Giant asteroid to 'narrowly miss' Earth

reply to post by poet1b

Originally posted by poet1b

Glad to know they can detect asteroids of this size.

Helps me to sleep at night.

Sorry pal couldn`t resist the urge

It is VERY Close, Check out the Horizions calulatins on JPL labs site



Change the Parimeters to Minutes
Change theTime Span [change] : Start=2011-06-26, Stop=2011-07-28, Step=1 m

click Generate...
Now the results are closer then 0.005?
like 0.00012******* AU

The closest point within several minutes is shown here, CLick on "CLOSE APPROACH DATA",,,
Close approach data


Would love to be in a position to view,,,
Cheers

Could this be one of the rocks associated with elenin, Nibiru, or anything else?

I worry about THIS one.....www.deepastronomy.com...
It would be very bad if it struck earth.

Originally posted by TheComte
I hope a nice sized chunk falls on my lawn.

If I survive, I'll be rich.

Be nice it it was made up of a new element!

But 20m wide, it wouldn't survive the atmosphere.

Unless this new element was awesome! Then you would be richer!

Originally posted by leemachino
Misleading title. 20 meters is not giant. Not sure if I would even call it an asteroid. Maybe a large meteor.

I know what you mean. But apparently NASA is quite liberal with use of the term "asteroid". the asteroid called 2008 TC3 was only about 3 meters across when it impacted the Earth, roughly the size of a truck. Some little pebble-sized pieces hit the ground after it exploded in the air and mostly burned up. This is one of the "pebbles" that hit. Not much of a crater:

www.nasa.gov...
[atsimg]http://files.abovetopsecret.com/images/member/df52760fdd30.jpg[/atsimg]

Originally posted by fixer1967
Well this one was 50 meters and hit with force of 10 megatons so based on that 20 meters would work out to able 4 megatons.

No, it wouldn't (assuming similar composition/density).

You might want to re-do the math.

The proper comparison is the volume. (leading to a mass at a given density).

You didn't make the comparison based on volume, you made it based on diameter, therefore your calculation is way off, not even close.

And even using the volume or mass calculation isn't that accurate, though it would be a lot better. The smaller objects tend to burn up and/or explode so high in the atmosphere that the effective impact on the ground is zero megatons of TNT. I don't know if it would amount to a couple of pounds of TNT, when some pebbles leftover hit the ground, which is what happened with 2008 TC3 seen above. In fact if we applied your math to 2008 TC3, it would have the explosive power 40 times as powerful as the Hiroshima atomic bomb. Obviously it didn't, by the time it reached the ground it didn't do much at all as you can see.

As of 2011 the International Astronomical Union officially defines a meteoroid as "a solid object moving in interplanetary space, of a size considerably smaller than an asteroid and considerably larger than an atom".[1][2] Beech and Steel, writing in Quarterly Journal of the Royal Astronomical Society, proposed a new definition where a meteoroid is between 100 µm and 10 m across.[3]

en.wikipedia.org...

So this one (2011 MD) is a very small asteroid or big meteoroid

impact.ese.ic.ac.uk... nice link to calculate damage from asteroids
this one wouldn't do much of anything and one this size hits the Earth once every 75-100years or so

reply to post by zorgon


It's small enough for Majestic to lock on to it with a tractor beam and tow it to the
asteroid belt and park it there.

Originally posted by Eurisko2012
It's small enough for Majestic to lock on to it with a tractor beam and tow it to the
asteroid belt and park it there.

Well if you were riding on the rock... this is the view

Originally posted by Phage
Already posted.
www.abovetopsecret.com...

20 meters across is not a giant asteroid.

Perspective is everything,phage.


It sure seems pretty big if it is about to fall on my head.

Which it's not......

Originally posted by Arbitrageur

Originally posted by fixer1967
Well this one was 50 meters and hit with force of 10 megatons so based on that 20 meters would work out to able 4 megatons.

No, it wouldn't (assuming similar composition/density).

You might want to re-do the math.

Okay...

