APOD: Asteroid 2012 DA14 Passes the Earth (2013 Feb 17)

[APOD Robot]

Asteroid 2012 DA14 Passes the Earth

Explanation: There it goes. That small spot moving in front of background stars in the above video is a potentially dangerous asteroid passing above the Earth's atmosphere. This past Friday, the 50-meter wide asteroid 2012 DA14 just missed the Earth, passing not only inside the orbit of the Moon, which is unusually close for an asteroid of this size, but also inside the orbit of geosynchronous satellites. Unfortunately, asteroids this big or bigger strike the Earth every 1000 years or so. Were 2012 DA14 to have hit the Earth, it could have devastated a city-sized landscape, or stuck an ocean and raised dangerous tsunamis. Although finding and tracking potentially dangerous asteroids is a primary concern of modern astronomy, these small bodies or ice and rock are typically so dim that only a few percent of them have been found, so far. Even smaller chunks of ice and rock, like the (unrelated) spectacular meteors that streaked over Russia and California over the past few days, are even harder to find -- but pose less danger.

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[Ann]

It's a nice and interesting video, and I was glad to see it.

Even so... talk about one piece of space rock being totally, totally upstaged by another!!!

Ann

[Moonlady]

Was it visible to the naked eye?

[Case]

Was it visible to the naked eye?

Apparently not:

[...] the asteroid will travel rapidly from the southern evening sky into the northern morning sky with its closest Earth approach occurring about 19:26 UTC when it will achieve a magnitude of less than seven, which is somewhat fainter than naked eye visibility. [...]

[Boomer12k]

WoW, Cooooooool, someone was actually able to capture it... neat.


:---[===] *

[Sinan İpek]

Is there any connection between this asteroid and the meteorid that fall in Russia the same day?

[Boomer12k]

"To boldly go, where no man has gone before." Dooo, Dooooo, do, do, dodo..doooooooo...


:---[===] *

[fausto.lubatti]

Wonderful video: thanks for sharing!

[owlice]

Is there any connection between this asteroid and the meteorid that fall in Russia the same day?

No, there is no connection between the two. Please see here: http://www.nasa.gov/mission_pages/aster ... 30215.html

Thanks!

[MargaritaMc]

WoW, Cooooooool, someone was actually able to capture it... neat.


:---[===] *

I am going to indulge in some quite unjustified pride ( as I have no connection to the Observatory on Mount Teide ) and point out that this superb video comes from my home island of Tenerife. Daniel López apologises on the Vimeo blurb for the shaking of the image, caused by high winds, but it seemed rock steady to me.

Margarita

[Joe Stieber]

This is indeed a fine video of the 2012 DA14 pass. However, I think it pales compared to seeing it with one’s own eye. Even though DA14’s motion and brightness had decreased substantially by time it was accessible from my location in New Jersey, USA, I was able to follow it in my telescope from 7:15 to 8:15 pm local time on 15-Feb-2013 (00:15 to 01:15 UT on 16-Feb-2013). At 160x, movement could be seen in real time, and motion was obvious when DA14 passed near a background star. It was a magical sight!

Joe

[neufer]

I am going to indulge in some quite unjustified pride ( as I have no connection to the Observatory on Mount Teide ) and point out that this superb video comes from my home island of Tenerife. Daniel López apologises on the Vimeo blurb for the shaking of the image, caused by high winds, but it seemed rock steady to me.

Hardly ideal conditions: "Asteroid 2012 DA Track 14 from 21:00 to 22:46 UT on 15/02/2013
from the Observatorio del Teide. Strong wind gusts of 55km / h make the image shake."

This is indeed a fine video of the 2012 DA14 pass. However, I think it pales compared to seeing it with one’s own eye. Even though DA14’s motion and brightness had decreased substantially by time it was accessible from my location in New Jersey, USA, I was able to follow it in my telescope from 7:15 to 8:15 pm local time on 15-Feb-2013 (00:15 to 01:15 UT on 16-Feb-2013). At 160x, movement could be seen in real time, and motion was obvious when DA14 passed near a background star. It was a magical sight!

But you were only two hours after the end of Daniel López's video...
which explains why 2012 DA14 is slowing down thru-out his video.

