Stealth Asteroid Misses Earth

Paradoxish writes: "Gah. According to cnn.com an asteroid hiding in an astronomical blindspot nearly blindsided Earth. The scary part is that scientists didn't notice it until four days AFTER it passed by. Apparently, it would've been similiar to the Tunguska explosion. Scary." As long as they keep missing Earth, we're OK.

Comments

Actually...

[gergi]

The asteroid was installed with a propulsion system and aimed at New Jersey. Unfortunately, due to a conversion factor from metric units, the asteroid missed Earth completely.

Calculations

[nucal]

But don't tell the grandchildren to head to the hills just yet. The odds of a collision are currently 1 in 10 million and could become even more remote with more refined calculations.

If we could just get the calculations more refined, then the asteroids will never hit us.

Re:Calculations

[WolfWithoutAClause]

If you do the precise calculation, you find that it couldn't have hit, because it missed!

Strange that ;-)

Re:Chances are still pretty slim.

[Phosphor3k]

Just remember, every Asteroid is a potential "Britney killer", and should be viewed as such.

I can't live without my Britney Spears.

Oh god no!, NOT the earth...

[Anonymous Coward]

That is where I keep all my stuff....

One of my favourite conspiracy theories

[Edmund Blackadder]

The Tunguska explosion was not caused by an asteroid.

1) there was no crater
2) noone has been able to find any asteroid materials in the area.
3) plants in the area have been discovered to have mutated DNA.

It is quite clear to me that the Tunguska explosion was caused by a miscalculated experiment of the great eccentric inventor Nicola Tesla.

BTW the official theory is that the asteroid consisted of nothing but water, it flew down to close to the surface, and then it exploded. Thats as difficult to believe as the Tesla theory imo.

Re:One of my favourite conspiracy theories

[Alomex]

From space.com:

Almost no one lived near blast site, however, save a few hunters and trappers. No one studied the site until 1930. And while scientists have long presumed an asteroid or comet exploded just above the surface, no consensus has been reached. Some even suggested a miniature black hole did the work.

The object seems to have approached Tunguska from the southeast at about 11 km per second (7 miles a second), the BBC reported.

Why did the asteroid break apart in the air?

"Possibly because the object was like asteroid Mathilde, which was photographed by the passing Near-Shoemaker space probe in 1997," researcher Luigi Foschini told the BBC. "Mathilde is a rubble pile with a density very close to that of water. This would mean it could explode and fragment in the atmosphere with only the shock wave reaching the ground."

A scientific paper on the work will be published in an upcoming issue of Astronomy & Astrophysics.

From bbc.co.uk:

They analysed seismic records from several Siberian monitoring stations, which combined with data on the directions of flattened trees gives information about the object's trajectory. So far, over 60,000 fallen trees have been surveyed to determine the site of the blast wave.

Over 60,000 fallen trees have been surveyed to determine the site of the blast wave

"We performed a detailed analysis of all the available scientific literature, including unpublished eye-witness accounts that have never been translated from the Russian," said Dr Foschini. "This allowed us to calculate the orbit of the cosmic body that crashed."

The object appears to have approached Tunguska from the southeast at about 11 km per second (7 miles a second). Using this data, the researchers were able to plot a series of possible orbits for the object.

Of the 886 valid orbits that they calculated, over 80% of them were asteroid orbits with only a minority being orbits that are associated with comets.

Re:Calculations

[laserjet]

You, my friend, are management material! You will be promoted shortly. Well done.

Re:Chances are still pretty slim.

[coyote-san]

The moon's orbit is used for a couple reasons, most noticably the "lensing" effect both the earth and moon have on close misses. Something that passes this closely is going to have its orbit affected by the gravitational attraction.

As for the impact of the rock, we no longer have the luxury of only caring about the area immediately adjacent to the impact point. During the first Gulf War there was a brilliant flash seen by military satellites from an impact that exploded over the Pacific Ocean. Had circumstances been slightly different the flash would have been seen over the Persian Gulf or Middle East, and it's virtually certain that the flash would have been initially interpreted as a nuclear detonation. (Watching for such flashes is exactly why these satellites were launched.)

If the error was not quickly determined -- and it could be very difficult with another Tunguska-level event where the *only* way to distinguish it from a nuke is the lack of radiation -- then the deaths from the subsequent "retaliation" could easily dwarf the deaths from the initial impact.

I Need My Meds Now

[nickynicky9doors]

Get the editors off the Crack and into detox... You're frickn scar'n me.

Ice Shelf Collapses

Resident Evil

Child Porn

Killer Asteroids

Re:Calculations

[rseuhs]

which hemisphere/continent(s) would have been most likely to have been struck?

This doesn't make sense.

You have to make assumtions - for example change the path, speed and time when/where the asteroid had to be to hit earth. Where on earth it hits, depends on those assumtions and because there are millions of possible assumtions that lead to this result, you get millions of possible targets on earth.

This is like asking what number would have hit a dart player who missed.

since it's spring here now, and the asteroid is probably in the ecliptic.

That would be summer. In spring any location is possible.

Re:Thanks for picking on us, CNN...

[curunir]

Thanks for telling me how dead I'd be if it hit here. Couldn't you have talked about it hitting somewhere where I don't live? Like Kabul, or something? Maybe Baghdad?

They were trying to get you to imagine what the devastation might have been like. Thanks to the presidents Bush, one does not need any imagination to envision what Kabul or Baghdad would look like.

Re:Thanks for picking on us, CNN...

[sharkey]

Couldn't you have talked about it hitting somewhere where I don't live? Like Kabul, or something? Maybe Baghdad?

Or Redmond, Washington.

