Cool animation showing asteroid DA 14's near miss next year

By Phil Plait | March 8, 2012 12:41 pm

Asteroid 2012 DA 14 was discovered a few weeks ago: a 40-meter wide rock on an orbit that brings it pretty close to Earth. Next year, on February 16, it will pass about 27,000 km from the center of the Earth (roughly 21,000 km from the surface), which is pretty close, but still a clear miss.

I wrote about this asteroid earlier this week, and the comments have been pouring in. People are asking if it will hit (no), if the Earth’s gravity will change the orbit of DA 14 (yes), have astronomers accounted for that (yes), and will it ever hit us sometime in the future (we don’t know; see below). One commenter, Chris Laurel, created a wonderful photo-realistic animation of the pass of the asteroid using software called Cosmographia, and, well, I think it will answer most people’s questions and fears:

Isn’t that cool? I did some spot checking using the JPL numbers and diagrams, and this looks pretty accurate to me. You can see how it approaches and misses us, and then he backs out a bit to show that the asteroid’s path is warped significantly by Earth’s gravity. So, to be very clear: next year, in February, this rock will miss us.

However, the amount the orbit is changed by Earth depends on precisely how close it comes, and we can’t measure the orbit that accurately just yet, even though we know it well enough to know it will miss. So what we really need are as many telescopes watching this event next year as possible for as long as possible. That will greatly reduce the uncertainty in the asteroid’s position over time, and allow for a good measurement of the orbit. It’s overwhelmingly most likely that the Earth’s gravity will put the asteroid into an orbit where it will miss us again for some time to come, but the only way to be sure is to really nail down its orbit.

I’m sure there will be an organized campaign with observers all over the world to do this. I’ll post more about that when I hear more, probably in the next few months.

Related Posts:

No, asteroid 2012 DA14 will not hit us next year
Asteroid 2011 AG5: a football-stadium-sized rock to watch carefully
My asteroid impact talk is now on TED!
Just to be clear: asteroid YU55 is no danger to Earth
Media FAIL *again* (HuffPo and Apophis edition)
Debunking doomsday

CATEGORIZED UNDER: Astronomy, contest, Pretty pictures
MORE ABOUT: 2012 DA14, asteroid, impact

Comments (50)

  1. Hamp

    So How visible will this be from Earth? Telescope? Binoculars? Naked eye?

  2. Tony

    What kind of damage could the rock do if it did hit?

  3. Obollzzor

    Will the asteroid affect any of the nearby satellites orbits? Like small changes in their orbit or so, or is the asteroid traveling too fast for that to happen?

  4. Gary Miles

    I noticed from the video that the asteroid does not appear to follow a path along the orbital plane. Isn’t this unusual?

  5. This makes the big sky theory seem so small! But a miss is a miss, not that it will ever sience the nutters, nor will a close call really motivate some to take rational precautions to protecting our civilization. Nothing’s ever easy, not are the differences always clear. :)

  6. Chris Laurel

    Gary: The orbit of the asteroid is inclined about 10 degrees with respect to the ecliptic before the Feb 15, 2013 approach. The effect of Earth’s gravity during the encounter adds about another 1.5 degrees to the inclination.

    It *appears* to be moving almost perpendicularly to the Earth’s orbit in the final scene of the animation because the trajectory of the asteroid is plotted relative to the Earth’s position. So while the asteroid actually is moving in an orbit similar to the Earth’s, the plot only shows part of the motion that is *different* than the Earth’s.

    I’ll try and create another animation that plots the 2012 DA14’s orbit with respect to the Sun during the Feb 15, 2013 encounter. You’ll be able to clearly see that the orbit of 2012 DA14 isn’t too different than Earth’s, but it will be harder to see the alteration to the DA14’s orbit caused by Earth’s gravity.

  7. Chris

    For an even better effect, play the Jaws theme while the animation is playing.
    da dum, da dum, da dum….

  8. Pete Jackson

    Does the asteroid really spin as fast as shown in the animation? That would create centrifugal forces much higher than the gravitational force of the asteroid, throwing off any soil or loose bits. And would disrupt the asteroid itself into pieces if it were just a ‘rubble pile’.

  9. Dre


    Note the clock at the top of the screen. It’s not a “real time” animation.

  10. Drew

    So I know the risk of impact in 2013 is nil, but I do have a question. The meteor is ~40-m wide. Realistically, if a 40-m object were to enter into the atmosphere on an impact trajectory, aside from the actual area of impact wouldn’t the effect on the Earth be pretty negligible?

  11. Chris Laurel


    As Dre noted, the time rate in the animation is sped up (otherwise it’d be a seriously dull video.) I suspect that’s the reason you think it’s rotating too quickly.

    We don’t know much about 2012 DA14 right now other than its orbit and approximate size. The shape model and rotation rate used in the animation are just guesses. The video shows 2012 DA14 completing one rotation every three hours. This is plausible for an asteroid of its size, though there are others spinning much faster: the 30 meter diameter asteroid 1998 KY26 has a rotation period of only 10.7 minutes!

