Meteoroid explosion in Russia

[RGClark]

Extraordinary video that shows how often we are visited by visitors from the sky ...

An Asteroid's Parting Shot.
By Phil Plait
Posted Tuesday, Feb. 19, 2013, at 8:00 AM
http://www.slate.com/blogs/bad_astr...eroid_2012_da14_seen_in_time_lapse_video.html


Bob Clark

 

[Thunder Chicken]

More dash-cams!

http://www.guardian.co.uk/world/video/2013/feb/15/russian-roads-dash-cams-video

N.

Dash cams are far less ubiquitous in the U.S., they are mostly in police vehicles. I think in Russia they are more concerned with getting blamed for something that they didn't do; in the U.S. we are more concerned with being able to do stuff and not get caught :lol:

 

[Keatah]

For life's everyday moments there's Russian dashcams.
For everything else there's Mastercard.

Here in the US we don't want everything filmed. Makes it too hard to get away with stuff.

 

[Andy44]

The Asteroid was attacked by the atmosphere. that's what caused it to fragment and break apart.

What actually happened was that the meteoroid was struck by the Earth, which destroyed it utterly, annihilating the tiny civilization living on the rock. We'll never know those poor little people ever even existed!

 

[Keatah]

We were thinking over here what if some disturbance has happened (or is happening now) in the Oort Cloud?

 

[Thunder Chicken]

What actually happened was that the meteoroid was struck by the Earth, which destroyed it utterly, annihilating the tiny civiliazation living on the rock. We'll never know those poor little people ever even existed!

This reminds me of a time several years ago when I first started with Orbiter and was trying to set up scenarios and learning about elements. I somehow put my DG at orbital altitude relative to the Earth but stationary relative to the Sun.

I learned *really* quickly that a) I was prograde relative to the Earth and b) the Earth orbits the sun at something like 70,000 mph. I got run down by the Earth like Wile E. Coyote in a particularly vicious Roadrunner cartoon. I had about 8 seconds to moan "oh no..." :lol:

 

[Spaced]

"but in this video (at around 0:40) you can see the meteoroid "breaking apart", or something like that"

I thought it was the meteor breaking up when I first saw that vid. But on closer inspection it's clearly down to surface irregularities/scratches in the windscreen of the car.

 

[Scorpius]

A few more meteorite fragments were found, this time south from Chelyabinsk. Here is largest of them:

Also first fragment of the meteorite was delivered to Moscow for more detailed analysis on Friday, with results expected in a week.
http://en.ria.ru/science/20130222/179621800/Meteorite-Fragment-Brought-to-Moscow.html

 

[Ghostrider]

We were thinking over here what if some disturbance has happened (or is happening now) in the Oort Cloud?

You mean, as if millions of voices cried out in terror and were suddenly silenced?

 

[statickid]

looks kind of unchondrulally grey. Maybe its an old lunar rock that was blasted into solar orbit.

OR

Wouldn't it be interesting if a large molten blob of earth rock was hurled into space by something large, say, the impact in Ontario, and remained a NEO for millions of years, then re-impacted?

 

[Ghostrider]

Wouldn't it be interesting if a large molten blob of earth rock was hurled into space by something large, say, the impact in Ontario, and remained a NEO for millions of years, then re-impacted?

One hell of a "return to sender"...

 

[SiberianTiger]

What do Russian drivers typically do, when they see a 200 kt explosion heads-on?

 

[RGClark]

On this page it says the orbits "cross" at two locations, or more precisely, which
body is on the outside orbit changes twice per orbit:

La Sagra Observatory discovers very near-Earth asteroid 2012 DA14.
Posted By Jaime Nomen
2012/03/27 05:20 CDT
"The preliminary orbit shows that 2012 DA14 has a very Earth-Like orbit with a period of 366.24 days, just one more day than our terrestrial year. The orbit is nearly circular but just elliptical enough to jump inside and outside of the path of Earth two times per year. Because objects move faster when they are closer to the Sun, the relative motion is similar to some sports races: when the Earth is on the outer track, it is overtaken by 2012 DA14, but when the asteroid crosses Earth's orbit, Earth overtakes it and passes by. It is during the orbit crossings when the closest encounters occur, and when there is potential for a future impact."           
http://www.planetary.org/blogs/guest-blogs/3418.html

Does this mean there are two close approaches per orbit? It doesn't necessarily have to be, since where the two orbits "cross" does not mean the two bodies have to be there at the same time. On the other hand because they have similar orbits and therefore similar speeds, if they are close at one "crossing" point, they should be relatively close at the other.


