Asteroid to Make Closest Recorded Pass to Earth

unassimilatible writes "A 100-ft diameter asteroid will make the closest (26,500 miles, or about 3.4 Earth diameters) pass of earth ever detected in advance today, NASA reports. Asteroid 2004 FH's point of closest approach with the Earth will be over the South Atlantic Ocean. Using a good pair of binoculars, the object will be bright enough to be seen during this close approach from areas of Europe, Asia and most of the Southern Hemisphere. While we are in no danger this time, it is good to know NASA's LINEAR guys are on the job, for when that Death Star-sized object pays us a visit."

Huh?

[dolo666]

"100-ft diameter asteroid" ... "that Death Star-sized object"
The Death Star was bigger than 100 ft dia! Maybe the miniature Lucas used was that size? :-) If LINEAR can pick up 100ft dia objects, anything bigger would be easy. Now I can feel safe until this one veers off due our shoddy ozone, and smacks down on my hometown.

Re:Huh?

[TheRealMindChild]

Honestly, who cares? If an asteroid hits, I promise, you won't feel a thing.

Re:Huh?

[Fishstick]

Really. Being hit by a planetkiller that causes extinction of humans on the earth doesn't worry me. Who will miss us?

My biggest fear is that we will be hit by a not-quite planetkiller that will cause enough devastation to ensure the survivors live in misery for the rest of their (short) lives. That would suck.

The big one...

[turnstyle]

"it is good to know NASA's LINEAR guys are on the job, for when that Death Star-sized object pays us a visit."

So that we can all enjoy the peace-of-mind of knowing that we're all about to die, in advance. ;)

Re:The big one...

[tuffy]

So that we can all enjoy the peace-of-mind of knowing that we're all about to die, in advance. ;)

We're all going to die eventually. But throughout all of history, mankind has yearned for the day when we all get to die at the same time. It's not as scary as dying alone, or as scary as the thought the world will go on without us.

Re:The big one...

[turnstyle]

"We're all going to die eventually."

Speak for yourself.

Re:The big one...

[Wog]

Seriously.

I plan to live forever.

*looks at watch*

So far, so good!

Re:The big one...

[cherokee158]

You're a lot of fun at parties, aren't you?

Re:The big one...

[Xzzy]

You're right, the scary part about armageddon is actually surviving the initial event, and being forced to adapt your strategy instantly.

Talk about the ultimate episode of survivor.

Re:The big one...

[mwood]

Well, if they give us 10-20 years' warning (which is not at all absurd, given that these rocks are not under power and thus utterly predictable) we can mount an expedition to deflect the thing, crush it to small pieces that shouldn't cause serious trouble, or just mine it out of existence.

(Hey, a few megatons of nickel-iron might not make us all rich, but it could defray at least *some* of the expense of saving our lives. Cost recovery is good.)

Re:The big one...

[Jesus 2.0]

Won't work:

Kent Brockman: With our utter annihilation imminent, our federal government has snapped into action. We go live now via satellite to the floor of the United States congress.

Speaker: Then it is unanimous, we are going to approve the bill to deflect the aster...

Congressman: Wait a minute, I want to tack on a rider to that bill: $30 million of taxpayer money to support the perverted arts.

Speaker: All in favor of the amended asteroid-slash-pervert bill?

(Congress): BOO!

Speaker: Bill defeated.

Kent Brockman: I've said it before and I'll say it again: democracy simply doesn't work.

Re:The big one...

[hpulley]

Well, if they give us 10-20 years' warning (which is not at all absurd, given that these rocks are not under power and thus utterly predictable) we can mount an expedition to deflect the thing, crush it to small pieces that shouldn't cause serious trouble, or just mine it out of existence.

Hmm, except that this one was detected Monday [space.com]. 3 days notice isn't enough to do anything. Larger ones should be detected earlier but how much earlier?

Crushing it to small pieces won't help.

[Ralph Spoilsport]

It's all mass. A billion ton rock flying through space at 50,000 miles per hour hitting the earth all at once is mechanically no different from a billion tons of loose sand flying through space at 50,000 miles per hour hitting the earth all at once.

"Oh - we'll blow it up. That'll make it go away."

Wrong. Mass and inertia are mass and inertia. The results might be a bit different - a dense solid object will tend to penetrate the surface a bbit deeper, but the heat generated from a billion tons of sand tra

Re:The big one...

