NASA Downgrades Asteroid-Earth Collision Risk 244
coondoggie writes "NASA scientists have recalculated the path of a large asteroid known as Apophis and now say it has only a very slim chance of banging into Earth.. The Apophis asteroid is approximately the size of two-and-a-half football fields, and updated computational techniques and newly available data indicate the probability of an Earth encounter on April 13, 2036 for Apophis has dropped from one-in-45,000 to about four-in-a million, NASA stated."
four in a million? (Score:5, Insightful)
Isn't four in a million the same as one in 250,000 ?
Re:four in a million? (Score:5, Funny)
Re:four in a million? (Score:4, Informative)
According to NASA, it is 1 in 135,000 and diameter is 0.270 km
http://neo.jpl.nasa.gov/risk/a99942.html [nasa.gov]
The image on TFA gives the impression that it is way larger than 20km and the summary claims that is is 200 yard = 0.182 km. And the text claims that it is four-in-a million aka 1 in 250.000.
Re:four in a million? (Score:4, Insightful)
Yes, but four-in-a-million is only five syllables, and thus much more useful.
Four in a million
NASA says we might survive
with hyperbole
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Except for Rincewind and the Luggage.
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Re:four in a million? (Score:5, Funny)
Yeah, I RTA, saw the image of an asteroid that was apparently about 60km long, with the text "The Apophis asteroid is approximately the size of two-and-a-half football fields" and I suddenly had a whole lot more respect for US football.
(I saw the title of the article after)
Re:four in a million? (Score:4, Funny)
Bill
Re:four in a million? (Score:5, Funny)
Your totally wrong.
His totally wrong what?
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Well yes, but "million" sounds more impressive.
Re:four in a million? (Score:5, Funny)
I am a programmer. I am paid to produce syntax not grammar. Deal with it.
Sorry for the off-topic troll, but I really can't resist your signature. I'll answer your self-satisfied, pedantic quibble with one of my own.
Programmers, unless they are creating new languages, do not produce syntax, they obey syntax [wikipedia.org]. Setting this point aside, maybe you meant, "I am paid to produce things which are syntactically correct, not things which are grammatically correct." Of course, you actually are paid to produce things that are grammatically [wikipedia.org] correct.
Perhaps you meant, "I am paid to write in the highly precise, fascinating languages of computers and not the boring, ambiguous English language that my incompetent high school teachers made me hate." That might be true, but it probably isn't. Most programming jobs require quite a bit of written English, and the more grammatically correct it is, the better. Admittedly, this is usually less important than producing working code.
Another possible reading: "I never quite understood English grammar, even though I felt like I should. I compensate by basing my fragile self image on excessive pride in my other skills and wearing a chip on my shoulder so people will be afraid to call me on it."
They were right... 18% chance (Score:2)
So the change was downgraded to 18% chance that the original value of 0.0022% was right.
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So it's 1-in-250,000 instead of 1-in-200,000 or 1-in-166,666ish?
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In this, statistical case, yes.
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...because of the million times we might have been hit, we only got hit four times i.e. one in 250k. (In other words: "I shouldn't have said statistical. I Should have gone to sleep."
Comparing different ratios... (Score:2, Insightful)
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Yes, but can we get this in a real world equivalent. Something like 1200 words out of a library of congress?
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But none would get funding for 22 in a million. I mean a million is such a big number, it wouldnt happen. ;)
Metric? (Score:5, Funny)
So is that US football fields or are we using the metric system (ie. Soccer fields) ?
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It's about 0.0000001 times the size of Wales.
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It's about 0.0000001 times the size of Wales.
That's no help. Humpback Wales or Dr. Who Wales?
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One very surprised looking sperm whale and a bowl of petunias.
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Re:Metric? (Score:4, Funny)
Re:Metric? (Score:4, Funny)
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What about Canadian Football fields? Does that include end zones?
Does anyone else see the stupidity of trying to compare the size of a three dimensional object to a two dimensional object?
I'm assuming they're talking diameter here, but still... is it perfectly round? Is it average diameter or maximum diameter?
Four in a million, huh? (Score:4, Insightful)
And "two football fields" doesn't tell us much about the thing's actual size. Besides "football" having two different meanings, one of which has multiple field sizes, what kind of volume are we looking at here?
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Apparently those are some pretty big football fields.
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Looks bigger than that in the picture.
Of course, the text also said it was less than two football fields long, not two and a half football fields. Who writes this stuff?
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Who writes this stuff?
And what are they drinking/smoking?
