Closest Ever Asteroid Passage Revealed

tricaric writes "Another asteroid passed, last March 31st, close to the Earth. This time it was only about 2 Earth radii from the Earth. The observation have been published only a few days ago, because 'Although the observed arc is only 44 minutes, the orbit is quite determinate and, given the exceptional nature of this close approach, the object is now receiving a designation.' Check out the ORSA animation!"

You know...

[Eneff]

I think I liked it better when I was blissfully ignorant of our impending doom.

Re:You know...

[NanoGator]

"I think I liked it better when I was blissfully ignorant of our impending doom."

Take comfort in knowing that your individual life is far more likely to end than the rest of the world's. I mean, 6 billion people aren't likely to suddenly die of an anyeurism.

Re:You know...

[isorox]

But the fun now isn't in shouting "WE'RE ALL DOOMED, THE END IS NIGH!!", but it's guessing the cause of our end. Asteroids, Aliens, Super Volcanos, Landsliding islands, Runaway Computer Viruses, Bad Holywood Movies, Global Warming, POTUS, run over by a bus, or whatever else tickles your fancy.

Re:You know...

[gujo-odori]

It will be bad Hollywood movies.

If you don't believe me, try to find a copy of "The Guns of El Chupacabra." "Gigli" seems like an Academy Award winner in comparison.

I could only stand it for about half an hour, and that even though the executive producer is a friend of mine and gave me a numbered promotional copy. Some of the music is actually pretty good, but they should have just recorded the bands and fired everyone else.

Re:You know...

[Eneff]

I'm really creeped out now.

This was supposed to be funny.

It was tiny...

[Selfbain]

If you read the article you can see that the asteroid was extremely small and would have broken up in the atmosphere.

Re:It was tiny...

[NaturePhotog]

If you read the article...
You're new here, aren't you? :-)

Re:It was tiny...

[snake_dad]

Yeah... but we need controversy, cover-up stories, sensationalism, doomsaying.. 't is The Internet Way!

Re:It was tiny...

[cephyn]

yeah but imagine if i was in plane and it hit me. DOOMED!

Re:It was tiny...

[OneOver137]

Yeah, but it would've made many satellite operators nervous to not have a good orbit determination. A collision in geo makes a mess and takes away much of that real estate for quite some time. Orbital traffic management for both known and 'alien' bodies such as this asteroid is a growing concern among those in the space operations business.

It was only 6m in diameter -- harmless

[jerde]

Wouldn't it be prudent to put in the story text that the object is estimated to be only 6 meters in diameter?

The article states that an object that size would burn up harmlessly in the atmosphere. I'm not sure if that's correct or not... a 6 meter hunk of material would probably rain at least SOME material down on the ground, but I don't know if it would make a crater.

The point is that we didn't just narrowly escape certain doom... it was a small rock.

- Peter

Re:It was only 6m in diameter -- harmless

[Carnildo]

A six-meter rock, if it doesn't break up in the atmosphere, will make a respectable crater -- maybe even knock down a few buildings. If it does break up, the fragments won't be big enough to leave craters, but can still hit hard enough to damage buildings or kill people.

Re:It was only 6m in diameter -- harmless

[WhatAmIDoingHere]

A few buildings... even if it managed to miss the ocean. And the large amount of land that isn't very populated.

Re:It was only 6m in diameter -- harmless

[hankwang]

A six-meter rock, if it doesn't break up in the atmosphere, will make a respectable crater -- maybe even knock down a few buildings.

I'm not sure what the relative velocity of the object compared to the earth's was, but if we estimate 20 km/s and a mass of 300 tons, then the kinetic energy of this object is about 6e13 J. That is about 15 kilotons of TNT worth of kinetic energy that you have to get rid of during the 1-2 seconds it takes to cross the atmosphere. The Hiroshima bomb was about 20 kilotons. I do

Re:It was only 6m in diameter -- harmless

[John Hasler]

If it's a cabonaceous chondrite (the most common type) it would almost certainly burn up and/or explode high in the atmosphere with little material reaching the surface. If its solid nickle iron it might very well reach the surface intact and make quite a hole.

Re:

[account_deleted]

Comment removed based on user account deletion

Re:It was only 6m in diameter -- harmless

[richie2000]

It's roughly two really small cars or one biggun. A Volvo 240 (the new yardstick for measuring asteroids, since I happen to have one handy) is just over 5 meters long. So if it helps, think of it as a large Volvo hurtling towards us from outer space at thousands of kilometers per hour (I'll save the detailed kph comparisons for later, but a standard Volvo 240 normally tops out at between 160 and 210kph depending on the engine).

Calculating how many Volvos there are in one Rhode Island is left as an exercise for the reader.

Re:It was only 6m in diameter -- harmless

[at_18]

Orbital velocities are usually of some tens of kilometers per second, which easily makes for hundreds of thousands mph. But such a small object would be slowed down by the atmosphere, and by the time it would hit the ground (assuming it would arrive intact at all) it wouldn't be much faster than terminal velocity - say 200 or 300 mph. Even on a populated area, it would do relatively little damage.

Re:It was only 6m in diameter -- harmless

[gstoddart]

So if it helps, think of it as a large Volvo hurtling towards us from outer space at thousands of kilometers per hour

as the driver either talks on a cell phone, applies make-up, or tries to use their laptop.

Spoon!

[Elwood P Dowd]

Another asteroid passed, last March 31st, close to the Earth. This time it was only about 2 Earth radii from the Earth.

Earth! That's where I keep all my stuff!