How to find and follow asteroid 2012 DA14 during Friday’s flyby

[b][color=#0000FF]World map with time zones. The area inside the red circle shows very approximately where the asteroid will be visible in a dark sky when it’s closest and brightest. Map credit: Wikipedia[/color][/b]

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by Astro Bob

Despite its proximity, 2012 DA14′s tiny size means not even the largest telescopes will show it as more than a star-like point of light. If you live in eastern Europe, Asia or Australia, you’ll see the asteroid at its closest, when it not only be brightest but moving fastest. I’ve seen a few Earth-approaching asteroids, and they really can book across the sky, but few travel as fast as this one will. In just three hours centered on closest approach, 2012 DA14 will zip from the Southern Cross all the way to the Bowl of the Big Dipper!

It reaches peak brightness around 1:24 p.m. (CST) or 7:30 p.m. in London, England. While the sky will be dark there at that time, the asteroid will still not have risen in the east. We have to go travel farther east and south to catch it at its brightest. Let’s pick Athens, Greece. There the the sky will be dark early enough to spot the asteroid at its brightest (magnitude 7.4) low in Virgo around 10 p.m. local time using standard 40-50mm binoculars. Observers should look for a dim “star” slowly moving from south to north in the field of view.>>

[Psnarf]

Nya, ya missed me!

That rock had to have been affected by Earth's gravity. That's what is keeping the geosync sats up there. Has anyone processing the data determined its new orbit?

[Joe Stieber]

But you were only two hours after the end of Daniel López's video...
which explains why 2012 DA14 is slowing down thru-out his video.

Looking at ephemerides from the Minor Planet Center, the apparent motion of DA14 during the pass (in arc seconds per minute of time) was approximately:

15-Feb, 21:00 UT: 1360 (start of Lopez's video)
15-Feb, 22:46 UT: 470 (end of Lopez's video)
16-Feb, 00:15 UT: 275 (start of my observation)
16-Feb, 01:15 UT: 195 (end of my observation)

Note that 1360 arc seconds is about three-quarters of a moon diameter.

Joe

[Chris Peterson]

That rock had to have been affected by Earth's gravity. That's what is keeping the geosync sats up there. Has anyone processing the data determined its new orbit?

Yes. The orbit is already understood by accounting for the gravitational perturbation of the Earth. This encounter substantially altered the orbital elements, reducing the orbital period by 14% and converting DA14 from an Apollo class asteroid to an Aten class asteroid (that is, from an asteroid with a semimajor axis greater than 1 AU to one with a semimajor axis less than 1 AU).

This was all understood and calculated before the encounter. However, there is a degree of uncertainty in the orbit that can't be eliminated by mathematics alone, so bodies like this are regularly observed and the orbital elements tweaked based on those observations.

[bystander]

That rock had to have been affected by Earth's gravity.

Possible Seismic Activity on Asteroid 2012 DA14
NASA Science News | Dr. Tony Phillips | 2013 Feb 14

[neufer]

Nya, ya missed me!

• Three Billy Goats Gruff

Code: Select all

Airburst estimates for a stony asteroid with a diameter ranging from 30 to 85 meters

Diameter 	Kinetic energy 	Airburst energy    Airburst altitude 	Average frequency
------------------------------------------------------------------------------------------------------------
30 m  	  	   708 kt	   		 530 kt  		    16.1 km  		    185 years
50 m  	  	   3.3 Mt 		 	  2.9 Mt 		      8.5 km 	   	  764 years
85 m         	16.1 Mt 		  	15.6 Mt 		     0.435 km	  	  3300 years

That rock had to have been affected by Earth's gravity. That's what is keeping the geosync sats up there. Has anyone processing the data determined its new orbit?

[img3="2012 DA14 changing "its orbit" by passing thru the ring"]http://upload.wikimedia.org/wikipedia/c ... ews174.jpg[/img3]

Its orbit has constantly been reprocessed ever since it's discovery last year (just after its last pass by Earth). It will be reprocessed after the Goldstone Observatory radar observations from February 16 to February 20.