  12. ceramicfundamentalist

    Larian: “not that it will ever sience the nutters”

    i’m sure this is a typo and you meant “silence” the nutters, but, just once, i wish someone would sit those nutters down and *science* the heck out of them. maybe then they’d get it.

  13. done

    What if it hits our moon? After all it will invade the space between our earth and It.
    wouldn’t that be a bit of a problem?

  14. Chris

    @13 done
    The Moon is even further away than any of our satellites. If it’ll miss the Earth, it’ll safely miss the moon.

  15. done — 2012 DA14 definitely won’t impact the Moon next year, but it’s certainly possible that it might in the future. If so, let’s hope it’s on the near side so we can watch the impact. (Though I couldn’t do more than make a guess as to whether it’d be naked-eye visible from Earth. Maybe if the Moon’s at first or third quarter, the asteroid impacts in the shaded part of the Moon’s visible suface, and it’s nighttime at the observer’s site.)

  16. jearley

    #10- Drew-
    A 40m asteroid can do quite a bit of damage locally. Depending on composition, it might airburst, such as Tunguska or impact the surface, such as the Barringer Crater in AZ. In both cases, there was a lot of damage over a wide area. The Barringer impact was from an estimated 50m diameter Ni-Fe meteorite/asteroid. The Tunguska event was from a similarly sized object, quite probably of stony composition.

  17. donald Branscom

    40 meters is .024 miles!!!!

    And you are not worried?

  18. Jeffie Freedom

    Where will the moon be relative to the asteroid and the Earth during 2012 DA14’s approach? I suppose the moon’s gravity is also worked into all the equations of the pass? If 2012 DA14 were to be affected by a near pass or collision with another untracked body during it’s orbit, how big would that object have to be for it to influence the trajectory of 2012 DA14 enough for it to hit planet Earth. And if we did get really really lucky for whatever reason, what face of the Earth would it hit?

    I think something like this is more of an opportunity to try to figure out what we would do if we had discovered and impactor this late in the game. We have a real scenario with it’s own dynamics that we can try to hypothetically problem solve, and that’s a preferable situation than trying to figure out how to solve the problem for the first time when it’s real. SARS allowed health agencies the opportunity to see that some of their pandemic contingencies are not going to work, perhaps we could use a dry run like that with an asteroid.

  19. @jearley if da14 is 40 meters in space how big will it be after ablation effects during the atmospheric penetration phase ? Has anyone estimated the size of the objets de Barringer et Tunguska before they terminated their existence on terra firma, zero altitude or plus 1600 meters ?

  20. Woodbine

    Well, I don’t know about you so-called experts but until I hear otherwise I’m going with whatever Richard C Hoagland says. I’ve no doubt that NASA are covering up the fact that this alleged asteroid is in reality an alien spaceship. One with a message for all mankind. A(nother) game-changer….you’ll see!!!

  21. Johnny Nielsen

    Let’s assume it’s spherical and 50m across. Let’s also assume it consists of loose rock and has a density of 3g/cm^3. Without knowing much about the object, I think those are reasonable assumptions. (assumptions are the mother of all asses, but that’s another subject)

    Then it’s mass is 3/4*pi*(25m)^3 * 3000kg/m^3 = 1.1*10^8 kg.
    Nasa has it listed as travelling at 13km/s.
    The kinetic energy it has is the good old E=mv^2, so…
    E = 1.1*10^8kg * (13km/s)^2 = 1.867*10^16J = 18.67PJ.
    1MT is roughly 4.1PJ, so we’d have the equivalent of a 4.5MT bomb going off.

    You can find China’s Nuclear test No. 6 on youtube to get a sense of what an airblast that size would do.

  22. Neat! Cheers for this – good work. :-)

  23. Matthew Ota

    I plugged the orbital information into my astronomy program of choice, TheSkyX Professional. It shows that the close approach will be visible in the southern hemisphere only.

  24. Rajesh Kalmady

    @21 Johnny Nielsen

    Shouldn’t it have been (4/3)*pi*(25m)^3 * 3000 = 1.96*10^8 kg instead ?

    Also the kinetic energy should have been (1/2)*mv^2

  25. Nigel Depledge

    Johnny Nielsen (21) said:

    Then it’s mass is 3/4*pi*(25m)^3 * 3000kg/m^3 = 1.1*10^8 kg.

    Erm . . . should not this be thus:

    4/3*pi*(25)^3*3000 = 1.96*10^8 kg?

  26. Sandman

    What do Phil Plait and a glamorous Sun Page 3 model have in common?

  27. OneofNone

    @17. donald Branscom:

    40 meters is .024 miles!!!!

    And you are not worried?

    Hey, Jupiter is much bigger than Earth. And yes, I’m not worried. OK, I know you’re kidding.

    In both cases Science tells us there is no hit in the near future. Neither 2013 with DA14 nor in the next millennia with Jupiter.