The title and the picture don't match. From Wikipedia:
"Based upon the observed brightness, Apophis' length was estimated at 450 metres (1,500 ft); a more refined estimate based on spectroscopic observations at NASA's Infrared Telescope Facility in Hawaii by Binzel, Rivkin, Bus, and Tokunaga (2005) is 350 metres (1,100 ft)."
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Actually, come to that, it looks like Phobos. Scale is still off, Phobos isn't 60+ km across either, but that big crater is pretty distinctive.
Re:Four in a million, huh? (Score:5, Informative)
Posted too soon, I did. Should have checked the source of the picture first.
What we have accompanying the article on Apophis is a picture of Asteroid 253 Mathilde. Apparently pulled off the NASA website at random by the author's of TFA.
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Agreed. Why can't they use more useful units?
For example, how many "Library of Congresses" is it?
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Yes, I get upset when they compare objects (where the important dimension is mass (weight) and maybe volume,) to something that is clearly a measure of area at best.
Similarly hail should not be sized by coins.
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Obviously they were talking about surface area, and the asteroid is shaped like here (start at timecode 1:14) [youtube.com]
Re:Four in a million, huh? (Score:5, Funny)
How about 1 in 250,000? And "two football fields" doesn't tell us much about the thing's actual size.
You're translating from Jock to Geek. The Jock's understand a million as "a really big number" and 4 as a really small one. 250 is compleltely beyond them, let alone 250 times 1000! Football fields is a much more natural unit to them than a meter. Never mind that they're different sizes - they can all relate to being exhausted running the length of a football field. The concept of a meter just hurts their poor roid ridden brains.
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I know about Gaelic Football, but what is the other one? Surely Aussie rules doesn't count!
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Phe, Phi, Pho, Phum, I smell an article pulled out of his bum.
Uh oh... (Score:3, Insightful)
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lets see... plus 1.... carry the 2.... equals.....uhhhh..... 57....
oh shit... I will only be old.
and we will all miss the slashdot 40th anaversery too!!! fuck!
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make that:
anniversary
awww damn... I won't be able to post correct myself either!!!
this world ending stuff just sucks.
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Edward A. Murphy Jr [wikipedia.org] - smartest man who ever lived.
As much as I hate his fucking law, it always becomes obviously true, time and time again.
Bad Economy (Score:5, Funny)
Even the chance of an apocalypse is being downsized.
Dammit... (Score:5, Funny)
40 rods to a hogshead = 1.8 Library of Congresses? (Score:2)
Can we keep our units/ratios consistent?
When you're regurgitating statistics that are generally considered good news - such as the decreased chance of global catastrophe - doesn't it seem reasonable to make those statistics int
Soothsaying (Score:3, Insightful)
Clearly 4 in a *million* must be a very very small number, not like 1 in 250000 - which has thousands on the right-hand side, so that can't be good.
In an attempt to make a new probability "less scary" the authors (or summary writers) also commit a specific error - there is only ONE asteroid so any probability related to it is ALWAYS 1 in something. It can never be 4 in something because there is only once chance of collision.
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No, no that would be a million universes.
Of which, the asteroid will strike Earth in four of them.
There is a 1 in 250,000 chance, however, that anyone reading this will be in one of the four.
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ah-HA! But it's on an orbit!
BOOYA!
just kidding. Well, it is on an orbit, but I don't think the orbit will allow it to have more than one chance of hitting us within the given time frame.
Symantics at Play (Score:2)
That's good to know (Score:2)
Because Jack O'Neil's getting too old to stop those Goald asteriods.
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Apophis? (Score:3, Funny)
Remember the Mars Orbiter (Score:2, Informative)
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no that was to take out the Goa'uld base there.
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They were just adjusting Mars' orbit for the next shot. Now vee have dem vere vee vant dem!!
On a positive note... (Score:4, Funny)
And yet... (Score:2)
People keep buying lottery tickets.
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Will Bruce Willis still be here to save us? (Score:2, Funny)
Born: March 19, 1955. That will put him at 81 years old... We better freeze him now, so we can thaw him out in case of an impending asteroid strike.
NASA and risk... (Score:4, Interesting)
Taken from: http://en.wikipedia.org/wiki/Rogers_Commission [wikipedia.org]
"Feynman was clearly disturbed by the fact that NASA management not only misunderstood this concept, but in fact inverted it by using a term denoting an extra level of safety to describe a part that was actually defective and unsafe. Feynman continued to investigate the lack of communication between NASA's management and its engineers, and was struck by management's claim that the risk of catastrophic malfunction on the shuttle was 1 in 10^5; i.e., 1 in 100,000. Feynman immediately realized that this claim was risible on its face; as he described, this assessment of risk would entail that NASA could expect to launch a shuttle every day for the next 274 years without an accident."
