Large-ish Meteor Hits Earth... But No One Notices (discovery.com)

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Large-ish Meteor Hits Earth... But No One Notices (discovery.com)

Posted by yaelk on Tuesday February 23, 2016 @10:59AM from the we-lived-to-tell-the-tale dept.

According to data released by the Fireball and Bolide Reports page of NASA's Near Earth Object Program, a large meteor exploded far off the coast of Brazil on February 6, 2016. The meteor was the largest atmospheric impact recorded since the famous Chelyabinsk bolide that exploded over Russia in 2013. Although the Feb 6 meteor didn't cause any structural damage, the meteor unleashed an energy equivalent of 13,000 tons of TNT exploding instantaneously.

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Well I'll Be.... What's that? by bobbied · 2016-02-23 11:03 · Score: 3, Funny

Whoosh!

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1. Re:Well I'll Be.... What's that? by quenda · 2016-02-23 15:58 · Score: 5, Funny
  
  New data has traced the trajectory of the meteor, and it originated from the Klendathu region.
  They were probably aiming for Buenos Aires.
This reminds me of something from the Cold War by istartedi · 2016-02-23 11:07 · Score: 5, Interesting

Back in the 80s, I seem to recall wire services carrying reports of a "mushroom cloud" over the ocean. It was reported by commercial pilots, probably reliable witnesses not inclined to make up things for jokes.
Speculation was undersea volcano, unusual thunderstorm convection, and impact. I don't recall them following up on it, and I think it remained a mystery... let's see if I can track this down in a few minutes before hitting submit....
Oh wow, it was easier than I thought it would be. Here's the original story.
It was the 3rd google hit for "pilots spot mushroom cloud". Would that all my searches were that easy.

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1. Re:This reminds me of something from the Cold War by no1nose · 2016-02-23 11:22 · Score: 3, Insightful
  
  It is interesting seeing the food prices from 1985 on this newspaper page in contrast to today's prices. Also the mushroom cloud reporting is cool.
2. Re:This reminds me of something from the Cold War by Maritz · 2016-02-23 21:24 · Score: 3, Insightful
  
  Not that long ago, I was looking up how much energy is in a lion.
  Did they just go with mass of lion times speed of light squared? ;)
  
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Someone noticed by Nkwe · 2016-02-23 11:12 · Score: 4, Insightful

Someone noticed, or we would be reading about it here...
Re:If a meteor... by WhiplashII · 2016-02-23 11:47 · Score: 2

Well, first off, we only know about it after it hits - it is going 30km/s, after all. These are too small to detect all of them.
For an example of the effects: The Little Boy atomic bomb dropped on Hiroshima on August 6, 1945 exploded with an energy of about 15 kilotons of TNT. So this is a tiny bit smaller than that, with no radiation. Direct deaths from the Hiroshima bomb (ignoring radiation deaths), about 80,000 out of 350,000 population. About 70% of the city's buildings were destroyed, and another 7% severely damaged.
So, to translate that to a direct hit on New York: about 1.8 million dead, all of downtown gone. If you find that hard to believe, consider the effects of 2 buildings collapsing on 9/11 - it destroyed a much larger footprint than just that of the building, and did a very complete job of destruction. We just do not build to withstand asteroids, just don't let them hit you...

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60% of the earth's surface is water... by rahvin112 · 2016-02-23 12:03 · Score: 2

When the planet's surface is 60% water the meteors are going to hit water 60% of the time. As a practical point of view most of the planet is devoid of human life when you take into account the areas like Siberia, the deserts and all the water, that the odds of an meteor hitting a populated area is staggeringly unlikely.
1. Re:60% of the earth's surface is water... by indi0144 · 2016-02-23 12:23 · Score: 2
  
  I'm pretty sure if the meteor were to crash in US you'd have systems and radars to at least track it for a bit, and know where it landed. You might even have StA missiles capable of locking in to the heat signature and exploding it (are they fast enough?). Not that I know if thats a good idea honestly but the technology should be there, right? This for your scenario of a rock like this hitting a city like NY where it makes sense to invest in it.
2. Re:60% of the earth's surface is water... by rahvin112 · 2016-02-23 13:17 · Score: 3, Informative
  
  The meteor would need to be at least the size of a fighter jet to be trackable. Beyond a certain size it won't even register on the radar because if radar tracked everything down to the size of small finch it would be overwhelmed by positive signals. A large meteor would almost certainly hit the tracking radar but the objects are moving so fast that by the time they notified anyone it would be over. But most meteors are of the size that they won't even register. The main point of my post is that most meteors don't hit near populated areas, as a percentage of the earth surface the entire USA doesn't even register beyond a single digit percentage making a rare event even rarer.
3. Re:60% of the earth's surface is water... by afidel · 2016-02-23 13:39 · Score: 3, Informative
  