Re:Spoon!

[DaveS002]

Wow, I was gonna vacation there this year! Maybe not.....

Wasn't there one back in the 80's

[Trikenstein]

That missed the earth by 6 hrs? And IIRC it was a dino killer

I can't remember if it passed our orbit 6 hrs before we would have reached that point, or 6 hrs after we passed that point.

This one's a whole lot closer..

[dreamer-of-rules]

According to Earth Speeds [enchantedlearning.com], the Earth goes around the Sun at approximately 18.5 miles/sec, or 30 km/sec. In six hours the Earth will move 400,000 miles or 650,000 km around the sun. The radius of the Earth is roughly 4,000 miles or 6,500 km. So in six hours the Earth moves about 100 times its radius.

Basically, this latest asteroid is a lot closer.

Re:This one's a whole lot closer..

[Trikenstein]

This [astronomycafe.net] *may* be the event that I'm trying to remember.
Although I seem to remember it as being earlier in the decade and a larger asteroid.

My point is that the one on March 31st was closer, it was pretty small, the one I remember was much much larger, and it wasn't spotted until days after it passed behind us.

Re:This one's a whole lot closer..

[humuhumunukunukuapu']

"So in six hours the Earth moves about 100 times its radius"

if we had just left 7.2 minutes earlier we could have gotten it's autograph!

Personally I think this behaviour is irresponsible

[aminorex]

The original observations posted to the Harvard project site were pulled. I'm guessing they feared
controversies such as have occurred in the recent past when estimates were revised to preclude impact.
I think hiding the data is irresponsible in all cases, and it makes me distrust astronomers across the board.

Misleading Headline

[barakn]

"Closest Ever Asteroid Passage Revealed?"

check out the 1972 daylight fireball [agleia.de]. It came so close it actually skipped off the atmosphere. There are plenty of other close encounters in the literature that came well before this.

Tunguska event

[FooAtWFU]

Well, the Tunguska event [wikipedia.org] of 1908 is a case of one of these actually hitting the planet- though I guess it doesn't qualify as a "passage".

Re:Misleading Headline

[Muad'Dave]

As the article says, this is the closest approach to be detected astrometrically. They mention the 1972 fireball as the closest "approach" since it flew through our atmosphere.

Re:Misleading Headline

[barakn]

What's your point? I was talking about the slashdot headline. In fact the entire /. story failed to mention the word "astrometrically." Just proving that once again slashdot editors and story submitters don't RTFA.

Re:Misleading Headline

[Begossi]

Right below the article there's small note explainning why it was a remarkable observation:

"is by far the closest ever observed astrometrically." The distinction is important, because the title of "closest ever observed" probably belongs to the well documented Great Daylight Fireball of 1972. On August 10th many witnesses, including a meteor expert, saw and photographed an object of about 2004 FU162's size fly through Earth's atmosphere, traveling from south to north along the Rocky Mountains of the U.S.

Heisenberg / Uncertainty Principle

[topher67]

So due to the Heisenberg / Uncertainty Principle [aip.org] it would have hit us if we had not measured its trajectory, right?

March 31st? So if it had hit us?

[tod_miller]

And hadn't been a small asteroid, then I could be dead now, and in heaven reading slashdot, and not know about it.

I think this is a bit of a non-story. So this is the closest observed asteroid that hasn't actually hit us

The funny thing is if this had hit us it wouldn't have made the news, unless it had hit someone famous, and only if they were doing something scandalous at the time.

The wierd electrical fires in Sicily [worldnetdaily.com] were more interesting.

Re:March 31st? So if it had hit us?

[the real darkskye]

Reminds me of the space.com [space.com] headline Space storm hits, Earth Survives! [space.com] during the solar activity last year.

Re:March 31st? So if it had hit us?

[slowhand]

[...in heaven reading slashdot...]
Has anyone checked if /. domain is registered there yet? Think of the opportunity...

Don't worry ..

[Peter_JS_Blue]

.. I read somewhere that our atmosphere will protect us from anything upto the size of a house. As this rock is about the size of my living room I don't think it would have dome much damage.

Maybe it would have been good if it did hit us

[kippy]

Consider what might happen if this particular rock did hit us. 6 meters isn't enough to wipe out a city and it's unlikely that it would have hit in a populated area. Assuming that it didn't kill or hurt anyone, it might have been a good thing if it hit the ground.

Why? Because a big, fat, headline making impact (or splash) would really catch everyone's attention. A miss just catches our (the nreds') interest for a bit. If people perceive that there is an actual threat, perhaps space exploration and planetary defense will be taken seriously for a change.

Re:Maybe it would have been good if it did hit us

[confused one]

but a 6m asteriod would have only produced a big flash and bang. No real damage.

Original poster right: Check out the animation!

[Larthallor]

My eyes kept getting wider and wider! Granted, I wasn't aware of the object's size when I saw it, but still!

In case you miss it, those little circles around Earth that you can't even read when the animation begins are the orbits of geosynchronous satellites, such that provide GPS, weather images, and satellite TV!

It's an animated GIF, btw.

That's no moon!

[BoogieChile]

It's a bloody rock, is what that is.

If you want to call that an asteroid, then this [http] is also an asteroid? This was a meteor that passed right through Earth's atmosphere in 1976, with a perehelion of 58,000 metres.

Although, I think the point here is that this is the closest observed astronomically. It's like seeing the meteor before it hits the atmosphere, I guess. Anyway, the astronomers are all in a tizzy over it, so that must be a good thing.