Well, it has nothing to do with the topic, but I wouldn't trust a statement "four-in-a million" made by NASA... ;-)
There is no guarantee for a secure life on this planet. Asteroid impacts are a part of the nature, so everybody should be aware of those risks...
Re:NASA and risk... (Score:5, Insightful)
This kind of uncertainty is much easier to derive with fewer question marks than deriving the risk of catastrophic failure in a complex machine.
Basically what this implies is that taking new measurements, we have an improved estimate of the position of the asteroid at the current time, and the risk of impact is taken by projecting those into the future using well known and tested dynamic estimation methods. Current uncertainty is easily defined as a 6x6 covariance matrix (for the 6 state variables), and this matrix can be determined using a good least-squares estimation method and published measurement numbers.
In other words I give these numbers a lot more credence than risk numbers on the space shuttle. Theres a lot more science and lot fewer assumptions.
Also I would be careful comparing practices in the huge human-spaceflight program, centered at JSC and KSC with those of smaller planetery exploration programs from places like JPL and Ames. They have amazingly different cultures and practices -- NASA is in no way a monolithic entity.
first four entries on impact table (Score:2, Informative)
There are three objects with higher probability of impact on the list, two of them much larger than Apophis (270 m diameter). Their diameters are 560 m and 780 m.
http://neo.jpl.nasa.gov/risk/ [nasa.gov]
Scroll down to "Objects not recently observed"
No Stargate references? (Score:2)
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Or, we could just mine all the naqadah out of it and use it to power generators. . . something the SGC completely failed to capitalize on. It seems like they are always looking for a source of naqadah, than when Apophis delivers it their doorstep, they just let it fly off into deep space. . .
Two-and-a-half football fields ? (Score:2)
Two-and-a-half football fields? Does this include the stands and the parking lots? They couldn't give it to us in meters?
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Two-and-a-half football fields? Does this include the stands and the parking lots?
No, that'd be two football stadiums. This is just the fields. Plus one bitchin' tailgate party.
They couldn't give it to us in meters?
Big numbers fit bad in caveman brain. Big rock fall from sky, kill many mammoth. As many mammoth as fit on headball field. Lot of mammoth. Headball fun. Kick head of enemy caveman around. Mammoth get in way. New dead mammoth good, old dead mammoth bad. Smell bad. Worse than cave.
Wait for it.... (Score:2)
Wait for it...
Wait for iiiiit...
Waaaaiiit foooorrr iiiiit....
No, missed!
Consistency In Data Barfing (Score:5, Funny)
Apophis had been downgraded to 4 chances in a million from 22 chances in a million. This new figure is clearly wrong, because it has 6 chances to impact between 2036 and 2103 (see http://neo.jpl.nasa.gov/risk/a99942.html [nasa.gov] ). Perhaps this means the actual metric is 6 chances per 1.5 million.
Also of note in the upgraded data is the second of the 2068 near misses, having a 0.00 Earth radius distance. This is likely a statistical artifact caused by the fact that a near miss is a hit (a miss is a miss or it isn't; something that comes close but doesn't hit is a near hit).
Since the distance is zero but the impact probability is 1.1e-07, they have almost certainly determined that it will pass by (and/or impact) almost perfectly edge on. Due to its size being equivalent to 2.5 football fields, and a football field being a 2 dimensional rectangle with no thickness, an edge on impact would have little effect, keeping all 510 megatons of impact energy confined within an area of 270 by 0.000... meters, ie. no area at all. Thus, the impact will have absolutely no effect unless you happen to be standing over that 270 by zero meter line when it comes down on you, or worse, up at you after having passed through the Earth (a zero thickness should be able to pass through the planet like a neutrino).
Hopefully we will also get updated figures on 2007 VK184. It has a 340 in 1 million chance of impact. It gets 4 attempts between 2048 and 2057. Four chances in 9 years gives it 2.25 million years to have its one million attempts, in which time it will only hit Earth 340 times, or once every 2417095.5882352941176470588235294 days. This was calculated with due attention paid to leap years, though it is uncertain at the time of publication whether the frequent legislating of time standards by the US will result in the figure being in standard leap years or daylight savings leap years.
