Stendec wrote:Apparently the folks in Chelyabinsk are quite fortunate that the meteor did not explode at an altitude lower than 12 - 18 miles (20 - 30 Kilometers). The explosive force of 500 kilotons is very much more powerful than the bombs which fell on Hiroshima (16 kilotons) and Nagasaki (21 kilotons) - - 31.25 times and 23.81 times more powerful, respectively. The bombs exploded less than half a mile above the ground (Hiroshima - detonation height about 1,968 feet; Nagasaki - detonation height about 1,539 feet). For comparison, look at the before and after pictures of Hiroshima and Nagasaki, and then do some mental extrapolation: http://en.wikipedia.org/wiki/Atomic_bom ... d_Nagasaki
:!:
Fortunately, a stony body of this mass can probably never make it much below where it actually did explode. It would take a much larger mass, which would both release more energy and do so lower. Double whammy. However, objects with larger mass are also rarer.
I suspect that thousands of people around Chelyabinsk have died from diseases related to the sloppy handling of radioactive materials, yet a few people in the hospital for glass cuts is what makes the big headlines. But that's the way things work, I guess.
Chris
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Chris L Peterson
Cloudbait Observatory https://www.cloudbait.com
Chris Peterson wrote:
I suspect that thousands of people around Chelyabinsk have died from diseases related to the sloppy handling of radioactive materials, yet a few people in the hospital for glass cuts is what makes the big headlines. But that's the way things work, I guess.
The meteor might have driven a lot of Chelyabinskians to drink, however.
Once when I was out jogging (back when I used to do that kind of thing) I ran straight into a moose, almost. Well, there was still about five meters between me and the moose, I guess. My first reaction was: I've run straight into the shooting of a wildlife TV show! Where's the impressive music?"
I guess the Russian guy also thought he was watching something from TV.
To be fair to the man from Russia, the casualties of the Chelyabinsk meteor were nowhere near as serious as the casualties of the Hindenburg disaster. So he had no obvious reason to cry out, "Oh the humanity!"
Ann wrote:
Once when I was out jogging (back when I used to do that kind of thing) I ran straight into a moose, almost. Well, there was still about five meters between me and the moose, I guess. My first reaction was: I've run straight into the shooting of a wildlife TV show! Where's the impressive music?"
<<The moose or Eurasian elk (Europe) (Alces alces) is the largest extant species in the deer family. Like any wild animal, moose are unpredictable and should be given a respectful amount of space. They are most likely to attack if annoyed or harassed, or if their "personal space" has been encroached upon. Moose that have been harassed may vent their anger on unwary victims, and often do not make distinctions between their tormentors and innocent passers-by. Moose are very limber animals with highly flexible joints and sharp, pointed hooves, and are capable of kicking with both front and back legs. Unlike other large, hooved mammals, such as horses, moose can kick in all directions including sideways. Therefore, there is no safe side from which to approach. However, moose often give warning signs prior to attacking, displaying their aggression by means of body language. The maintaining of eye contact is usually the first sign of aggression, while laid-back ears or a lowered head is a definite sign of agitation. If the hairs on the back of the moose's neck and shoulders (hackles) stand up, a charge is usually imminent.>>
flamencoprof wrote:May I suggest that "500 kilotons of energy " should read "energy equivalent to 500 kilotons of TNT"?
Exactly.
A unit of energy equal to 4.184 x 1012 joules is called a kiloton of TNT, and is formally abbreviated "kt" and almost always simply referenced as "kiloton" whenever the context makes it clear that energy is under discussion.
It is not generally necessary to qualify the unit with a reference to TNT.
Chris
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Chris L Peterson
Cloudbait Observatory https://www.cloudbait.com
Chris Peterson wrote:
A unit of energy equal to 4.184 x 1012 joules is called a kiloton of TNT, and is formally abbreviated "kt" and almost always simply referenced as "kiloton" whenever the context makes it clear that energy is under discussion.
It is not generally necessary to qualify the unit with a reference to TNT.
Chris Peterson wrote:
A unit of energy equal to 4.184 x 1012 joules is called a kiloton of TNT, and is formally abbreviated "kt" and almost always simply referenced as "kiloton" whenever the context makes it clear that energy is under discussion.
It is not generally necessary to qualify the unit with a reference to TNT.
"In those rare moments of total quiet with a dark sky, I again feel the awe that struck me as a child. The feeling is utterly overwhelming as my mind races out across the stars. I feel peaceful and serene."
MargaritaMc wrote:Does that mean that, on my 1500 kilo-calorie per day regime, I consume the energy equivalent of 1.5kg of TNT?
Yes, although I recommend consuming that energy in the form of caramel fudge ice cream as opposed to eating a brick of TNT.
(While 1.5 kg of TNT does seem very energetic, that is an illusion of the rate at which it releases that energy to heat- a few milliseconds. Stretch that same amount of energy over 24 hours- say 20 or 30 million times longer- and it's not so impressive. Indeed, it works out to a continuous power dissipation of a mere 72 watts, which is right around the average basal metabolic rate.)
Chris
*****************************************
Chris L Peterson
Cloudbait Observatory https://www.cloudbait.com
Was the Chelyabinsk Fireball Related to the Close Approach of Asteroid 2012 DA14?
Asteroid 2012 DA14 made a very close flyby of the Earth just over 16 hours after the Russian fireball event, passing within 27,700 km (17,200 miles) of the Earth's surface, but there is no connection whatever between these two events. First of all, the two objects approached the Earth from completely different directions, and had entirely different orbits about the Sun. A custom version of the JPL orbit display applet has been created to show the orbits of the Chelyabinsk impactor and 2012 DA14 at the same time:
A second reason we know the two asteroids approaching Earth on Feb. 15 were unrelated is their disparate compositions. Telescopic spectral data do not support any physical connection between asteroid 2012 DA14 and Chelyabinsk meteorites. Nicholas Moskovitz and Richard Binzel (MIT) report 2012 DA14 displays spectral colors which suggest a carbon dominated composition similar to CO or CV carbonaceous chondrite meteorites with abundant calcium- and aluminum-rich inclusions. On the other hand, meteorite fragments being recovered from the fireball event are reported as silicate-rich ordinary chondrites; a completely different and unrelated class of meteorites. About 80% of all meteorite falls are in the ordinary chondrite category.
Just trying to see if there was any link between Feb 17 APOD and Feb 23 APOD. Very neat to see the orbits displayed by the applet.
