build the thing. Many people would get a lot of money, and in fact jobless would drop.
The people getting paid get taxed.

Every company and pretty much every American runs a deficit. How many people get a loan to buy a house? deficit! or a car? Deficit! A company needs to get a loan to buy equipment? deficit!

I am not saying it shouldn't be watched and dealt with intelligently, just that it is no inherently 'bad'.

As a clue to how complex this topic is, here is a factoid:
Every penny of the deficit goes right into the private sector.

THAT is why austerity has never gotten anyone out of a recession.

Yeah but the Chinese don't have experience... (2)

wisebabo (638845) | more than 2 years ago | (#37143144)

... in gravity assists (which as I pointed out in my submission) could make the mission much cheaper and less risky.

Since they don't have any experience with gravity assists and (no-one) has any real experience with solar sails, I figure they just picked the one that sounded more sexy. If they actually had a long track record of deep space missions (they've only gotten to the moon whereas the U.S. is on its way to PLUTO), they wouldn't go this route. So I think the inflection point is still a ways off.

Re:Chinese (0)

Anonymous Coward | more than 2 years ago | (#37143196)

Well since at least 'Independence Day" we're wondering, here, in Europe, why the heck in more or less all End of the World movies are the US the only able to save the world and why do we always need to be told how to kill the bad guy ...

Re:Chinese (1)

JanneM (7445) | more than 2 years ago | (#37143232)

"[â¦.]but generally the rest of the world doesn't think twice when watching those movies[...]"

Why do you assume that?

I mean, unless you speak the language and participate in the local conversation you're not likely to pick up anything about how people react and what they think, right?

Seven years later? 2038! (1)

Slartibartfast (3395) | more than 2 years ago | (#37142688)

See? The end of the epoch *is* the end of life! Screw the Aztecs...

Re:Seven years later? 2038! (0)

Anonymous Coward | more than 2 years ago | (#37142828)

I've been telling people all along that Dennis Ritchie was way smarter than a bunch of ancient Mayans.

Re:Seven years later? 2038! (2)

Elbart (1233584) | more than 2 years ago | (#37142852)

You might want to check the numbers again. 2029 + 7 = ?

Re:Seven years later? 2038! (0)

Anonymous Coward | more than 2 years ago | (#37143320)

Mesoamericans used very large sevens.

Re:Seven years later? 2038! (0)

Anonymous Coward | more than 2 years ago | (#37143460)

You might want to check the numbers again. 2029 + 7 = ?

Well, civilization won't die overnight. I'd give it two years to fully collapse. So...

2029 + 7 + 2 = 2038.

And that's how numerology wins, people. Random fact-free assumptions. :)

Re:Seven years later? 2038! (2)

omnichad (1198475) | more than 2 years ago | (#37143470)

It's one year early. Our mission to the moon started a 2^32 second timer, counting down to our demise - we were deemed a threat once we began manned space exploration to the moon.

I wouldn't hit it (2)

Ken_g6 (775014) | more than 2 years ago | (#37142694)

I worry that an impact, rather than moving the entire asteroid, could shatter it and make it much more likely that one small (but still potentially dangerous) part would go through the keyhole.

Re:I wouldn't hit it (0)

Anonymous Coward | more than 2 years ago | (#37142844)

It's an estimated 300m in diameter. The chances any human-built impactor short of an atomic weapon could fragment the thing are pretty slim.

Re:I wouldn't hit it (2)

gumbi west (610122) | more than 2 years ago | (#37143394)

Slimmer than or less slim than its chance of passing through the keyhole?

The thing is that if we even knew where it was precisely enough to target it, we wouldn't have to guess about if it will pass through the keyhole.

Re:I wouldn't hit it (1)

munozdj (1787326) | more than 2 years ago | (#37143222)

My worries are that moving the asteroid could somehow disrupt the balance of the solar system and have gravitational repercussions with other objects, kind of a butterfly effect... Yes, it's small, but if it disbalances the orbit of another object, and those do the same thing to others... the millon-years-old balance that we have in the solar system could be wrecked. Just a very wild thought. Any astrophysicist that could help me with this? Is it really possible, or is the lack of coffee messing with my mind?

Re:I wouldn't hit it (0)

Anonymous Coward | more than 2 years ago | (#37143346)

Im more worried about the chain reaction it might cause. What happens when we deflect it into a different path which crashes it into another asteroid changing its path... rinse repeat.

Re:I wouldn't hit it (0)

Anonymous Coward | more than 2 years ago | (#37143526)

10 kg vs. 46,000,000 kg? Really?

Re:I wouldn't hit it (0)

Anonymous Coward | more than 2 years ago | (#37143550)

The asteroid is 4.6 million times more massive than the probe. What kind of insane (relativistic?) velocity would be required to shatter an asteroid 6 orders of magnitude bigger than the projectile?

Not sure it matters... (0)

Anonymous Coward | more than 2 years ago | (#37142716)

If it hits in '36, I'll be 86. I likely won't care one way or another. Besides, civilization as we know it will end at 21:14:07 UTC on Monday, January 18, 2038, so even if the earth doesn't get smacked, we will be in pretty serious trouble.