Just to add a minor point of confusion, in case it has been so far missed: the question has been raised regarding the actual size of these objects, as 'football field' is ambiguous, there being two different kinds of 'football' using different size fields. The answer is that it doesn't matter. NASA has already proven themselves to be above and beyond the need for conversion factors, and so they need not differentiate between metric and non-metric football. In their usual excessively polite manner, Canada has repeatedly not pointed out that they too have 'football' similar to the US kind, but with yet another differently sized field. Their reticence is somewhat practical when one considers that fewer people watch Canadian football than watch curling, and nobody outside Canada watches that.
smacks of a certain BBC weather report... (Score:2)
...in which Michael Fish declared that the massive depression booting it across the Atlantic was /not/ a hurricane and was /not/ about to rip the UK a new arse.
He was wrong.
Asteroid no longer a big of an issue (Score:2)
While good news for sure.... science believes this was indirectly caused by universal climate change. Sigh...
If we don't do something about solar helium production we're all doomed!
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Apohpis? Everybody knows it was Anubis who sent the asteroid.
Just cut the red wire (but they're all yellow!)
Yep, plan 3 works every time.
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Maybe 4 in a million makes people feel better. I mean, a million is alot bigger than 45000 isn't it!
Personally I think they just stuffed up converting imperial to metric somewhere.
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Nope. It's Hot Fudge Sunday.
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Million-to-one chances crop up 9 times out of 10.
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I mean, who knows if the path of the asteroid may deviate a little bit due to gravitational pull of different planets/stars etc
If there are any stars out there besides the sun close enough to affect this asteroid... we're pretty much fucked already.
Re:is this too early to predict path ? (Score:4, Interesting)
I mean, who knows if the path of the asteroid may deviate a little bit due to gravitational pull of different planets/stars etc.
Well they're pretty certain that it will deviate due to the variety of forces on it, which is exactly why the result is given as a probability, rather than a "will hit" or "will miss by X miles". It's also why the probability changed with further observation. Conditional probability is basically serving as a stand-in for what we don't know and the fact that we can't solve N-body gravitational problems. The more we know about the asteroid's trajectory, the more we can say about it's potential future paths and the likely hood of it hitting earth. At the end of the day (or the planet), it will either be nudged onto a path that will impact us or it won't, but right now it looks unlikely that it'll happen.
Re:is this too early to predict path ? (Score:5, Informative)
All the models are run according the 'standard dynamic model' at JPL which includes gravity from the Sun, planets, large moons and large asteroids. Perturbations caused by objects outside the solar system are negligible compared to non-gravitational effects such as direct solar pressure and the Yarkovsky effect. These effects are impossible to model without knowledge of material composition, mass and structure, which you can't really get without going there.
However, the uncertainty caused by these non-gravitational effects is very small compared with the uncertainty caused by the fact that we just plain don't know quite where it is and how fast its going. In order to know where the asteroid will be in 2036 to within an Earth radius requires us to know where it is now to within about a meter -- the 2029 close approach in particular magnifies uncertainties incredibly (100x).
These state estimate uncertainties overwhelm any small errors in the dynamic model, and these new and improved probabilities come from refining the current state estimate. So yes, it is still valid to make these kind of predictions. You have to start early (10-20 years) to be able to stop it as well, so its important to keep an early eye on it.
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This post is better than mine and should be modded up.
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This mission, a combined exploration/gravity-tractor mission, is one of the two main projects I've been doing in graduate school. So I guess its a little bit between the two (student/professional). Its definitely more in-depth than a senior design project, in that I've been working on it for 2-3 years. We're working with NASA Ames and some other groups, and have a strong potential path forward for eventual funding and building... so take it as it is.
I've been focusing on the tracking/radio-science portion
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Given that it is supposed to hit in 2036, isn't it too early to be able make accurate predictions ? I mean, I am sure these predicted probabilities will keep changing as it gets closer ( assuming its headed in our direction right now ). I mean, who knows if the path of the asteroid may deviate a little bit due to gravitational pull of different planets/stars etc
Maybe that's why the word 'prediction' was used.
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This is like those COPS shows, where they are following a high speed chase from a helecopter. The announcer is always announcing how they nearly hit the pedestrians, who were on the sidewalk, on the opposite side of the street.
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Yes, we are. Eventually. Might as well get it over with, eh?
Besides, you all are such pessimists. I like to think of it like this. If it hits us, dying will be the one thing that mankind finally comes together and actually achieves, something that everyone, everywhere can be a part of.
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"what do you want for your birthday jimmy?"
"I want to stand directly under the doomsday rock mom!"
