Andrea Milani Comparetti Home Page
Posted on 06/30/2010 11:36:48 AM PDT by Dallas59
The object 2010 KH has been observed only by WISE and currently has a disgusting orbit: semimajor axis = 3.2 +- 3 AU. In fact, it might not even be a NEO. However, by using the available data, we have found Virtual impactors, including one in 2015, of course with a very low impact probability (the asteroid could be almost anywhere, thus we cannot exclude that it could be on top of us at some time in the near future).
Now this situation is very unpleasant. This object possibly does not even exist as a NEO, on the other hand the nominal solution is a NEO with absolute magnitude 18.2. Our way to handle this would be to proclaim that it has not been discovered, and refuse to give credit to WISE and to NASA for such a terrible job. However, as you well know, this kind of decision is not in our hands.
Our job is to report objects which might be impacting the Earth. It is not part of our style to adopt scare tactics to push astronomers to observe asteroids with Virtual Impactors; however, with very simple arithmetics, it can be deduced from our risk page that in case this asteroid was to impact the Earth in 2015, the impact energy is estimated at 8,000 megatons.
(Excerpt) Read more at tech.groups.yahoo.com ...
Hope this is appropriate for our ping list.
“Well, it’s useless to stop smoking and drinking now.”
Imagine Obama running on this theme in 2012: “You may as well re-elect me since we’ll all be dead in a few years anyway.”
Thanks for the ping.
4 later
oh ... my ..... God.... this is hugh and very series!!!
“8000 megatons is nothing to worry about. It’s a very quick way to die.”
Only if you’re relatively close, or on a coast that gets hit by a tsunami. On the grand scale of things, 8,000 MT isn’t so bad. The Chixclub (dinosaur killer) impact was 100,000,000 megatons.
If you’re over 100 mi. away you’ll escape without a scratch if it’s a land strike. At 62 mi. (100 km) here are the results from the U of A impact calculator:
Your Inputs:
Distance from Impact: 100.00 km ( = 62.10 miles )
Projectile diameter: 476.00 meters ( = 1560.00 feet )
Projectile Density: 3000 kg/m3
Impact Velocity: 20.00 km per second ( = 12.40 miles per second )
Impact Angle: 60 degrees
Target Density: 2500 kg/m3
Target Type: Sedimentary Rock
Energy:
Energy before atmospheric entry: 3.39 x 1019 Joules = 8.09 x 103 MegaTons TNT
The average interval between impacts of this size somewhere on Earth during the last 4 billion years is 1.3 x 105years
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 56600 meters = 186000 ft
The projectile reaches the ground in a broken condition. The mass of projectile strikes the surface at velocity 19.7 km/s = 12.2 miles/s
The impact energy is 3.29 x 1019 Joules = 7.87 x 10^3 MegaTons.
The broken projectile fragments strike the ground in an ellipse of dimension 0.767 km by 0.664 km
Crater Dimensions:
Crater shape is normal in spite of atmospheric crushing; fragments are not significantly dispersed.
Transient Crater Diameter: 6.77 km ( = 4.21 miles )
Transient Crater Depth: 2.39 km ( = 1.49 miles )
Final Crater Diameter: 8.73 km ( = 5.42 miles )
Final Crater Depth: 568 meters ( = 1860 feet )
The crater formed is a complex crater.
The volume of the target melted or vaporized is 0.254 km3 = 0.0609 miles3
Roughly half the melt remains in the crater, where its average thickness is 7.05 meters ( = 23.1 feet ).
Thermal Radiation:
Time for maximum radiation: 325 milliseconds after impact
Visible fireball radius: 5.63 km ( = 3.49 miles )
The fireball appears 12.8 times larger than the sun
Thermal Exposure: 1.33 x 10^6 Joules/m2
Duration of Irradiation: 1.39 minutes
Radiant flux (relative to the sun): 15.9 (Flux from a burner on full at a distance of 10 cm)
Effects of Thermal Radiation:
Much of the body suffers second degree burns
Deciduous trees ignite
Seismic Effects:
The major seismic shaking will arrive approximately 20 seconds after impact.
Richter Scale Magnitude: 7.2
Mercalli Scale Intensity at a distance of 100 km:
VI. Felt by all, many frightened. Some heavy furniture moved; a few instances of fallen plaster. Damage slight.
VII. Damage negligible in buildings of good design and construction; slight to moderate in well-built ordinary structures; considerable damage in poorly built or badly designed structures; some chimneys broken.
Ejecta:
The ejecta will arrive approximately 2.4 minutes after the impact.
At your position there is a fine dusting of ejecta with occasional larger fragments
Average Ejecta Thickness: 1.88 cm ( = 0.739 inches )
Mean Fragment Diameter: 5.49 cm ( = 2.16 inches )
Air Blast:
The air blast will arrive approximately 5.05 minutes after impact.
Peak Overpressure: 26700 Pa = 0.267 bars = 3.79 psi
Max wind velocity: 56.7 m/s = 127 mph
Sound Intensity: 89 dB (Loud as heavy traffic)
Damage Description:
Interior partitions of wood frame buildings will be blown down. Roof will be severely damaged.
Glass windows will shatter.
About 30 percent of trees blown down; remainder have some branches and leaves blown off.
I guess the model is now hosted in the UK, it’s pretty fun to play around with:
http://impact.ese.ic.ac.uk/ImpactEffects/
I doubt you want to be a lot closer than 62 miles... ;-)
8000 megatons? Could this be Al Gore cruising for chicks?
Is a disgusting orbit like an eccentric orbit, but grosser?
Maybe it will plug the damn hole.
Just for fun, ran the same calculation for an offshore strike 100 km off Southern California. All the effects were greatly diminished except for the fireball (same as above), and:
Tsunami Wave:
The impact-generated tsunami wave arrives approximately 10.8 minutes after impact.
Tsunami wave amplitude is between: 5.7 meters ( = 18.6 feet) and 81.6 meters ( = 268.0 feet).
My guess is the wave would tend towards the upper end of that range... ;-)
“Would it help to run around screaming? I bet not.”
Putting a bag over your head may make you feel better.
Here's a cool interactive orbit diagram for 2010 KH: JPL Small-Body Database Browser (2010 KH)
Once you've seen that, it's pretty hard to get worked up by fearmongering stories of a near miss from this asteroid.
Not the Earth! That's where I keep my stuff!
I wondered why the 7-11 was out of milk and toilet paper this morning.
A very descriptive phrase. Anyone know who originated it?
I believe it's a French term, normally used when the German's begin crossing the border.
After 4 years of civil war it might even be a relief.
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