[Mateito]

So that we can all enjoy the peace-of-mind of knowing that we're all about to die, in advance.

I wouldn't worry, if its just an asteroid, Bruce Willis will die to deflect it.

If, however, its a shitload of Vogons, we are fucked.

Re:Huh?

[aipotsid]

...NASA officials say they detected the asteroid after it hit a parked car in Queens....

Perhaps you should actually read what it says

[hpulley]

...While we are in no danger this time, it is good to know NASA's LINEAR guys are on the job, for when that Death Star-sized object pays us a visit.

The heading doesn't say the current 100 ft object is Death Star-sized. It says the author is glad LINEAR will be on the job for the time when one that large comes by.

Re:Huh?

[hankwang]

The Death Star was bigger than 100 ft dia!

The death star in Star Wars was able to shatter a planet to pieces. One can calculate that the energy needed to overcome the gravitational pull is about G*rho^2*r^5, where G=the gravitational constant, rho the planet's density, and r its radius. For an earth-sized planet, that amounts to 1e30 J, or 6e13 kg of matter to be converted into energy. If the Death Star were completely consisting of concentrated antimatter, then it would have been 3 km in diameter and be able to fire exactly one shot. Yes, that is more than 100 ft. :)

Lucky

[Space cowboy]

According to the article there are normally 2 of these every year. It seems a bit tongue-in-cheek to say "The important thing is not that it's happening, but that we detected it" [Chesley]. They were lucky, that's all.

It *will* give them a chance to study the thing as it passes, since all the other ones were only detected after they'd gone (and presumably therefore couldn't be easily studied). If it's close enough to see with binoculars, it ought to be possible to resolve quite well in a good optical 'scope.

The other point I guess is that it's only 100 ft across (why not 30m ?) so it would have burnt up on entry into the atmosphere, but still, good to know about these things. An asteroid that big would make quite some bang on entering the atmosphere, I reckon :-)

Simon

Re:Lucky

[lukewarmfusion]

I remember reading about NASA's (and others') ability to detect these in advance... apparently this science has improved immensely over the last ten years.

But you do bring up a good point - if this object would have hit Earth, would it have burnt up, or would something dangerous remain?

Much smaller items hit Earth all the time - they don't get burnt up completely. Of course, many end up the size of maybe pebbles or baseballs...

Re:Lucky

[sponge_absorbent]

it depends on the composition of the object and the angle and speed at which it enters the atmosphere.
I imagine that if it were a roughly spherical, dense, metallic object it would have a good chance of hitting the surface.

Re:Lucky

[Bill, Shooter of Bul]

What about the ones that do not completely burn up in the atmoshpere? Does anyone know how large those started off as? Every now and then you hear about a meteor hitting someones house and putting a hole in the roof. I'm just wondering if those are these 100 ft objects that make it through somehow, or are they larger and more rare than these.

Re:Lucky

[Catbeller]

A hundred foot object would punch through at many miles per second, so time to ablate would be short. A few seconds in the atmosphere at most. (The scenes in Armaggedon of rocks tumbling down were silly; in reality you would barely have time to blink before you were dead from the shock wave. FLASH: blink: dead) It may break up into fragments, which doesn't help much in the kinetic energy department, IE we still get hit with tens of thousands of tons at many miles per second.

Little objects like a grapefruit

Re:Lucky

[Catbeller]

The rock would be moving at something like Mach 30 - at any rate at miles per second. The atmosphere is around 60 miles deep. It would be a blink. For it to be faster than a blink, for you, you'd have to know it was coming, be focused on the spot in the sky, and follow it. 60 miles/7 mps (supposing)= 9 and a fraction seconds to boom. Then you'd wait for the supersonic shock wave. Depends on how close you are to the impact(s). If you don't know it was coming, you'd maybe see a short flash of light, followed by death in a second or at most a minute or two. As for my Armageddon reference, I belive I was dead on. If you were in Manhattan, ground zero, you'd have seen a brief flash followed by a supersonic shock wave in less than a couple of heartbeats. It'd be like nuclear detonations, only without the radiation. As Heinlein said in The Moon is a Harsh Mistress, just like a sparks from a hammer. Just a really BIG hammer.

And shock waves aren't sound, so they can move quite quickly. The air itself would be moving at hypersonic speeds, mixed with vaporized solid matter from ground zero. Dust, really fast dust, and gravel.

