Large meteor explosion detected

[Stu]

Interesting, and lucky where it exploded 

BBC News - US detects huge meteor explosion
http://www.bbc.co.uk/news/science-environment-47607696

 

[Unklewhale]

Thanks for this link - heard nothing about it from anywhere previously.

[Guest]

Thanks for this Stu. I read that it exploded approx fifteen miles high. Commercial airliners operate at about five miles I believe. But wondered how big the object was to cause the huge ? explosion. 

[Chris]

Thanks Stu, didn't have a clue about this. Lucky really, just imagine if this happened over somewhere populated! If I remember my undergrad physics rightly, Kinetic energy equals half the Mass times the speed squared, and 32,000 metres per second is a lot of speed to square! 

[Chris]

7 minutes ago, Grumpy Martian said:

Thanks for this Stu. I read that it exploded approx fifteen miles high. Commercial airliners operate at about five miles I believe. But wondered how big the object was to cause the huge ? explosion. 

Hi Martin, it said it was a few metres across. It's mainly the velocity component that creates the energy though.

[Stu]

6 minutes ago, Grumpy Martian said:

Thanks for this Stu. I read that it exploded approx fifteen miles high. Commercial airliners operate at about five miles I believe. But wondered how big the object was to cause the huge ? explosion. 

The article says it was several metres across. Travelling so fast though (32 km/s) which is why the energy is so high.

[Stu]

10 minutes ago, Lockie said:

Thanks Stu, didn't have a clue about this. Lucky really, just imagine if this happened over somewhere populated! If I remember my undergrad physics rightly, Kinetic energy equals half the Mass times the speed squared, and 32,000 metres per second is a lot of speed to square! 

Yep! It was certainly travelling!

[Craney]

I think this occurred on 18 December .....   probably taken time to corroborate data.

[Gfamily]

A satellite data specialist has identified the trail in Japanese Himawari satellite images

B&W images 

Colour images 

 

[Fozzie]

Nice Share @Stu.. Love that chart in the Beeb website recording the impacts, that is interesting..

1 hour ago, Lockie said:

 If I remember my undergrad physics rightly, Kinetic energy equals half the Mass times the speed squared

Spot on Chris, I was demonstrating this very thing to little Oliver this weekend while as I was emptying the dishwasher.. I stood up only to crack my head on an open cupboard door, that impact, while it didn't have a dizzying 32,000 m/s velocity, certainly had A LOT of Kinetic Energy..  felt like a good portion of the Chelyabinsk blast had gone of in my head.. I can only surmise that my mass made up for the lack of velocity in this instance..

Worst of it was, I'd left the door open in the first place!

[david_taurus83]

173 kilotons according to the article! ?

[Stu]

1 hour ago, Craney said:

I think this occurred on 18 December .....   probably taken time to corroborate data.

Yes, but I suspect because it occured over the sea in a fairly remote area it has only just been picked up by the media.

[Chris]

17 minutes ago, Fozzie said:

Nice Share @Stu.. Love that chart in the Beeb website recording the impacts, that is interesting..

Spot on Chris, I was demonstrating this very thing to little Oliver this weekend while as I was emptying the dishwasher.. I stood up only to crack my head on an open cupboard door, that impact, while it didn't have a dizzying 32,000 m/s velocity, certainly had A LOT of Kinetic Energy..  felt like a good portion of the Chelyabinsk blast had gone of in my head.. I can only surmise that my mass made up for the lack of velocity in this instance..

Worst of it was, I'd left the door open in the first place!

lol I did the very same thing not so long ago, knocked me to the ground and I had a mishaped head for a while. Luckily this physics lesson was just to myself ? 

[JamesF]

I just can't get my head around a speed of 32km/s.  That's, what, more than a couple of orders of magnitude faster than a commercial airliner?

James

[vlaiv]

4 minutes ago, JamesF said:

I just can't get my head around a speed of 32km/s.  That's, what, more than a couple of orders of magnitude faster than a commercial airliner?

James

1m/s = 3.6Kph

So this would be 115200 Kph or about x120 times airliner speed.

About 3.5h to reach the Moon at this speed, or about x93 speed of sound. Also, about 0.01067% of speed of light

 

[FaDG]

And about three times the speed of a Low Earth Orbit satellite. 

[maw lod qan]

With such a steep entry angle, it would have been devastation if it had been over a populated area and exploded just a bit lower.

We see a lot of concern about "the big rock" coming. Something like this over New York, or London is something I can't imagine.