  28. OneofNone

    @18. Jeffie Freedom:

    Where will the moon be relative to the asteroid and the Earth during 2012 DA14′s approach?

    Stop the animation around the 0:15 mark.

    At 0:38 you can see Venus behind the Earth. So DA14 roughly approaches from the night side.

    Then stop at 0:56, this probably answers your question.

    @14. Chris:

    @13 done
    The Moon is even further away than any of our satellites. If it’ll miss the Earth, it’ll safely miss the moon.

    As you can see from the 0:56 mark, this statement is not correct. The nearest point of DA14’s orbit is below the moon distance. But this is not a guarantee for a miss. The core question is, where are DA14 and the moon when DA14 is at moon distance from the Earth.
    DA14 could leave the earth to a contact with the moon. It does not next year.
    [Doc Brown (modified)] Think three-dimensional [/Doc]

  29. Johnny Nielsen

    It most surely should have been 4/3. Silly me :)
    In which case we arrive at 33PJ or just shy of 8Mt.

  30. Wow, very slick, Phil. Thanks for showing us that… and I mean that in a good way, not in the MST3K sense (wink).

    Never mind that it’ll totally miss us; the fact that it’ll pass inside the orbital altitude of geosync satellites means that the Drudge Report will have a huge-assed all-caps headline at the top of the page reading IT’S COMING RIGHT FOR US! with that stupid animated spinning police light gif over it.

  31. Johnny Nielsen

    And that should be ½ that, 4Mt. Been too long since I did newtonian physics problems :/

  32. Nigel Depledge

    @ Sandman (27) –
    Ooh, now that’s tantalising. I cannot view YouTube from work, so you leave me to guess.

    Is it to do with posing naked behind a telescope?

  33. Ah…A chance to practice,on how to destroy or deflect…at least to build a lite-house
    on it…!

  34. brainfisch

    of course there is no risk of an impact in 2013.
    Everybody knows that the world will already have ended in december 2012.

  35. carbonUnit

    Seems like a lot of these close pass objects manage to come back, despite the change in orbit caused by Earth’s gravity well. Is there some sort of principle at work that keeps the orbits of Earth and asteroid synchronized despite modest deflections? I would think that such passes would change the asteroid’s orbit enough that it would not be likely to meet Earth again anytime soon. (Or is this a case of a biased sample?)

  36. Sandman

    @Nigel (33)

    The acting debut for Page 3 model Rosie Jones is the lead in a short mission to Mars movie that opens with a quote from some astronomer named Plait.

  37. Ian

    So when is it coming back?

  38. Olaf

    @Johnny Nielsen
    Yes the kinetic energy is big before it enters the atmosphere.
    But the atmosphere dissipates the energy and thus object will lose enormous energy.

    The object explodes at 10 km height above the surface and the energy is even spread over a larger volume. Fragments will impact and that is bad news if you are standing in the part of a fragment.

    The airblast will shatter glass at 1 km from the impact zone.

  39. OneofNone

    @36. carbonUnit:

    Seems like a lot of these close pass objects manage to come back, despite the change in orbit caused by Earth’s gravity well. Is there some sort of principle at work that keeps the orbits of Earth and asteroid synchronized despite modest deflections?

    Of course they come back.
    That’s the principle of any orbit. You get the same path again and again, until a change happens. When a change happens, you get a new path to repeat again and again.

    Now think again: When the Earth changes the path of an asteroid, it is near the earth. So it will come back to the point where the change in orbit happened. This is unavoidable, there is no magic principle.

    It is just usually the Earth is not in that location when the asteroid comes back. But the orbits still nearly intersect at one point.

  40. James

    If it’s going well inside the geosynchronous satellite orbits, then won’t it collide with our large amount of space junk we’ve piled up out there?

    That would certainly alter it’s course somewhat.

  41. Kevin in Sacramento

    If DA14, a 45 meter object, collides with a space wrench, it will have no affect on the known standard deviation due to the differences in kinetic energy. In other-words, it does not change the 2013 passage.

  42. JrJR

    Did anybody take the gravitation of the Sun and Jupiter into account while producing this simulation? Why do I ask about Jupiter? Because it’s gravitational pull is significant enough to leave the Sun wobbling like some dude pulling off a hammer throw. If there’s no significant difference, no biggy, but otherwise it would still be nice to know.

  43. Kevin in Sacramento

    @46. JrJR

    JPL considers perturbations by all planets, a few of the larger asteroids, a few other physical usually small forces, and requires numerical integration.

    As of March 30 (observation arc of 35 days), the nominal orbit shows it passing 0.00041 AU (61,000 km; 38,000 mi) from the center-point of the Earth.

  44. JrJR


    But really I did get that, and a quick google search identifies the earth’s radius at 3959 mi so we are still in the green 😉

  45. Kevin in Sacramento

    As of May 1, 2012, the odds of impact on 2020-Feb-16 are 1 in 37,037,000.


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