Re:Lucky

[AJWM]

It'd be like nuclear detonations, only without the radiation.

Oh, from an explosion like that, you'll get radiation -- X rays and such from the high temperature plasma. Just not us much radiation (no neutrons) as from a nuke, and no fallout. (Well, not radioactive fallout. Plenty of dust.)

Re:Lucky

[Slowtreme]

Would this really burn up? Skylab was less than 50ft long and hollow inside. Many of it's parts made it to the ground. I'd image a solid rock hitting our atmosphere at that speed would not lose too much mass on the way in and do some pretty significat damage if it hit near a populated area.

This one is flying pretty darn close for comfort.

Re:Lucky

[0x41]

Skylab was going 100 times slower than this asteroid, hence it didn't burn up.

Re:Lucky

[tiled_rainbows]

But Skylab wasn't going as fast - Celestial mechanics isn't my strong point, but something falling from a gradully-decaying orbit around the Eath (eg Skylab) won't be going half as fast relative to the Earth as something aproaching perihelion on a huge elliptic orbit round the sun (eg an asteroid) - things on elliptic orbits go faster the closer they get to the thing they're orbiting. Conservation of angular momentum or something.

And as Skylab wasn't going as fast, it wasn't heated up so much in the atmosphere, so more bits of it reached the surface than most meteorites.

Re:Lucky

[HeghmoH]

The speed doesn't make as much of a difference as you'd think. You're going faster, but you also have much less time for the heating to have any effect. The direction of travel is also important. If the asteroid were traveling perpendicular to the atmosphere, the parts of the atmosphere that matter are only about 50 miles thick. Typical combined speeds for an object coming from solar orbit are in the range of 20-30 miles per second. In that case, the asteroid would only have about two seconds to completely

Re:Lucky

[GooberToo]

Mod the parent back down. The AC which already replied and was marked as flambait is right. This guy is an idiot. The only exception where his statement might hold water would be if the object were solid water...and then, maybe. And then, it wouldn't be because of "pressure differences", it would be because of super heating, causing steam to form inside, causing it to explode.

Re:Lucky

[DigitumDei]

Not quite pressure differences inside.
Taken from the following NASA article. [nasa.gov]

Asteroids move faster than the speed of sound in Earth's atmosphere. As a result, the air pressure ahead of a fireball can substantially exceed the air pressure behind it. The difference can be so great that it actually crushes the object

Re:Lucky

[mikerich]

you are an idiot, right? pressurce differences inside a solid mass?

No he's not.

It depends if it solid rock. many stony asteroids are apparently spongy having once contained volatiles that have subsequently been lost to space. These fragile objects will disintegrate in the atmosphere as atmospheric deceleration crushes them.

Its for this reason that carbonaceous chondrite meteorites - the black ones with the exciting organic compounds are relatively rarer on Earth than their abundance in space would suggest. We're regularly encountering them, they just don't make it through to the surface.

Having said that a 25m chunk of anything disintigrating in the atmosphere would produce a blast in the high kiloton, low megaton range. One of these smashing into a city would be a catastrophe.

And they seem to be more common than we think - there is obviously Tunguska in 1908, but then there are reports of something exploding over the Amazon basin in the 1930s, the more than 100 small impacts that hit Sikhote-Alin in Russia in 1947 and the most recently uncovered biggish impact at Wabar in Saudi Arabia - a Hiroshima-sized explosion in either 1863 or 1891 (there is no agreement on the date, since Arabic scholars saw two bright meteors heading in that direction on different dates, it's only recently that scientists have been able to determine the relative youth of the Wabar craters).

Best wishes,
Mike.

Re:Lucky

[K1-V116]

The meteor that made Barringer Crater in Arizona (1.6k across and nearly 200m deep) was ~45m in diameter -- only about 50% wider and roughly twice the mass of the one detected. This rock _could_ have spoiled someone's day....

Re:Lucky

[mikerich]

50% wider and roughly twice the mass of the one detected

If both bodies were the same shape the larger would have eight times the volume.

As for mass, Barringer was definitely iron which makes it comparitively rare - less than 6% of observed meteorite falls are iron, yet they make up over 80% of collected meteorites. The latter number is easy to explain - iron meteorites don't look anything like rocks found on Earth, the much more common stony meteorites (which form over 80% of all observed falls) are very hard to distinguish from the stuff on the ground.