Re:Not sure it matters... (1)

stderr_dk (902007) | more than 2 years ago | (#37142902)

Besides, civilization as we know it will end at 21:14:07 UTC on Monday, January 18, 2038

Really? That's 6 hours earlier than most estimates...


$ date -u -d @2147483647
Tue Jan 19 03:14:07 UTC 2038

Re:Not sure it matters... (1)

maxwell demon (590494) | more than 2 years ago | (#37143114)

It of course depends on the time zone you are in. See the UTC in the output? If you are at UTC-6, it will be 6 hours "earlier". UTC-6 happens to be in the U.S. (CST).

Re:Not sure it matters... (1)

maxwell demon (590494) | more than 2 years ago | (#37142924)

If it hits in '36, I'll be 86. I likely won't care one way or another. Besides, civilization as we know it will end at 21:14:07 UTC on Monday, January 18, 2038, so even if the earth doesn't get smacked, we will be in pretty serious trouble.

Maybe someone should start porting civilization to 64 bits. :-)

Aliens Will Come To Save Mankind OR (1)

lecheiron (2441744) | more than 2 years ago | (#37142762)

they will come to destroy us for putting Apophis (jigily-hi in their native language) in collision course with their civilization.

Uhh, I think I read about this before. (1)

Anonymous Coward | more than 2 years ago | (#37142784)

"Meanwhile, the Chinese, in order to retaliate for biological attacks by the US, detonate a huge explosion next to an asteroid (2002OA), with the aim of deflecting it into Earth orbit and threatening the world with targeted precision strikes in the future. Unfortunately, their calculations are wrong as they didn't take into account the size of the asteroid could cause a Cretaceous-Tertiary extinction event. The asteroid strikes Earth, critically damaging the planetary ecosystem. The Titan team members are presumably the last humans left alive."

http://en.wikipedia.org/wiki/Titan_(Stephen_Baxter_novel)

Why not remain blissfully ignorant (2)

Iniamyen (2440798) | more than 2 years ago | (#37142804)

So they figured out that generalized multi-body problem, then, I guess? There are so many variables and errors in our best calculations that a mission like that is probably just as likely to doom us as it is to save us. We'd probably end up pushing it right into Los Angeles. (Wait, that could be a good thing...)

Who says they get the rotation right (0)

Anonymous Coward | more than 2 years ago | (#37142808)

What if instead of hitting the asteroid away from the keyhole, they really want to hit it through the keyhole?

Idiotic and Dangerous (1)

Anonymous Coward | more than 2 years ago | (#37142824)

First, Apophis will not hit Earth, neither in 2029 nor in 2036.

Second, such a scheme would be incredibly dangerous. When you look at how close Apophis will pass (Apophis 2029 Pass [wikimedia.org]), a mission to deflect it might just give it the little nudge it needs to hit Earth if something goes wrong. If you want to test deflecting strategies, please do it on an asteroid that is not going anywhere near Earth.

Third, the whole impactor idea is bad. There is no way to predict how an asteroid will react to an impact. It might make things worse, or more likely will have no effect. A gravity tractor is a much more subtle and effective method. It works because we can detect asteroids that pose a threat years in advance, and it allows precise control of the trajectory.

Experienced Asteroid Wranglers Wanted (0)

Anonymous Coward | more than 2 years ago | (#37143100)

Anything that adds to our knowledge of working with asteroids is ok by me.

Sounds like something out of Civilization (1)

djdanlib (732853) | more than 2 years ago | (#37143344)

Right before they finish building this project...

"Project cancelled."
"Incan civilization completes wonder: Asteroid Defense Satellite"

Or maybe it would be more appropriate for SMAC instead of Civ...

Mass contradiction (1)

NumLuck (1632865) | more than 2 years ago | (#37143522)

Puting aside the debate on mass and weight, there seems to be some contradiction on the mass of Apophis.

In the post, it is 46 million kg (pretty lightweight), in the first link of the post it is 46 million tonnes and on wikipedia (http://en.wikipedia.org/wiki/99942_Apophis) it is 27 million tonnes...

Use a solar sail directly (1)

Toonol (1057698) | more than 2 years ago | (#37143542)

How about not concerning yourself with impacting it at high speed, but simply landing on it and then activating the solar sale? Twenty-nine years of drag from that would certainly deflect it from its orbit.

If the solar sale provided enough delta-v to accelerate a ram, in less than a year, to a speed high enough to deflect the rock, it would necessarily be powerful enough to directly maneuver the rock.

yet another conversion error (3, Informative)

sidyan (110067) | more than 2 years ago | (#37143546)

Juno's [wikipedia.org] mass is listed as 3625kg, or almost 8000 pounds, not almost 8 metric tons.

As for the energy obtained from "falling several hundred million miles": that would be exactly the same energy it took to get that far "up" in the first place (not saying that there's no energy to steal from Jupiter, but it's a pretty hair-brained plan, imho, not in the least because such a trajectory would probably take the better part of a decade to complete).

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