A Parting Look at 2012 DA14: Was This a Warning Shot from Space?

by Jason Major on February 18, 2013

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Asteroid DA14 seen from the 2.1 Kitt Peak telescope as it departed the vicinity of Earth. Credit: NOAO/Nicholas Moskovitz (MIT)

Asteroid DA14 seen from the 2.1-meter Kitt Peak telescope as it departed the vicinity of Earth. Credit: NOAO/Nicholas Moskovitz (MIT)

Just as anticipated, on Friday, Feb. 15, asteroid 2012 DA14 passed us by, zipping 27,000 kilometers (17,000 miles) above Earth’s surface — well within the ring of geostationary weather and communications satellites that ring our world. Traveling a breakneck 28,100 km/hr (that’s nearly five miles a second!) the 50-meter space rock was a fast-moving target for professional and amateur observers alike. And even as it was heading away from Earth DA14 was captured on camera by a team led by MIT researcher Dr. Nicholas Moskovitz using the 2.1-meter telescope at the Kitt Peak National Observatory in Tucson, AZ. The team’s images are shown above as an animated gif (you may need to click the image to play it.)

This object’s close pass, coupled with the completely unexpected appearance of a remarkably large meteor in the skies over Chelyabinsk, Russia on the morning of the same day, highlight the need for continued research of near-Earth objects (NEOs) — since there are plenty more out there where these came from.

“Flybys like this, particularly for objects smaller than 2012 DA14, are not uncommon. This one was special because we knew about it well in advance so that observations could be planned to look at how asteroids are effected by the Earth’s gravity when they come so close.”

– Dr. Nicholas Moskovitz, MIT

The animation shows 2012 DA14 passing inside the Little Dipper, crossing an area about a third the size of the full Moon in 45 minutes. North is to the left.

(For a high-resolution version of the animation, click here.)

Exterior of the 2.1-meter telescope of the Kitt Peak National Observatory (NOAO)

Exterior of the 2.1-meter telescope of the Kitt Peak National Observatory (NOAO/AURA/NSF)

According to the National Optical Astronomy Observatory, which operates the Kitt Peak Observatory, Dr. Moskovitz’ NSF-supported team “are analyzing their data to measure any changes in the rotation rate of the asteroid after its close encounter with the Earth. Although asteroids are generally too small to resolve with optical telescopes, their irregular shape causes their brightness to change as they rotate. Measuring the rotation rate of the asteroid in this way allows the team to test models that predict how the earth’s gravity can affect close-passing asteroids. This will lead to a better understanding of whether objects like 2012 DA14 are rubble piles or single solid rocks.

“This is critical to understanding the potential hazards that other asteroids could pose if they collide with the Earth.”

So just how close was DA14′s “close pass?” Well, if Earth were just a few minutes farther along in its orbit, we would likely be looking at images of its impact rather than its departure.*

Although this particular asteroid isn’t expected to approach Earth so closely at any time in the foreseeable future — at least within the next 130 years — there are lots of such Earth-crossing objects within the inner Solar System… some we’re aware of, but many that we’re not. Identifying them and knowing as many details as possible about their orbits, shapes, and compositions is key.

Even this soon after the Feb. 15 flyby observations of 2012 DA14 have provided more information on its orbit and characteristics., allowing for fine-tuning of the data on it.

According to the Goldstone Radar Observatory web page, the details on 2012 DA14 are as follows:
Semimajor axis                   1.002 AU
Eccentricity                          0.108
Inclination                           10.4 deg
Perihelion distance           0.893 AU
Aphelion distance              1.110 AU
Absolute magnitude (H)   24.4
Diameter                               ~50 meters (+- a factor of two)
Rotation period                   ~6 h  (N. Moskovitz, pers. comm.)
Pole direction                      unknown
Lightcurve amplitude        ~1 mag  (N. Moskovitz, pers. comm.)
Spectral class                       Ld  (N. Moskovitz, pers. comm.)

Goldstone is currently conducting radar observations on the asteroid. A radar map of its surface and motion is anticipated in the near future.

Read more about Dr. Moskovitz’ observations on the NOAO website here, and see more images of 2012 DA14 captured by astronomers around the world in our previous article.

A bright meteor witnessed over Russia on Feb. 15, 2013 (RussiaToday)

A bright daytime meteor witnessed over Russia on Feb. 15, 2013 (RussiaToday)

Also, in an encouraging move by international leaders in the field, during the fiftieth session of the Scientific and Technical Subcommittee of the Committee on the Peaceful Uses of Outer Space, currently being held from at the United Nation Office in Vienna, near-Earth objects are on the agenda with a final report to be issued by an Action Team. Read the report PDF here.

