Starship Asterisk*

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:

http://neo.jpl.nasa.gov/orbits/2012da14.html

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.

MargaritaMc wrote:Does that mean that, on my 1500 kilo-calorie per day regime, I consume the energy equivalent of 1.5kg of TNT?

MargaritaMc wrote:

neufer wrote:
Dietary calorie or food calorie = 4.184 kilojoules = a gram of TNT = a nano unit of energy

A food calorie is a kilo-calorie, according to the bible (slimming world)

Does that mean that, on my 1500 kilo-calorie per day regime, I consume the energy equivalent of 1.5kg of TNT?

http://asterisk.apod.com/viewtopic.php? ... 05#p193992

neufer wrote:

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.

So why can't they list the calorie count of desserts in "energy units"

Dietary calorie or food calorie = 4.184 kilojoules = a gram of TNT = a nano unit of energy

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.

-is wrote:

flamencoprof wrote:May I suggest that "500 kilotons of energy " should read "energy equivalent to 500 kilotons of TNT"?

Exactly.

flamencoprof wrote:May I suggest that "500 kilotons of energy " should read "energy equivalent to 500 kilotons of TNT"?

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?"

http://en.wikipedia.org/wiki/Moose wrote:

---

<<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.>>

neufer wrote:

SJoe wrote:
http://www.youtube.com/watch?v=LoDcjs6q4c8

Russian Reaction To Meteorite

Click to play embedded YouTube video.

SJoe wrote:
http://www.youtube.com/watch?v=LoDcjs6q4c8

Russian Reaction To Meteorite

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.

  

  Click to view full size image

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
:!:

woodman wrote:so...a higher point of explosion would mean occurring in a less dense part of the atmosphere. I assumed it was all about atmospheric pressure. If it is also heat buildup, why wouldn't it still happen at the same point? A flatter trajectory is longer, but through thinner air, on average, so heat would build more slowly than on a steep descent - still confused! thanks.

aildoux wrote:
I've seen many videos of this meteor but this is the first actual still picture taken of it that I've seen. Could it be the only one yet?

• No... but it is definitely the best

http://translate.google.com/translate?sl=ru&tl=en&js=n&prev=_t&hl=en&ie=UTF-8&eotf=1&u=http%3A%2F%2Fmarateaman.livejournal.com%2F27910.html&act=url wrote:
Google Translation of Marat Ametvaleev ("marateaman") :

[list]The explosion of a meteorite in the sky over the Chelyabinsk.
Full photo report with comments.[/list]----------------------------------------------------------------

• Morning. Beginning.

The morning was frosty (About -17 C), windless and cloudless. And because the day before was a very warm day (the temperature was near zero) - the trees were covered with frost. I decided to go to the scene to photograph their favorite point close to home. Around 9:00 am, I was at the scene and began to make the first shots. Unusual and remarkable in the sky before the object was not. After making a few shots from different angles, I moved to a different camera angle. The camera is pointed in the direction of the rising sun (the sun appears to have remained a matter of minutes.)
----------------------------------------------------------------

• Flash.

Yes! The appearance of the object was a surprise! The camera was on a tripod and aimed almost at the side (pictured above), which appeared object. I leaned over to the camera to change the camera angle and make another shot the scene. At this point, peripheral vision, I saw a bright flash. At first it was small. Immediately turned the camera to the object, and at this time of the outbreak has reached its peak, and everything was bathed in bright light.
----------------------------------------------------------------

• Awareness.

The first thing I thought was not a meteorite, a nuclear bomb. Then he remembered about the media reports about a possible asteroid and its approach to the Earth. Then there was the idea of an airplane that crashed.
----------------------------------------------------------------

• Feelings.

In the first seconds quickened heartbeat and breathing, as well as shaking hands, which is likely to be the consequences of the shock of what he saw. When the flash was as bright as possible, I felt strong enough heat in the face (it lasted just a split second.)

At the time of bright light, I also felt a strong pain in the eyes of intolerable glare. No more physical sensations were not. Then, 2 minutes after the flash, there was a series of explosions - the sound was neraskatisty and clear and very powerful. The first explosion was very strong, but I felt only the cotton. No physical sensations and vibrations I felt as was far from concrete structures and roads. Immediately after a series of bombings over the pine forest, near a large number of birds rose up and flew in all directions. Heartbeat, breathing, and hand tremors only strengthened. Shock was even greater.
----------------------------------------------------------------

• Shooting.

As mentioned earlier, immediately after seeing the first outbreak, I turned the camera towards the subject and take a single picture. He was heavily overexposed, I frantically started trying to fix the exposure to capture neperesvechenny object. I do not remember exactly how I made ​​the frame with hot particles inside track. Everything was a blur, and occurred in a matter of seconds. Next, the actions I remember vaguely. I did everything "on automatic." Shock did not allow to concentrate to put the correct values ​​and choose a great camera angles. I remember that I dropped in the snow control from the camera to change the filter on the lens. Only after a series of blasts I came a little to himself, was able to set the correct exposure, choose camera angles and shoot a few panoramas with residual cloud of meteorite.

A few words about how to change the nature around. Feels like the sky was bluer and transparent. The sun had already risen, but its brightness was like no more morning sun, and the sun is at its zenith.
----------------------------------------------------------------

• P. S.

Already after I shot footage, and cloud almost dissipated, I collected all the techniques and some time just standing. Observe nature around them, and considered their experiences. First thoughts were of loved ones, it was very difficult to get through, because network was overloaded. These thoughts haunted, were not allowed to recognize the scale of the incident and its consequences. On the way home I thought about the ownership of something global and very important. Only when I got in touch with his family, was able to concentrate on what they saw. First news on the Internet is not given any clarity. I immediately set about processing the footage and prepare it for publication. During the day, began to receive various news and various assumptions. Depressive mood is injected into society.

Still, it is good that we live in the information age! You can quickly share their experiences, and get the big picture scene.>>

Chris Peterson wrote:

woodman wrote:Have the scientists estimated the angle of incidence of the meteor? Would a more perpendicular entry increase the meteor's explosive energy, or is that solely a factor of its mass?

The entry angle was approximately 20° from horizontal. Had it arrived at a steeper angle, it probably would have exploded higher, resulting in lower energy densities at the ground and therefore less damage. The total thermal and acoustic energy could have been higher or lower, depending on the dynamics of the breakup.

woodman wrote:Have the scientists estimated the angle of incidence of the meteor? Would a more perpendicular entry increase the meteor's explosive energy, or is that solely a factor of its mass?

woodman wrote:Have the scientists estimated the angle of incidence of the meteor? Would a more perpendicular entry increase the meteor's explosive energy, or is that solely a factor of its mass?