Russian 'meteor' was actually a tiny asteroid, NASA says (45 feet across, 10,000 tons & 40,000 mph)

The Los Angeles Times ^ | February 16, 2013 | Monte Morin

[2ndDivisionVet]

At a news conference Friday, NASA scientists said the object that exploded over Russia was a “tiny asteroid” that measured roughly 45 feet across, weighed about 10,000 tons and traveled about 40,000 mph.

The object vaporized roughly 15 miles above the surface of the Earth, causing a shock wave that triggered the global network of listening devices that was established to detect nuclear test explosions.

The force of the explosion measured between 300 and 500 kilotons, equivalent to a modern nuclear bomb, according to Bill Cooke, head of the Meteoroid Environment Office at NASA's Marshall Space Flight Center in Huntsville, Ala.

“When you hear about injuries, those are undoubtedly due to the events of the shock striking the city and causing walls to collapse and glass to fly, not due to fragments striking the ground,” Cooke said.

Scientists believe the object originated from the asteroid belt, a vast collection of debris orbiting between Mars and Jupiter that consists of leftover bits from the formation of the solar system. The asteroid probably traveled for a year before it burst into the atmosphere Friday. As yet, no fragments have been recovered, but experts believe the asteroid was rocky in nature, and not formed of dense iron and nickel...

[Verginius Rufus]

Most asteroids are in the asteroid belt, but not all of them--the ones which aren't are the ones we have to worry about.

It looks like there is a continuous range of sizes from very small meteors to the largest asteroids, and where we draw the line between "meteors" and "asteroids" is a matter of semantics. We can say that a meteor is an object up to a certain size and anything larger than that is an asteroid. They are all objects in space subject to the law of gravity.

[PapaBear3625]

If we had an even half-###’ed space program the last 20 years, by now we’d have the capability to spot from multiple locations, and the ability to hit something while it’s far enough away to be effective. It doesn’t actually take all that much to deflect one of these things “sufficiently” if it’s a couple weeks or more out.

We don't even need to "deflect" it. We just need something that will hit it hard enough to break it up, or at least crack it enough that it breaks up higher in the atmosphere. And the impact just needs to be between a few hundred to a thousand miles up.

Like you said, a bunch of smaller chunks will just burn up in the upper atmosphere, which is what we want to happen. The objective is to have it expend its energy heating up the upper edges of the atmosphere instead of doing damage to the ground. The higher up we break it up, the wider the spread of the chunks, and the more diffuse the effects.

[Eye of Unk]

I just woke up from a dream where I was at a resort and was looking out at a tall hill nearby and suddenly watched it start flying apart, rocks and trees blowing away from it and falling far away.

Maybe we will see a LOT of this in the near future, suppose we have this occurring every day or more often globally?

And lets just assume NASA or some other agency knew ahead of time and refused to make it public, or on a more serious note monitors private stargazers who also have seen an oncoming object but when they try to announce it they are silenced instead.

I have a feeling these objects were seen, plotted and even their strike area plotted, but nobody will announce the news.

[John Valentine]

When the rock hits the ground its a meteorite And when this "asteroid" hit Earth's atmosphere, it became, by definition, a meteor, NASA goofusses notwithstanding.

[Verginius Rufus]

Bill Cooke is quoted saying that telescopes can't see things in the daytime. Anyone who has a telescope knows you can use it in the daytime to look at a tree or a building or anything else, even the moon if it is up. The inventor of the telescope, Hans Lippershey, first used it in the daytime--it wasn't until Galileo heard of the invention and used it to look at the night sky that someone used a telescope at night.

Of course it is true that you can't detect a tiny asteroid in the daytime in a telescope.

[Vince Ferrer]

If they are of the same mass and composition, yes. Comets are typically less dense and mostly ice though, which will burn up faster in the atmosphere. But if a comet is rocky enough, then it will do more damage due to its higher speed.

[Verginius Rufus]

...There ain't a damned thing we can do...

Except to blame Bush.

[John Valentine]

...blame Bush?

Wait a minute here, I thought meteors were caused by global warming...

Oh yeah, I get it... it's ALL Bush's fault.

[Grandma Conservative]

But isn’t speed even more important than mass when it comes to energy: E = 1/2 mv^2 ?

[ilovesarah2012]

Wouldn’t it be easier to drop a bomb?

[PapaBear3625]

I just woke up and had yet another sci-fi recall, this book was about what happened when a super dense material hit earth, it was only the size of a baseball but weighed thousands of tons, it actually penetrated through the earth completely yet its exit was similar to a bullet exit and basically created a giant volcano.

Something with enough kinetic energy to pass through the Earth would likely generate enough shock waves with its passage to set off every volcano and earthquake fault on Earth. The effects would not be localized to the entry and exit points.

[444Flyer]

...Yes, it exploded during descent, but it wasn’t disintegrated or vaporized completely. Parts of this mini-asteroid became meteorites.

Would be interesting to try to count the number of 'booms' heard on those videos. I was wondering why it sounded like numerous explosions, but thought it might be an echo of some type.

[444Flyer]

The LORD’s wake up calls/warnings to a fallen world?

And we're about a month out from B.O.’s visit to Zion.

[Pikachu_Dad]

Yep, your missing something.

The moon, while rotating, always keeps one side facing the earth. So the earth protects that side of the moon from a lot of hits.

[Vince Ferrer]

But isn’t speed even more important than mass when it comes to energy: E = 1/2 mv^2 ?

Yes, but the atmosphere plays a part as well. If the material burns up in the atmosphere easier, then less of it will survive to reach the ground. Astronomers feel that an ice comet would burn up more than an iron core comet before it landed.

If you are thinking of the moment when it hits the earth, then it doesn't matter if the object is iron or ice, if they are equivalent mass, then the higher speed object will have much more kinetic energy hitting the Earth.

[Dust in the Wind]

Well there is the answer to the cause of global warming. Since energy is not lost but only converted. What will be the ensuing rise in earths temperature caused by all these bolids burning in our atmosphere? Did the one in Russia cause enough radiant heat to make the sandal wearing man not even notice the ice he was standing on. Inquiring minds want to know.../s

[doorgunner69]

That is a stunning picture. Can't recall seeing it before.

The fact that is is far more chewed up than the side facing earth is food for thought.

[doorgunner69]

I still puzzle over why such a huge chunk would explode if that dense. Moving that fast, the heating effect of the air drag would have very little dwell time. Burn off some outer layer stuff sure, but heat the whole thing hot enough?

No way. So, why do they explode like that?

[2ndDivisionVet]

IIRC there were no 747 aircraft involved in 9/11.

[MD Expat in PA]

This explains it pretty well.

Q & A: How could a meteor *explode*?