*According to astronomer Phil Plait, while the orbits of Earth and DA14 might intersect at some point, on the 15th of February 2013 the asteroid slipped just outside of Earth’s orbit — a little over 17,000 miles shy. “It was traveling one way and the Earth another, so they could not have hit each other on this pass no matter where Earth was in its orbit,” he wrote in an email. Still, 17,000 miles is a very close call astronomically, and according to Neil deGrasse Tyson on Twitter, it “will one day hit us, like the one in Russian [sic] last night.” When? We don’t know yet. That’s why we must keep watching.

About 

A graphic designer in Rhode Island, Jason writes about space exploration on his blog Lights In The Dark, Discovery News, and, of course, here on Universe Today. Ad astra!

Michael Porter February 18, 2013 at 8:26 PM

“if Earth were just a few minutes farther along in its orbit, we would likely be looking at images of its impact”

I’ve heard this a couple of times, but all the orbital paths I’ve seen make it look like the 2012 DA14′s path did not intercept Earth’s. Rather, it was a little farther out from the Sun (where “little” = a few Earth radii!). So how would it have hit us?

John Duff February 18, 2013 at 8:51 PM

“Well, if Earth were just a few minutes farther along in its orbit, we
would likely be looking at images of its impact rather than its
departure.”

In Phil Plait’s Google+ Hangout on Friday 15 Feb “Asteroid 2012 DA14 Nearmissapalooza” he stated that because the orbits of Earth and DA14 didn’t intersect, then no matter where Earth was in it’s orbit, they could never collide.

Jason Major February 18, 2013 at 8:59 PM

According to NDT, the orbits do intersect…. although maybe not at that exact moment in time on the 15th. Still, it will do us good to nail down its trajectory. https://twitter.com/neiltyson/statuses/302463281426214912

Michael Porter February 18, 2013 at 9:32 PM

I think that NDT might be using a looser definition of the word “intersect” — maybe as in “close enough to show obvious gravitational effects,” as in how the orbit of 2012 DA14 changed after the pass. The orbits are also close enough that there is a high likelihood of collision at some future date. But this time, early or late, the Earth wasn’t going to collide with it.

Jason Major February 18, 2013 at 10:26 PM

I’m pretty sure he wasn’t using a looser definition: https://twitter.com/neiltyson/status/302465798620975106

Michael Porter February 19, 2013 at 2:11 AM

He’s saying that a collision will happen at some point in the future. This is possible, as the orbit of the asteroid is perturbed by gravity — I heard somewhere that the period changed from 366 days to 317 after it passed the Earth. Some future orbital path may intersect with ours, but the current one didn’t, at least as far as an actual collision is concerned.

I’m saying that on this particular pass, it wouldn’t have hit the Earth even if we were ahead or behind in our orbit, because for this encounter the paths don’t intersect. The statement in the original article suggested they did.

klrog February 18, 2013 at 10:58 PM

Missing us by less than two Earth diameters is pretty good shooting. If not a ringer, then at least a leaner.

Jason Major February 19, 2013 at 3:56 AM

It’s the equivalent of having a fastball thrown at your head but missing by 15 inches. Enough to make you flinch, I’m sure.

The?egan?rchist February 19, 2013 at 3:46 PM

more like having a yeast cell come whizzing by your head at that distance. if it were like a baseball, the asteroid would have had to have been nearly 1.5 times the size of the moon!

bugzzz February 19, 2013 at 5:30 PM

Absolutely. Call it a warning shot or wake up call, and given added attention by the odd Russian coincidence. With any luck such an occurrence strengthens the funding for sciences and observatories.

The?egan?rchist February 19, 2013 at 7:06 AM

pity that budget cuts may force some telescopes on kitt peak, including the 2.1-meter telescope, to be shut down.

here’s my prediction, because we seem to be more concerned about profit and money making than scientific discovery and moral progress for the well-being of all humans and the benefit of the planet, an asteroid that could have been spotted well ahead of time to prevent an impact with earth will not be detected for lack of funding and will strike, killing millions or perhaps billions.

it always saddens me that we could be so much better than we are, so much wiser, more compassionate and understanding, but our greed, hubris and love of money get in the way.

Adheeb February 19, 2013 at 12:17 PM

The BIG ONE is yet to come. (Revelation 8:8)

Aqua4U February 19, 2013 at 6:04 PM

Gang speak?

Not ‘IF’ but ‘WHEN’…

then forgotten.

Momentary imagination glows like a fresh crater.

danangel February 19, 2013 at 2:46 AM

I was wondering how much our ‘close encounter’ effected its orbit. Thanks.

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