Bob Clark

 

[Quick_Nick]

It would be like having a circular orbit around ISS height. (While the ISS has elliptical) So I imagine in some orbits, they "cross" (read overtake) twice, some only once, and many more orbits they are far apart. I don't know if we're just starting the crossing years or entering a "far" period though.
So although it goes in the path of Earth's orbit twice a year, Earth may well be on the other side of the Sun some years.

 

[Thunder Chicken]

It would be like having a circular orbit around ISS height. (While the ISS has elliptical) So I imagine in some orbits, they "cross" (read overtake) twice, some only once, and many more orbits they are far apart. I don't know if we're just starting the crossing years or entering a "far" period though.
So although it goes in the path of Earth's orbit twice a year, Earth may well be on the other side of the Sun some years.

In some parts of the orbit earth is gaining on 2012 DA14, some parts vice versa. But based on periods Earth and 2012 DA14 coincided this year; next year when Earth returns to the same point in the orbit, 2012 DA14 will be a day behind. The year after that it will be 2 days behind. So unless the orbit is heavily influenced by earth (?), we shouldn't need to worry about it for 365 years?

 

[Quick_Nick]

In some parts of the orbit earth is gaining on 2012 DA14, some parts vice versa. But based on periods Earth and 2012 DA14 coincided this year; next year when Earth returns to the same point in the orbit, 2012 DA14 will be a day behind. The year after that it will be 2 days behind. So unless the orbit is heavily influenced by earth (?), we shouldn't need to worry about it for 365 years?

I imagine you're right.
I didn't think too deeply into how much it would change each year, but you're right, it ought to be an entire 'day late' the next year. In the ~365 years til the next encounter, maybe we should focus on the other rocks speeding through our neighborhood.

 

[Thunder Chicken]

I imagine you're right.
I didn't think too deeply into how much it would change each year, but you're right, it ought to be an entire 'day late' the next year. In the ~365 years til the next encounter, maybe we should focus on the other rocks speeding through our neighborhood.

The only wrinkle is that it remains relatively close to Earth for a while, so I imagine it entrains in some fashion.

1 day = 1/365th of an orbit

Orbital circumference = 2*pi*(98,000,000 miles) = 616 million miles

Distance after 1 year = 616 million miles/365 = 1.7 million miles

Sounds far, but that is only about 7 lunar distances. Plenty of time in Earth's influence to tweak the orbit.

The hard part of tracking asteroids is the fact that their orbital elements are changing all the time due to the influence of larger bodies and close encounters. 'Found' asteroids can become 'lost' if they are not monitored.

 

[Ripley]

...Sounds far, but that is only about 7 lunar distances. Plenty of time in Earth's influence to tweak the orbit...

How far does Earth's SOI extends wrt LD?
In other words, how many LDs is Earth's SOI?

 

[garyw]

How far does Earth's SOI extends wrt LD?
In other words, how many LDs is Earth's SOI?

A very rough calculation says 2.4LD.

Earths SOI is quoted as 925*10^3km

The moon is approx 384,400km away.

 

[Andy44]

Earth's SOI is only a useful concept when you're doing rough navigation calculations. Objects far outside the SOI are still influenced by the gravity of the heavier bodies such as Jupiter, Saturn, and Earth. Those organizations who track these objects account for this in their models as much as possible.

The tracking of the thousands of objects that may threaten Earth someday is dependent on modern computers and data storage technology. Had the idea of a dinosaur-killer been thought of a hundred or more years ago it would've required a lot of people with a lot of pencils to try to keep track of.