Originally posted by Ironclad
20meters... Thats 60 feet in Diamiter.... Something that size won't totally burn up in the atmosphere. It would make an awsome mini-nuke when it hit and a nice hole in the ground..lol

Here is some average data, based on a nickel iron meteorite of 20 meters dia entering at 45 degree angle at an average speed. I used distance from impact at 1 kilometer

Your Inputs:
Distance from Impact: 1000.00 meters ( = 3280.00 feet )
Projectile diameter: 20.00 meters ( = 65.60 feet )
Projectile Density: 8000 kg/m3 (nickel/iron)
Impact Velocity: 20.00 km per second ( = 12.40 miles per second )
Impact Angle: 45 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock

Energy:
Energy before atmospheric entry: 6.70 x 1015 Joules = 1.60 MegaTons TNT
The average interval between impacts of this size somewhere on Earth is 169.6 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 16600 meters = 54400 ft
The projectile bursts into a cloud of fragments at an altitude of 4780 meters = 15700 ft
The residual velocity of the projectile fragments after the burst is 8.08 km/s = 5.02 miles/s
The energy of the airburst is 5.61 x 1015 Joules = 1.34 x 100 MegaTons.
Large fragments strike the surface and may create a crater strewn field. A more careful treatment of atmospheric entry is required to accurately estimate the size-frequency distribution of meteoroid fragments and predict the number and size of craters formed.

Air Blast:
The air blast will arrive approximately 14.8 seconds after impact.
Peak Overpressure: 40100 Pa = 0.401 bars = 5.69 psi
Max wind velocity: 81.5 m/s = 182 mph
Sound Intensity: 92 dB (May cause ear pain)

Damage Description:
Multistory wall-bearing buildings will experience severe cracking and interior partitions will be blown down
Wood frame buildings will almost completely collapse.
Glass windows will shatter.
Up to 90 percent of trees blown down; remainder stripped of branches and leaves.

impact.ese.ic.ac.uk...

Not exactly a small rock

reply to post by zorgon


Great animation! I thought it was going to crash into Antarctica !
----------------
More food for thought.
- A small asteroid going very fast could do the same amount of damage as a large
asteroid going slow. --

I heard that on the Discovery Channel.

reply to post by zorgon


according to neo.jpl.nasa.gov... the relative velocity of 2011 MD is only 6.7 km/s much less than the 20km/s you are using in calculation. Also most asteroids/meteoroids are not metal (about 10% are Fe-Ni).


change those two parameters and the effects much much less


Your Inputs:

Distance from Impact: 1000.00 meters ( = 3280.00 feet )
Projectile diameter: 20.00 meters ( = 65.60 feet )
Projectile Density: 3000 kg/m3
Impact Velocity: 6.70 km per second ( = 4.16 miles per second )
Impact Angle: 45 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock
Energy:

Energy before atmospheric entry: 2.82 x 1014 Joules = 0.67 x 10-1 MegaTons TNT
The average interval between impacts of this size somewhere on Earth is 68.4 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 39100 meters = 128000 ft
The projectile bursts into a cloud of fragments at an altitude of 18000 meters = 59200 ft
The residual velocity of the projectile fragments after the burst is 3.69 km/s = 2.29 miles/s
The energy of the airburst is 1.97 x 1014 Joules = 0.47 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 54.7 seconds after impact.
Peak Overpressure: 75.6 Pa = 0.000756 bars = 0.0107 psi
Max wind velocity: 0.178 m/s = 0.399 mph
Sound Intensity: 38 dB (Easily Heard)

ZOMG ITS ELENIN!!!!!! EARTHQUAKES, VOLCANOS AND STORMS OH MY!!!!

Now im going to have blue beam all my paperclips, done a lizard mask and learn reticulian!!!!

Rmbr that Elenin broo-ha-ha?, where did all that go?, is that still trendy?, or are those whack jobs just biding there time?

Originally posted by Eurisko2012
Great animation! I thought it was going to crash into Antarctica !

Pretty neat course change, huh?



But hey trust NASA they tell us its a rock

Originally posted by Phage
Already posted.
www.abovetopsecret.com...

20 meters across is not a giant asteroid.

THANK ....YOU!......

Originally posted by Magnivea
I hope it hits the hell out of us. Only if it has the zombie virus on it, though. Man, I've been waiting years for that.

Yep me too

reply to post by GogoVicMorrow


Eh.. i had the wrong info. If it did an airburst it'd prob be around a megaton.. definitely not what I originally though it was.

Originally posted by snowen20

Originally posted by Phage
20 meters across is not a giant asteroid.

THANK ....YOU!......

No but it is a giant meteorite

Man that was close! I was really sweating it.