  According to this article 2.7% of the land area is urban, that means ~1% of the total earths surface is urban land. If strikes are completely random then there should be a 1% chance that any given hit is in an urban area. Now I don't believe hits are completely random since the solar system is planer so areas nearer the equator probably have a higher percentage chance, but that may be balanced by more cities being near the equator (there are almost no large cities between 60 degrees north and 90 degrees and in the southern hemisphere it's even more striking with no large cities between 45 degrees south and 90 degrees)
  
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4. Re:60% of the earth's surface is water... by tnk1 · 2016-02-23 13:58 · Score: 4, Insightful
  
  Yes, this was incidentally why ballistic missiles launched from subs off the coast of the US were a huge concern. By the time you knew they were coming, you had about ten minutes or less to react. And there wasn't really anything short of other nuclear missiles that could shoot down an ballistic missile until recently, and nothing that could probably be activated on that sort of a notice even now.
  A meteor would probably come in as fast as a ballistic missile, and we wouldn't even have the advantage of knowing where the launch sites are and monitoring them.
  The big advantage over ICBMs is that they generally come from farther away and so there is more time to see them coming, but that assumes that you get lucky and find it before it enters the atmosphere. If you didn't see it coming, there's going to be zero chance of tracking it long enough to do anything about it, if you even saw it coming. At that point, even if you hit it with something, unless you atomized it the debris are going to impact and do a similar amount of damage.
5. Re:60% of the earth's surface is water... by JoeMerchant · 2016-02-23 15:14 · Score: 2
  
  the solar system is planer so areas nearer the equator probably have a higher percentage chance,
  True.
  
  but that may be balanced by more cities being near the equator
  False.
  
  (there are almost no large cities between 60 degrees north and 90 degrees and in the southern hemisphere it's even more striking with no large cities between 45 degrees south and 90 degrees)
  True - for a final score of 66.7%.
6. Re:60% of the earth's surface is water... by hackertourist · 2016-02-23 22:48 · Score: 2
  
  Radar primarily distinguishes by speed, not size. Objects below a speed threshold are ignored (*). Radar systems usually don't know much about the target's size, all they have is the strength of the return signal which depends on the radar cross section (i.e. reflectivity) of the target. The same object can have hugely different RCS, depending on the angle at which you're looking at the object.
  *: this was a big problem in the development of the AEW radar system for the Hawker Siddeley Nimrod: the RAF had specified a speed threshold of something like 100 km/h to catch slow-flying helicopters, but the system ended up detecting cars on motorways at that speed, in large enough numbers to overwhelm the tracking software.
7. Re:60% of the earth's surface is water... by dcw3 · 2016-02-23 23:26 · Score: 2
  
  From Wikipedia: some modern systems use shorter wavelengths (a few centimeters or less) that can image objects as small as a loaf of bread.
  And no, they would not be "overwhelmed by positive signals" either.
  
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8. Re:60% of the earth's surface is water... by Muad'Dave · 2016-02-24 03:32 · Score: 2
  
  > When the planet's surface is 60% water the meteors are going to hit water 60% of the time.
  Not exactly true. There seems to be a relationship between the fall rate and latitude.
  Also, the northern hemisphere has proportionally more land than the southern hemisphere (68% vs 32%), you'd expect about twice as many NH impacts on land than in the SH.
  
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Re:If a meteor... by tomhath · 2016-02-23 12:53 · Score: 2

The Chelyabinsk meteor was over 30 times more powerful than this one, and it did hit directly over a big city. But nobody was killed. It takes a much, much bigger rock to make it through the atmosphere.
Re:Hits earth? Not. by fisted · 2016-02-23 13:37 · Score: 2

Yes it is. Why would only solids and liquids qualify as Earth? And if the atmosphere is not part of Earth, then part of what is it?

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Nobody was looking by Anonymous Coward · 2016-02-23 18:54 · Score: 2, Informative

Since the Spanish Meteor Network started to work full steam, each month or so there have been reports in the news of large fireballs brigtening the night sky over the Iberian peninsula. And every few years about really big superbolide ones.
Even when every station is able to detect them only up to 500km away at best. the network reports 500 bolides every year, the lastest one this same week
The sky is falling, but nobody is looking.