<<2012 DA14 was discovered on February 23, 2012, by the Observatorio Astronómico de La Sagra, Granada in Spain (J75) seven days after passing 2,600,000 km from Earth. In 2012 there was a cumulative 0.033% risk estimate (1 in 3,030) of 2012 DA14 impacting Earth sometime between 2026 and 2069. In 2012 it was also known that the asteroid would pass no closer to Earth's surface than 3.2 Earth radii during the 2013 passage. Eliminating an entry on the Sentry Risk Table is a negative prediction; a prediction of where it will not be.

On February 15, 2013 at 19:25 Universal Time, the asteroid passed 34,050 km from the center-point of Earth, with an uncertainty region of about 15 km. It passed 27,743 kilometers above Earth's surface, closer than satellites in geosynchronous orbit. The best observation location for the closest approach was Indonesia. Goldstone Observatory will observe 2012 DA14 with radar from February 16 to February 20.

The close approach to Earth reduced the orbital period of 2012 DA14 from 368 days to 317 days, and perturbed it from the Apollo class to the Aten class of near-Earth asteroids. Its next notable close approach to Earth will be on 15 February 2046 when it will pass no closer than 1,500,000 km from the center-point of Earth.>>

[mjimih]

Is our atmosphere particularly good at busting up space rocks? Does the fact that our air is 25% O2 help in burning up these rocks? If our atmosphere was just inert Nitrogen for example, would the meteors burn up in much the same way?
I'd be willing to assume that if we had an atmosphere twice as thick, we wouldn't have to worry about these pesky leftover-space shuttle-sized rocks any longer.

[Chris Peterson]

Is our atmosphere particularly good at busting up space rocks? Does the fact that our air is 25% O2 help in burning up these rocks? If our atmosphere was just inert Nitrogen for example, would the meteors burn up in much the same way?
I'd be willing to assume that if we had an atmosphere twice as thick, we wouldn't have to worry about these pesky leftover-space shuttle-sized rocks any longer.

The composition of the atmosphere isn't a significant factor, only the density. If we had twice the atmosphere, meteors would tend to break up and burn higher. But with enough mass, they'd still reach the ground, and meteorite falls would still be common.

[mjimih]

Ok cool. So in a perfect world hehe, we would like to have a little bit thicker atmosphere over us.

At least we seem to have a thick enough atmosphere to mostly bust up these nagging pint-sized meteors that are still the most common out there threatening us.

This one came in at a low angle very fast. If it had made a more direct shot at us, it would have been much worse correct?

[ta152h0]

Pedal to the metal .......

[mjimih]

http://www.youtube.com/watch?v=cUT8g8_Yd2Y

comin' at ya!

[alter-ego]

Was it visible to the naked eye?

Apparently not:

[...] the asteroid will travel rapidly from the southern evening sky into the northern morning sky with its closest Earth approach occurring about 19:26 UTC when it will achieve a magnitude of less than seven, which is somewhat fainter than naked eye visibility. [...]

From the beginning to end of the video, JPL Horizons lists the magnitude range as 8.5 to 10. Based on the video, the magnitude of the asteroid appears to range between ~8 to ~11 (the faintest stars visible in the video are ≈11.5) which which is in the ballpark with JPL's listings.

I am going to indulge in some quite unjustified pride ( as I have no connection to the Observatory on Mount Teide ) and point out that this superb video comes from my home island of Tenerife. Daniel López apologises on the Vimeo blurb for the shaking of the image, caused by high winds, but it seemed rock steady to me.

Hardly ideal conditions: "Asteroid 2012 DA Track 14 from 21:00 to 22:46 UT on 15/02/2013
from the Observatorio del Teide. Strong wind gusts of 55km / h make the image shake."

For the brighter starts, shaking is more evident in the video. My eye first caught the brightest star that passes through the field of view at the frame time of 4sec to 5sec. Curious to which star this was, I found it to be Alioth, the familiar 3rd star of the Big Dipper handle.

[Chris Peterson]

This one came in at a low angle very fast. If it had made a more direct shot at us, it would have been much worse correct?

Are you talking about the Russian meteor? It came in shallow, but very slow (~18 km/s, near the low end of the possible range). It was the low speed and shallow angle that allowed it to survive so far down into the atmosphere. Had it come directly down, it probably would have exploded much higher and no shock wave would have reached the ground at all.

[ta152h0]

Too soon to know if any pieces of the " Ural rock " been picked up yet ? During one of the videos I heard a loud crashing sound.