Some are more memorable:
Posted on 02/16/2013 11:40:13 AM PST by Ernest_at_the_Beach
Geez, I don't think so! Why would there be? The angle of the shock wave to the flight path just gets steeper as the Mach number increases. I believe at high Mach numbers, there are qualitatively new effects, but this is due to intensification of the shock front.
The double boom from the Space Shuttle was due to two separate shock waves orginating from the nose and the tail, I think.
Some are more memorable:
Now that's a REAL problem. Climate Change indeed.
I think he’s right about harmonics but not sure if those are audible.
Smaller fireballs are extremely common events, which often wouldn’t make any more than the local media previously.
It’s the “attention effect” once again.
But the Cuba fireball detonation is reported to have shaken windows, which is definitely not an everyday thing.
There’s going to be a documentary on this at 8PM Eastern tonight on the Science Channel (my cable’s guide hasn’t updated to show this yet.)
the shuttle is what i based it on but never though of the tail creating it's own sonic boom... guess yer right
What the heck was THAT?
That is what the Russian girl was saying on her cell phone,...see #21!
Why do they keep calling it a meteorite?
It is only a meteorite after it hits the ground.
Before that it is a meteor.
“These results come with ABSOLUTELY NO WARRANTY”
Their results are consistent with NASA’s 15/300kt/20 degree/20000m/sec scenario, except the over pressure, which was demonstrably greater, about 5X greater.
I don’t think the calculator is including the sonic boom from the passage, just the explosion.
However, an article in Nature states the blast damage was from the explosion, not the sonic boom:
http://www.nature.com/news/russian-meteor-largest-in-a-century-1.12438
On further thought, I suspect that the overpressure was much higher than the calculator because the (simple) calculator may simply have the air blast effects be spherical, when in reality they were focused along the path.
The paper explaining the calculator is quite technical and can be found here:
http://impact.ese.ic.ac.uk/ImpactEffects/effects.pdf
great satellite pics of meteor
The term “meteor” is a piece of arcana referring to any atmospheric phenomenon, such as a cloud, or lightning. Meteors as we know them were not understood, and the association of found meteorites with the percieved “meteor” was controversial. So the term was analogous to “UFO”, in referring to an unknown phenomenon in general terms.
“Meteor” as a general term fell out of use and is now reserved for the particular phenomenon that we understand very well, for the most part. However its is still phenomenological, referring to the observed appearance, and not any cause or object associated with it.
Hence, we have “meteoroid” for a rock in space, and “meteorite” for whatever makes it to the ground, but what is it when it is seen producing the “meteor” that we see? A nice question, but a purely rhetorical one.
A meteoroid is a modestly-sized rock (up to boulder size) anywhere in the solar system, and the visual appearance upon entering the atmosphere is called a meteor.
I concede this is not particularly important information and I am just keeping the thread alive
The calculator notes, also state that the minimum velocity at impact is 11 km/sec (I’m buying it), but that the maximum velocity for a solar system object is 72 km/sec. Classically, the maximum velocity on impact with the earth for a solar system body is 44 km/sec = sqrt( 2*(mu_sun/R_earth_orbit + mu_earth/R_top_of_atmosphere))
The maximum orbital energy for an object to be graviationally bound to another body is 0. More than that and it has escape velocity. When the energy is 0, the velocity is:
v = sqrt( 2*mu/R)
For earth mu = 398600.4418 km^3/sec^2, R ~ 6491 km from center, = 11 km/sec
For the sun mu = 132712440018 km^3/sec^2 , R ~ 150,000,000 km from center, = 42.07 km/sec
The energy adds, regardless of path, so the resultant velocity is root of the sum of the squares, or about 44 km/sec
Spherical dissipation goes as 1/R^3, line source as 1/R^2, so you may be on to something.
Check your spelling.
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