More than likely this is a stony body which would give it a much lower density - round about 3.6 gcm-3 as opposed to 7.9 gcm-3 in iron meteorites.

Having said that - a lump of stone that size hitting the Earth would still be comparable to a hydrogen bomb going off - as you say it would have spoiled a whole lot of people's days.

Best wishes,
Mike.

Re:Lucky

[AJWM]

50% wider and roughly twice the mass of the one detected

If both bodies were the same shape the larger would have eight times the volume.

Er, 1.5^3 = 3.375, not eight. Other than that you're doing fine ;-)

Solar system collisions simulator

[copper]

Plug in some numbers and find out [umd.edu] :)

copper

Some Deductions

[LaCosaNostradamus]

Look at the facts and deduce your answer. I didn't have time to googleconfirm any of this, so I assume the risks of some numerical errors.

Man-made objects that come down are very light, hollow and fairly slow. Asteroids and comets are guaranteed to be the opposite.

Asteroids are 2 different types: metallic, stony and finally "carbonaceous chondrite". The metallic are essentially chunks of nickel-iron. The stony are just rock. And the CC types are rocky but composed significantly of some ices and

Re:Lucky

[Eevee]

Except if you read the NASA site [nasa.gov], they use metric measurements, then give the "stupid american" measurements. You have to blame the Associated Press for not using metric when they reported this on the wire.

For those too lazy to click the link, this is the relevent quote from the press release.

...is roughly 30 meters (100 feet) in diameter...

Yay!

[MalaclypseTheYounger]

Time to dust off the "Thumb" and see if I can get off this godforsaken mudball.

Is the asteroid construction-equipment yellow, with lots of lumps?

It's the one you don't see or hear that gets you

[Anonymous Coward]

If you hear the thunder, that means the lighting didn't kill you.

If you hear the gunshot, the bullet didn't kill you.

If you smell the engine burning, the car wreck didn't kill you.

If you are still reading, the asteroid missed.

Bennifer, You're our only hope!?-SarcarticVersion

[mynameis (mother ...]

Guess what everybody: There is another asteroid heading right for us. NEA 2004FH is due to arrive around 5pm EST today. Recently Discovered [nasa.gov], the object is ~30kmmeters [google.com] across, and will pass within 30k miles of earth. "Scientists look forward to the flyby as it will provide them an unprecedented opportunity to study a small NEA asteroid up close." Also worthwhile, the view showing it's orbit [superimposed over our's] notes "The locations of the asteroid and Earth are indistinguishable at this scale."

• Which

Impact risks

[xlation]

For a long list of Potentially Hazardous Asteroids (PHAs) see: http://cfa-www.harvard.edu/iau/lists/PHACloseApp.h tml

Also, for information on assessment of the
impact risks using the Torino Scale, which is
kinda like the Richter Scale for impact risk,
see: http://neo.jpl.nasa.gov/risk/

And when this is a threat we will...

[jtwJGuevara]

or when that Death Star-sized object pays us a visit.

At which point we will hide behind our moon and send a squadron of George Bush sponsered space monkeys to penetetrate it's interior and fire photon blasters into a two meter hole to destroy it and save the earth.....

Re:And when this is a threat we will...

[operagost]

Whereas if John Kerry wins the election, the earth will be destroyed waiting for the U.N. to decide on an appropriate "police action".

Re:And when this is a threat we will...

[Mick Ohrberg]

...and fire photon blasters into a two meter hole...

Why not 6 ft? :D

Oh Great...

[hardcode57]

they'll be able to tell us in advance we're all going to die and there's damn all they can do to stop it. Still, I guess that's a better excuse for a really reprehensible party than most:)

But ... isn't it tracking?

[Anonymous Coward]

Will it miss? Hollywood always taught me that killer asteroids come equipped with state of the art in tracking with the cross hairs firmly locked onto an American city like New York.

Hollywood special effects must have made a mistake this time around.

And if...

[ForestGrump]

it was going to hit the earth and cause a massive extinction of the human race...
I highly doubt we will be told about it. Instead, our world leaders will gather in a cave somewhere with their mistresses and 500 years worth of refried beans...that ought to keep the human race going.

-Grump

Re:And if...

[Hieronymus Howard]

Imagine what the cave would smell like after 500 years of refried bean consumption.

