There was no chance this would hit the Earth

[pscot]

http://www.youtube.com/watch?v=LCN77UZ2RUo

Asteroid 2011 MD flew past Earth on Monday, June 27th. At closest approach the ~10-meter space rock was only 12,000 kilometers (7,500 miles) above the planet's surface. NASA analysts said there was no chance it would strike Earth, and indeed it didn't

[RUMMYisFROSTED]

1. The scary part isn't that it might've hit the Earth (I believe in physics).

The scary part is that it, iIrc, was only discovered a few days ago.

[Occulus]

7. That would be the correct lesson to learn from this, I think

We aren't looking at enough of the sky yet- and pardon me, sir, but it's a big-ass sky.

[damntexdem]

16. Fairly small, so hard to detect.

That is, unless were to hit a city.

[MineralMan]

9. It sure could have. The next one that size just might.

It happens. I'm not sure what kind of impact an object 10 meters or so in size would have. Given the planet's water coverage, though, there's a good chance it would land in an ocean, and an object that size wouldn't do too much in that case.

[RUMMYisFROSTED]

24. Of course it could have. If it's trajectory was completely different.

:think:




"The next one"= pure imagination

[Cal33]

19. Unless it hit a populated area, an 11-yard-in-diameter rock from space

probably wouldn't have done much damage to earth.

[RUMMYisFROSTED]

23. Probably.

[MineralMan]

2. I wonder how much its orbit changed during the passage.

Which way will it go now? What is its orbital period?

[snooper2]

3. what size would it have been at impact after burning through the atmosphere?

Sure there's a writeup somewhere on that...

Starts size of a bus, ends up size of a fridge?

[Ready4Change]

8. I think I read it would have broken up.

I think it measured about 25 meters, and was mixed stony composition. They estimated it would have broken apart and burnt up?

Now, an iron rich one that size could ruin your morning.

[Occulus]

10. None

It was small enough to have completely burned up had it "hit". No effect on the ground, given its size.

I don't know if a different composition would have had any effect, but I kind of doubt it.

[Cal33]

21. I think a lot would depend on the angle from which the rock hits the earth. If the slant

is large, the rock would go through a lot more of air, and the chances of its burning
up completely are good. If the direction is vertical, the rock would go through the
least amount of air. It would retain much of its size.

[Deep13]

4. I'll have to look on the amatuer astronomy website...

...to see if anyone got photos.

[MineralMan]

6. That video is pretty good, actually.

Very interesting.

[Deep13]

12. Wow, that think is really cruising. nt

[Ilsa]

5. I wonder how much of it would burn up in the atmosphere and how

much would be left behind. It would probably hit an ocean.

[Occulus]

11. All and none, respectively.

Too small to be any threat on the ground.

[MineralMan]

13. Here's an analysis of a 10 meter solid rock asteroid impact.

I entered average figures for things like speed and angle. Looks like it would break up and not directly impact:


Earth Impact Effects Program

Robert Marcus, H. Jay Melosh, and Gareth Collins

Please note: the results below are estimates based on current (limited) understanding of the impact process and come with large uncertainties; they should be used with caution, particularly in the case of peculiar input parameters. All values are given to three significant figures but this does not reflect the precision of the estimate. For more information about the uncertainty associated with our calculations and a full discussion of this program, please refer to this article

Your Inputs:

Distance from Impact: 5.00 km ( = 3.11 miles )
Projectile diameter: 10.00 meters ( = 32.80 feet )
Projectile Density: 3000 kg/m3
Impact Velocity: 17.00 km per second ( = 10.60 miles per second )
Impact Angle: 45 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock
Energy:

Energy before atmospheric entry: 2.27 x 1014 Joules = 0.54 x 10-1 MegaTons TNT
The average interval between impacts of this size somewhere on Earth is 11.7 years
Major Global Changes:

The Earth is not strongly disturbed by the impact and loses negligible mass.
The impact does not make a noticeable change in the tilt of Earth's axis (< 5 hundreths of a degree).
The impact does not shift the Earth's orbit noticeably.
Atmospheric Entry:

The projectile begins to breakup at an altitude of 54000 meters = 177000 ft
The projectile bursts into a cloud of fragments at an altitude of 30100 meters = 98600 ft
The residual velocity of the projectile fragments after the burst is 12.9 km/s = 8 miles/s
The energy of the airburst is 9.67 x 1013 Joules = 0.23 x 10-1 MegaTons.
No crater is formed, although large fragments may strike the surface.
Air Blast:

What does this mean?


The air blast will arrive approximately 1.54 minutes after impact.
Peak Overpressure: 10.8 Pa = 0.000108 bars = 0.00153 psi
Max wind velocity: 0.0254 m/s = 0.0569 mph
Sound Intensity: 21 dB (Easily Heard)

http://impact.ese.ic.ac.uk/ImpactEffects/

Cool site!

[Ilsa]

22. Thanks! I'm gonna send this link to Hubby, you'll lve digging into the numbers and physics! nt

[JHB]

14. For scale, the space shuttle usually goes to 200-240 miles up...

...and geosynchronous satellites (weather & communication sats) are at a little over 22,000 miles, so it passed in between those zones.

It altered the asteroid's orbit significantly, but "significant" is a relative thing here: its big compared to the usual minute tug from a more distant pass, but unless you're familiar with how much a "usual" change would be, seeing the new orbit compared to the old one wouldn't look very different (one mostly-circle versus a slightly different mostly-circle).

[DainBramaged]

15. I wondered why the plate in my head was vibrating......

:crazy:

[Tommy_Carcetti]

17. Thank you, Bruce Willis.

You gave your life so we could all live.

And now let's all play a sappy Aerosmith song where Aerosmith laments the fact of what they've become...

[KatyMan]

18. Or maybe send Aerosmith to do Willis' job

or they could go together...

[BeFree]

20. Did they hitch a ride?

If NASA was prepared they could have attached a probe to that baby and gotten a free ride.

Well, there is always the next one.

[Liberal_in_LA]

25. interesting