Re:How useful is this, really? (Score:4, Insightful)
What is the real use in this? When, within reasonable (I'm not a scientist, but lets use an 85% confidence interval) levels of knowing, would we be able to determine that in fact, yes, this thing is or is not going to hit us?
How's a 99.9996% confidence interval? Not the most obvious way to word it and it doesn't strictly apply, but you could say that in the population of hypothetical asteroid trajectories, 99.9996% of them don't hit earth. More study of its orbit is probably going to increase that number.
Not sure how saying it's odds of hitting us is 1 in 250,000 is less useful than saying it's definitely not going to hit us (with 85% certainty). :)
The article states that they aren't being given the funding to further fund research centers for adequate testing. Politics aside - is there any funding (and more importantly, scientific viability) for preventative action for any of this, or are we just providing confidence intervals of our ultimate doom?
Sadly, no in terms of funding. Even the agencies who could conceivably cobble together something at the last minute aren't getting enough funding. We aren't funding the finding of these object to see if we even need preventative action.
As far as viability... there are quite a few things that would work quite easily with today's technology. But it would take time to actually construct the solution. And they all take time. Virtually none of them would work with only a year before the impact. Even ignoring the silliness of the Armageddon Solution blowing apart a Texas-sized meteor with a nuke, all it would mean is that two California-sized meteors hit the earth instead. The solutions most likely to work are ones where we slowly push (or pull) it out of the way over the course of years.
I'm not really worried about an asteroid that we know about, and are tracking, that looks very unlikely to hit the earth. I'm much more worried about all the objects we don't know about, so we have no idea how likely they are to hit us. My biggest concern is that we discover an object that has a high probability of hitting earth in only a year or two.
More funding for finding and tracking, pls k thx.
Re:How useful is this, really? (Score:4, Interesting)
Certainty is a funny word, but basically, the closer it gets the more confident you are in your prediction because small errors grow to large errors over time.
I would say, without significant funding you'd know for certain in the lead up to the 2029 close approach. During this event, the asteroid will pass within the geostationary satellite belt, and has the potential (1 in 250,000 now) to pass through a 'gravitational keyhole' that corresponds with a return impact trajectory. Note that the likelihood of impact in 2029 is zero (i.e. the 6-sigma boundaries of trajectory estimates are very far from the Earth).
Unfortunately, if you don't do something about it well before 2029, its unlikely you could do anything short of an Apollo-class-plus (Bruce Willis-class?) mission, in terms of funding, uncertainty, and national effort, to stop it. Put simply, its much easier to push the asteroid a kilometer (out of a keyhole) than it is to push it 3000 kilometers, but you have to do it earlier.
If you wanted to do very precise tracking to know if (and where) it was going to impact without waiting for the close approaches, you can do some of it with simply more observations with larger telescopes, and more ground-based radio ranging. However, you're going to get much better results (an order of magnitude) if you send a spacecraft out with a proper beacon. Two or three months in 2021 with this kind of tracking would give you 3-sigma (99%) reliability if it is to impact, and ascertain that it was not if it is not going to. A year of this tracking would tell you where exactly it was going to hit, within about 100km.
Of course, if you're already out there, its not too much more expensive to add the equipment to do a gravity tractor and move it away from a keyhole, since by 2022 it would be very difficult and very expensive to get a mitigation mission put together in time. A combined exploration and mitigation mission is estimated to cost about $350M, and in addition to improving knowledge about the unlikely but potentially imminent threat, would make it much easier to deal with future threats and contribute a lot to our understanding of near Earth asteroids in general. A pure exploration mission might be able to shave off $25M -- the only extra equipment is some Hall thrusters and a longer lifetime. I personally think there is political will for it at relatively low cost (Discovery-class mission), and scientific benefits beyond the mitigation of an admittedly small risk.
(Full Disclosure: Most of these numbers are pulled from a mission proposal I'm currently working on. The details aren't officially published yet, although they are being presented at a conference next week.)
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Any chance of capturing this thing and mining it for things like indium?
-nB
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You'd probably have to apply a few km/s Delta-V (at least) to it in order to do that. All estimates show it entering the Earth's sphere of influence at about 5.87 km/s, which would be reasonable for putting it in orbit, if it were in the right place. Unfortunately, as it moves past the earth it gets sped up and moves on a hyperbolic orbit, it speeds up, so theres no real way to do it just by changing its position slightly (which could be done for ~$300M).
Basically, changing its position slightly in order
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Wow, better odds than winning lotto? But ... but ... someone wins that nearly every single week ... WE'RE DOOMED ... (deep breath) DOOOOOOOOOOOOOOO