Come to think of it, I can't think of a better fate for our 'leaders'.

Re:And if...

[YetAnotherAnonymousC]

500 years worth of refried beans.

And don't forget plenty of Rico's nacho cheese [ricos.com]. It's the profitmaker!

Re:And if...

[pavon]

Why would our world leaders have anything to do with it? It is the scientists that know what is going on, and the people that they would tell, in this order would be 1) other astronomers, 2) their families 3) the politicians 4) the journalists. There would be enough people that knew about it before the politicians that it would be impossible to cover up even if they wanted to.

Re:wonderful...

[bellings]

Intelligent life evolved from chimp-like creatures once. It could happen a second time.

um and?

[tomstdenis]

Ok so in the future we will know when a 100km diameter asteroid is gonna hit earth. Problem is, there is shitall we can do about it. I personally would rather not know when my time is up then sit and worry..

oh wait... screw that. If I knew the end of time was coming I'd l00t! Cuz that's what all good capitalist swine do!

Tom

Re:um and?

[Lebannen]

Jupiter being 140km?

Crikey, that puts a 2km cycle to work in perspective. No wonder I'm always turning up late!

100km?

[Eevee]

Dude, you need to get out more often. 100km is about an hour's worth of driving at highway speeds (or about 40 minutes worth if there aren't any cops out.)

Basically, you're off by about three magnitudes: Jupiter isn't 140km in diameter, it's around 143,000km.

Dammit

[Viggeh!]

I cant believe its gonna miss! Now i cant throw my wicked end-of-the-world orgy-party! *sigh*

Re:Dammit

[Powercntrl]

I cant believe its gonna miss! Now i cant throw my wicked end-of-the-world orgy-party! *sigh*

Wouldn't it suck if the world was really going to end and no girls showed up to your orgy-party? Order your REALDOLLS today while there's still time!

Gravitational Effects?

[fishdan]

Any astronomers out there know if this will have a measurable gravitational affect on the planet? I know it's awfully small on a planetary scale -- but it's mass might be great. And, as I understand it, we're pretty good at detecting gravitational shifts [space.com]. I know there won't be high tides or coastal flooding -- just if an object that small will have ANY noticable effect.

Re:Gravitational Effects?

[kalidasa]

It's 30 m across, and the earth is 12,760,000 m across, volume is pi r^2, assuming the same density, and gravity is proportional to mass - probably not. If we could do that, we wouldn't need line of sight radar - we could just track airplanes by their gravitational effects without line of sight.

Re:Gravitational Effects?

[TGK]

Er.... volume is 4/3 pi r^3. pi r ^ 2 is area.

You want to know

[purduephotog]

how much the asteroid will tug the earth?

Are you serious?

100 foot diamater. Thats smaller than bunker hill.

20 busses parked together and loaded with people from Overeaters Anonymous would probably have more mass...

Re:Gravitational Effects?

[cperciva]

100' diameter ==> 15m radius ==> around 15000 m^3 ==> somewhere around 5x10^7 kg if it's rock.

26500 miles is around 4000 times further away from the surface of the earth than the 35,000 feet at which planes fly.

So the gravitational effect this rock will have at the surface of the earth is around the same as the effect from a 3kg bag inside a plane flying overhead. Probably not noticable. :)

Re:Gravitational Effects?

[ThinWhiteDuke]

You forgot Gauss's theorem. You should estimate the gravitational effect by measuring distances to the center of the earth, not its surface.

Tides are caused by the gravitational effect of the sun and the moon on the whole surface of the earth, not on a single point. Let's assume a flat distribution of water on earth's surface. Gauss says that the gravitational force applied to a sphere is equal to the force applied to the same mass positioned at the center of the sphere.

Now, the relevant comparison wou

Re:Gravitational Effects?

[ThosLives]

Well, it's not that hard to figure out. Assume the 100' diameter (30.48m) thing is a sphere made of solid steel (density ~8000 kg/m3). That sphere has a volume of 14,827 m3, so would have a mass of ~118.6e6 kg. At a distance of 26,500 miles from earth's center, it will exert a force of 2.6e7 newtons (about 3000 tons) on the earth. This would make the earth accelerate toward the asteroid at only 4.3e-18 m/s2 (the asteroid, though, accelerates toward earth at a whopping 0.2 m/s2).