Re:ELE

[betis70]

>>We have the technology to give us some protection against this type of thing.

Which technology is that, please?

Britney's pontoons.

Are these really near misses?

[Performer Guy]

OK time for some back of the envelope math to counter the hysteria.

461,000 kilometers was the distance it missed by. The projected target area of that circle is PI*R^2 or about 667 billion square kilometers.

Radius of the Earth is around 6360 kilometers give or take. Projected target area of the Earth is therefore about 0.12 billion square kilometers. So the probability this class of object would collide with teh earth is roughly .12/667 or around 1/5600. Then IF it hit it would be more likely to do no damage than not depending on the impact zone.

Of course they don't just count objects inside the 1.2X distance to the moon, range when they scream "near miss". Inside the moon, beyond the moon, they all count for the headlines.

Excuse me for not losing any sleep.

Re:Are these really near misses?

[Performer Guy]

P.S. I know it's bad probability math to post facto take the range and use that in calculations, however, it is correct to say that the chance that any future object passing within that distance would have this probability of hitting gives some simplifying assumptions. The big assumption is that theere is an even poisson distribution of events in the circular target cross section. There may not be for reasons of orbital mechanics and the gravity of the Earth skewing the results. It seems to me that these would likely work to increase the probability of a strike, unless you consider that the Earth hoovering up rocks could skew results the other way, I think when you're this close with a near miss anyway the latter effect is negligable.

Re:This is getting scary

[Reid]

His point, which you seem to have missed, is that there is clearly someone out there pelting us with rocks and garbage.

Re:Whats the point?

[Bob McCown]

What's the point if an asteroid is going to hit what are we going to do exactly?

Soil your undies, perhaps?

Re:Chances are still pretty slim.

[Tackhead]

> Had circumstances been slightly different the flash would have been seen over the Persian Gulf or Middle East, and it's virtually certain that the flash would have been initially interpreted as a nuclear detonation. (Watching for such flashes is exactly why these satellites were launched.)

The flashes from nuke detonations have certain characteristics that the flashes from asteroid/cometary fragment detonations don't.

(That said, the nuke-detecting satellites are doing a good job of keeping track of upper-atmosphere flashes from asteroid/cometary fragments. To the extent that such data can be given to NASA folks, we're getting some good science out of these things.)

Yes, a human observer on the ground may erroneously conclude they've been nuked, but any rational chain of command involving release of nuclear weapons will include verification that the supposed nuke really was a nuke and not an unfortunately-timed meteorite.

(Unfortunately, convincing the other side's troops that we hadn't developed some sort of new superweapon might be another story. The less technologically-advanced the opponent, the more the risk that they'll be able to understand the evidence that it was just Really Bad Luck.)

Thankfully, the odds of asteroid impact itself are pretty slim, and I'm much more worried about those odds - anywhere on the planet - than I am about the rock hitting the Wrong Place at the Wrong Time.

(Also thankfully, the solution to both problems is the same - a bit more spent on gear to watch for rocks, and assloads more spent on R&D into cheap, heavy-lift capabilities so we have a hope in hell of deflecting them when/if we find one with our name on it. If we never find a rock with our name on it, we've got a heavy-lift capability to make space tourism, offworld solar power stations, and eventual colonization a reality. Win/win.)

Re:Whats the point?

[cperciva]

if an asteroid is going to hit what are we going to do exactly?

Evacuate Atlanta?

Re:Meteorites DO Screw Stuff Up

[FFFish]

Damn, can you imagine what a cow looks like after it's been hit by a meteorite? SPLAT!

I'd probably pay to see that.

Not that I have anything against cows, mind you.

Re:Thanks for picking on us, CNN...

[david duncan scott]

OK:

"If it were over a populated area, like Baghdad, it would have basically flattened it," said Gareth Williams, associate director of the International Astronomical Union Minor Planet Center in Boston, Massachusetts, "but our calculations show that one fragment, about the size of a grapefruit, would hit Blackwulf square in the face, killing him instantly"

Better?

Torino Scale (used to classify collision threats)

[volpone]

If you're interested, check out nasa.gov's description of the Torino Scale , the method in which the scientific community classifies an object's likelihood of striking and damaging the Earth.

The rating goes from zero (the object is certain to miss the Earth) to ten (the nasty asteroid thingy is definitely going to "cause a global climatic catastrophe"). Read it, it's very unsettling...

Does anyone know what Torino rating this most recent near-miss was?

Came from the direction of the sun?

[guttentag]

The space boulder passed Earth within 288,000 miles (461,000 kilometers) -- or 1.2 times the distance to the moon -- on March 8, but since it came from the direction of the sun, scientists did not observe it until four days later.

In other news, President Bush has declared the sun to be part of "the axis of evil."

"My advisors have just informed me that the sun has been hurling dangerous, radiation death rays at the United States and its friends for millenia. And they have a 'solar flare' weapon they use to disrupt our electronics."

"Mark my words. We will smoke them out of their holes and wipe them off the face of the planet," Bush stated, before a reporter pointed out that the sun is not on Earth. "It don't make no difference -- don't interrupt me with the politics of details, son. We're still going to hunt them down and put a stop to them."

The president refused to answer questions about whether he plans to detain the sun in Cuba.

Re:Calculations

[Tosta Dojen]

This is like asking what number would have hit a dart player who missed.

I dunno... I once saw an 8 come down off the board and start beating the crap out of a dart player who missed his shot entirely. The dude was slightly drunk, too, so the 8 was really trashing him before the rest of us got them apart. Of course, the 17 is pretty irritable too -- I wouldn't be surprised if one of them ever gave somebody a smack in the head.