If you were standing on the

Hmm

[Czernobog]

Either there's an ever increasing number of asteroids coming ever closer to Earth (unlikely methinks) or this is truly indicative of how blind we have been all thse years to what was happpening in space.
Sort of puts our achievements into perspective...

Re:Hmm

[Khomar]

Either there's an ever increasing number of asteroids coming ever closer to Earth (unlikely methinks) or this is truly indicative of how blind we have been all thse years to what was happpening in space.

Or God is sending us warning shots across the bow.

Hey!

[lukewarmfusion]

"Using a good pair of binoculars, the object will be bright enough to be seen during this close approach from areas of Europe, Asia and most of the Southern Hemisphere."

Great. Now even the Universe hates America.

Re:Hey!

[lukewarmfusion]

Do these kinds of "asteroid misses Earth" stories make anyone else feel like this is just one big "dunk tank?"

Re:Hey!

[pe1rxq]

Its pissed of by hollywood's type-casting of asteroids.

Jeroen

Alien Rock

[PRES_00]

The first one is not a miss, it's just used for calibration. The second will be create a 10 cm crater but its organic content will exterminate all life on this miserable rock.

Re:Alien Rock

[johnalex]

No, you've forgotten: A firefighting cadet, two college professors, and a geeky-but-sexy government scientist [imdb.com] will destroy the organic life with dandruff shampoo.

This is sserious

[cda]

Section of an IAU Statement prepared by Dr. David Morrison, 14 March 1998
The International Astronomical Union's (http://www.intastun.org/) list of 108 known ''potentially hazardous objects,'' or PHOs.
Most of the asteroids that could strike the Earth and cause a global catastrophe have not yet been found. For the year 2028 (or any other year) the chances of an unknown asteroid hitting the Earth are much greater than the chances of this particular asteroid hitting. If an unknown asteroid should hit us, we would likely have no warning at all. The first we would know of the danger is when we saw the flash of light and felt the ground shake. At the current rate of discovery, it will take more than a century to find 90% or more of the objects this large with Earth-crossing orbits. For better or for worse, the astronomers who carry out these searches and orbit calculations work in the public eye. The idea that a threatening asteroid could be kept secret (or that anyone would want to keep it secret) is ludicrous.
For further information see the NASA asteroid and comet impact hazard website at:

also to be noted

[cda]

from http://impact.arc.nasa.gov/

THE SAGA OF ASTEROID AL00667 = 2004 AS1

Brian G. Marsden (from CCNet, 15 January 2004)

"That this latest PHA should have generated so much heated discussion on numerous mailing lists and the internet on the basis of four observations covering a time interval of one hour on the morning of Jan. 13 is surely quite amazing. On the routine arrival of the night's LINEAR data at the Minor Planet Center at 5:15 p.m. EST that day, the usual computations on them were quickly done, a

Stock up on Cambels Soup

[gt25500]

At this rate of asteroids getting closer and closer, we're due for impact next month!

Damn it,

[Anonymous Coward]

will one hit us already, the suspense is killing me.

I always wanted a seaview from my city apartment.

How far away?

[pesc]

A 100-ft diameter asteroid will make the closest (26,500 miles, or about 3.4 Earth diameters)

If "feet" or "earth diameters" are not your preferred units of measurement, what the article is trying to say is that the asteroid is about 90m in diameter and will pass the earth at a distance of about 42600 km.

Re:How far away?

[pesc]

Ouch! meant 30m in diameter. *blush*

Re:How far away?

[interiot]

Also note that geosynchronous orbit [www.sfu.ca] is at 42,250 km. Which means this asteroid is potentially coming very close to some of the satellites we've put up there.

Re:How far away?

[TigerNut]

They didn't say anything about the relative angle at which the asteroid would be approaching. Geostationary sats occupy a fairly narrow belt around the equator (see, for example, this applet - assuming your computer is less Java-hostile than mine) 3D satellite simulator [nasa.gov]

Any object approaching from angles significantly above or below the equator will have only a very small chance of nailing a geostationary satellite.

Distributed computing?

[bigattichouse]

Is there a LINEAR@Home type thing? I would prefer to use my spare cpu cycles protecting life on earth. "meta-environmentalism" I guess.

Distributed seeing

[jmichaelg]

The computations aren't that hard given the quality of data they have to work with. A lot of these objects are spotted once and never seen again for a variety of reasons. What's needed are more data, not more cpu cycles.

Amatuer astronomers continue to make significant contributions to the field. It was an amatuer who first noticed that al0667 might hit the earth and it was another amatuer who recorded the key observation that placed the same object on a safe trajectory. If you're serious about wanting to he

I am so happy !

[tgrasl]

"it is good to know NASA's LINEAR guys are on the job, for when that Death Star-sized object pays us a visit."

What are they going to do ? Send Bruce Willis up to save us ?

The real threat of these small ones

[bwallace]

Imagine if you will that this thing actually penetrated the atmosphere. Okay - so it wouldn't reach ground, but there would likely be a fairly significant blast (this one is only about 1/3 to 2/3 the diameter of the Tunguska object, and that one made a hellish blast).

Imagine now that this penetrated the atmosphere over, say, North Korea, or the Sea of Japan, or somewhere over India/Pakistan. It is not much of a stretch to suggest that this might precipitate a limited nuclear exchange. Not a for-sure, but enough of a "could-be" that somebody's day could be ruined.

This is why it is important to look for (small) potentially hazardous objects - not because they will (directly) cause the extinction of the human race, but because they could precipitate an all-too-human conflict, just out of ignorance.

Note also that, as good a job as LINEAR and others do, there is a class of asteroids that are damn hard to see form the ground - the "Aten"-class asteroids, which orbit mostly inside earths orbit and thus come at us from out of the sun. These ones also need to be catalogued and a watchfull eye kept out for.

So, when people start to ask the value of asteroid hunting, bring up these ideas. Sadly, nuclear war is a much more real threat to most people compared to mass extinction.

This one *does* orbit inside the Earth's orbit.

[djmurdoch]

Note also that, as good a job as LINEAR and others do, there is a class of asteroids that are damn hard to see form the ground - the "Aten"-class asteroids, which orbit mostly inside earths orbit and thus come at us from out of the sun. These ones also need to be catalogued and a watchfull eye kept out for.

The JPL web page about this asteroid [nasa.gov] gives a diagram of its orbit, and it is mostly within the Earth's orbit. They don't say whether the picture is the "before" or "after" picture --- the pass near Eart

slide rule, anyone?

[malia8888]

From the article The asteroid's close flyby, first spied late Monday, poses no risk, NASA astronomers stressed. "It's a guaranteed miss," said astronomer Paul Chodas, of the near-Earth object office at NASA's Jet Propulsion Laboratory.

Makes me hope Paul at the lab made good grades in math:P

3 earth diameters.. that's close enough to ..

[intertwingled]

If we hadn't wasted billions of dollars on the Space Shuttle we might have the technology now to travel out to that asteroid, and park it in earth orbit. If it is mostly metal then it would be a bonanza grab. And if not, it would make a fine space station. *sigh*

Upon closer examination...

[Slur]

...it became apparent their initial impression had been wrong. Said they: "That's no asteroid. It's a space station."

100 ft may seem small, but ....

[innerweb]

From what I am reading in the articles on the net, 100 feet can still create some serious, albeit localized damage. If this bad boy were to hit over the ocean, probably not much, but over land, it could cause serious local destruction. Anyone out there serious about their astronomy?

The Tunguska Blast [sciam.com] over Siberia was an object about 100 meters in diameter. Sure it burned up in the atmosphere, but it was devastating to the ground anyway. This article also mentions that at about 50 meters, these rocks make it through the atmosphere and can do serious localized damage. So, since 100 feet converts [teaching-e...-japan.net] to is 30.48 meters, this rock would more than likely to have an effect that we will notice on the ground.

For further reading, here is a site [pibburns.com] that has already compiled links and information And, of course, the Yahoo listings [yahoo.com] on Earth Impact information online.

InnerWeb

Re:100 ft may seem small, but ....

[Glock27]

According to the "Solar System Collisions" page:

---begin results---
YOUR COLLISION PARAMETERS

Projectile: Rocky Asteroid
Diameter: .03 kilometer(s)
Velocity: 20.0 km/s
Target: Earth

RESULT: Explosion 5-20 km Above Tibet [note: they made this part up;)] in Asia!!
Energy Released = 2 MT (MegaTons of TNT)
(Largest Nuclear Weapon: 100 MT)

A collision this large occurs roughly once every 58 years.
---end results---

Now, we don't know much about this object's composition, so it could be iron. If so, and if it were m

Meteor Crater

[Anonymous Coward]

An 80ft asteroid caused Meteor Crater at 1.2km wide. A 100ft one may likewise not burn up. Meteor Crater [nasa.gov]

Calin

[BlueTooth]

"Near miss? It's a near hit! A collission is a near miss. BOOM! Look, they nearly missed"
-George Carlin

A not-entirely offtopic story

[Unknown Kadath]

I have an acquaintance. Call him...Jack. (Name changed to protect the obsessed.) Jack has picked two goddamn things about which we can do absolutely nothing to freak him out: near-Earth asteroids and megavolcanoes. He was my friend's boss for a while, and we ended up at a lot of the same parties and restaurants and such. He would always corner me, because I was usually the only aerospace engineer there, and talk for hours about how life as we know it was shortly going to be wiped out by a really big rock, and how this was the greatest threat ever to face humanity.

After this happened a couple of times, I told him that I was comfortable playing the odds that an extinction-level event would hold off for the couple of centuries it would take us to actually be able to deal with it, given the scale of geologic time time to human achievement. He nearly spit his beer across the room.

In conclusion: Space is really big, really empty, and some people just need things to worry about.

-Carolyn

So, a question for the astronomers

[Walkiry]

That good fellow is going to pass quite close to earth. Now, the question I have is, how close does an asteroid such as this have to pass so that it is captured by Earth's gravitational field and become a satellite? It could be useful to have a big rock in stable orbit.

I'd hate to be a

[Gr8Apes]

geo-synchronous satellite. 26km is just about their orbit. Shouldn't we try to protect them?!?

luckily we have gen-x'ers

[enrico_suave]

We have a whole fleet of people who have grown up practicing on the USS Triangle using vector based simulation software (asteroids).

e.

Almost geosynchronous height!

[pvera]

Back in my Army SSDC days our main geosynchronous comms satellites were on a 22,300 mile orbit. This thing is going to pass just above. Suddenly these 26,500 miles don't look *that* far to me.

Are we on the bullseye in 2053?

[Liquor]

I may be reading the impact risk table [nasa.gov] wrong, but right now it seems to say that the distance it will miss by on Jan 12, 2053 is .01 earth radius. I assume that this means that we are very near the center of the area of uncertainty about where it will impact, and that the areo of uncertainty is currently extremely large.

On the other hand, I seem to recall that most previous predicted near misses had us further out from the centroid, and as the orbital data was refined, the area of uncertainty shrank until we were no longer in it. I suspect that reducing the uncertainty without changing the orbital prediction would raise the calculated risk with time.

As I read it the impact energy would be about equal to a 300Kiloton bomb. Not a particularly large hazard area if it came straight down (it probably won't), but it would certainly be big enough to mess up somebody's day. For that matter, has anyone actually run a prediction of what the effects (thermal, weather, etc.) would be from a grazing strike where it travelled parallel to the surface for a long way before breaking up or leaving the atmosphere?

We came pretty close.

[icejai]

It takes the earth about 6 minutes to travel a distance equivalent of its own diameter.
So basically, to avoid a direct hit, the the timing of of a near-earth-asteroid only needs to be altered by 6 minutes over the course of its orbit(s).

What I can't get over is that we *missed* this asteroid by only 12 to 18 minutes!

That's just crazy.

Re:NASA's on the job. Can they save the world?

[glpierce]

I suppose our best "defense" would be to evacuate as much of the impact area as possible. Nuclear winter theories aren't as respected as they used to be.

Re:NASA's on the job. Can they save the world?

[shibbie]

I find it amusing that a threat to everyone thats a far bigger catastrophe than terrorism has no defence (I'm British, this is our spelling 8P ). In all likelyhood (imho) its the biggest continents that will suffer the most. The UK will either just be wiped out or get missed entirely (we've always had bad weather)...

Re:Training material?

[jridley]

We have no technology that can deflect an asteroid that's going to hit anytime soon. We can't even GET to an asteroid that's going to hit us unless we detect it several orbits back. If it's going to hit soon, then it's so far away that we can't get to it with any booster that we currently have with enough mass to make any difference.

Hell, we don't even have a booster that could get people to the moon anymore, and even if we still had operational Saturn V's, they still wouldn't boost enough mass out of Ea