Update: we’re about an hour away here (it’s 1:30 UT as I write this) and I’m not seeing much more on this. I hope we’ll get some footage of it as it breaks up… in the meantime, check out this animation of what the asteroid will see as it comes in. AWESOME.

Stardust reentering Earth’s air
The meteor may resemble this picture of the
Stardust probe re-entering Earth’s atmosphere.

Thanks to my old friend Dan Durda, I just heard that an object a couple of meters across will enter the Earth’s atmosphere in a few hours! This poses no real danger to anyone, so don’t fret. A diameter of two meters means it’ll break up in our atmosphere, and most likely at worst rain down a few small rocks. You wouldn’t want one falling on your head, of course, but the odds of that are incredibly small.

The object is called 2008 TC3, and it was discovered very recently. It’s really faint, which is how they know it’s small. It’s predicted to burn up over Africa:

Steve Chesley (JPL) reports that atmospheric entry will occur on 2008 Oct 07 0246 UTC [Oct 6 at 10:46 p.m. Eastern US time] over northern Sudan.

That means it could break up over Darfur. Perfect.

Anyway, this will be a spectacular meteor! The meteors (what some people call shooting stars) you see randomly on an average night are as small as a grain of sand. Something as big as a grape would make a very bright fireball. A rock two meters across will be incredible.

As Dan pointed out to me, it would be nice if some astronomers can get a spectrum of it before it burns up, then again as it burns up. Then, the big hope is that specimens will then be found and collected. This would provide great data tying meteorites with observations of asteroids in space!

I’ll have updates as I hear them.

And didn’t I promise more posts about this kind of stuff?

2:30 p.m.: Well, here’s the first update: no real new info, but the Center for Astrophysics just sent out a press release. Here it is:

CfA Release 2008-19
For Immediate Release


A tiny asteroid discovered just hours ago at an Arizona observatory will
enter Earth’s atmosphere harmlessly at approximately 10:46 p.m. Eastern time
tonight (2:46 a.m. Greenwich Mean Time). There is no danger to people or
property since the asteroid will not reach the ground. It is between 3 and
15 feet (1-5 m) in diameter and will burn up in the upper atmosphere, well
above aircraft heights. A brilliant fireball will be visible as a result.

“We want to stress that this object is not a threat,” said Dr. Timothy
Spahr, director of the International Astronomical Union’s Minor Planet

“We’re excited since this is the first time we have issued a prediction that
an object will enter Earth’s atmosphere,” Spahr added. Odds are between 99.8
and 100 percent that the object will encounter Earth, according to
calculations provided by Andrea Milani of the University of Pisa.

When a meteoroid (small asteroid) enters the atmosphere, it compresses the
air in front of it. That compression heats the air, which in turn heats the
object, causing it to glow and vaporize. Once it starts to glow, the object
is called a meteor.

“A typical meteor comes from an object the size of a grain of sand,”
explained Gareth Williams of the Minor Planet Center. “This meteor will be a
real humdinger in comparison!”

The meteor is expected to be visible from eastern Africa as an extremely
bright fireball traveling rapidly across the sky from northeast to
southwest. The object is expected to enter the atmosphere over northern
Sudan at a shallow angle.

“We’re eager for observations from astronomers near the asteroid’s approach
path. We really hope that someone will manage to photograph it,” said

The Minor Planet Center, which is located at the Harvard-Smithsonian Center
for Astrophysics, serves as the worldwide clearinghouse for asteroid and
comet observations. It collects, checks and disseminates observations and
calculates orbits.

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for
Astrophysics (CfA) is a joint collaboration between the Smithsonian
Astrophysical Observatory and the Harvard College Observatory. CfA
scientists, organized into six research divisions, study the origin,
evolution and ultimate fate of the universe.

October 6th, 2008 1:50 PM by Phil Plait in Astronomy, Cool stuff, DeathfromtheSkies! | 65 comments | RSS feed | Trackback >

65 Responses to “Incoming!!!”

  1. ccpetersen Says:

    Dang you’re fast! I just got the NEO news about this 1 minute ago!

    You’re all over that Death from the Skies stuff, aren’t ya?

    :) :)

  2. drksky Says:

    Gah!!!! You do a search for “asteroid 2008 TC3″ and the first hit that comes up is some woo site called godlikeproductions. Sigh…

    Nothing cool ever happens over the US skies. :(

  3. tony873004 Says:

    Here’s an image I made with Gravity Simulator, showing it impact Earth with a speed of over 12 km/s.

  4. IVAN3MAN Says:

    If only this object would hit President Omar Hassan al-Bashir of Sudan, I might start believing in God, again.

  5. ccpetersen Says:

    Uh, dumb question time here: the PR I just got says it’s called: 8TA9D69 — assuming that’s the spaceguard survey number, correct?

  6. Kullat Nunu Says:

    Uh, dumb question time here: the PR I just got says it’s called: 8TA9D69 — assuming that’s the spaceguard survey number, correct?

    Same object, 2008 TC3 is an official designation issued by the Minor Planet Center.

  7. Joe Anderson Says:

    drksky, as someone who spends alot of time in and near the Tropopause, I can assure you that some very cool things occur over the US skies ;)

    Check out for example

    BTW, when I first heard the title of Phil’s new book - Death From The Skies - I was worried he had been on one of my flights!

    BA, thanks for the heads-up.

  8. ccpetersen Says:

    yes, I suspected as much… the official designation was not in the NEO news newsletter I just got…


  9. toomanytribbles Says:

    how far away can you see these things…? as far as southern europe maybe?

  10. NoAstronomer Says:

    Looking at the harvard link made me think of the Matrix movie - where the humans can read the numbers scrolling by on the screen to see what’s happening in the matrix.

  11. Stav Says:

    Anybody has info on how far away the meteor will be seen? I suppose my question is about both the curve of the earth (at what height do meteors burn?) and the brightness of the meteor.

  12. Thomas Miller Says:

    If only a meteor would burn up over my house.

  13. Francesco Says:

    I’m just wondering if this thing might be observable from central europe? Probably not, right?

  14. Jason Says:

    DrSky, please don’t make fun of us GLP’ers! We’re not all wacky woo woos!

  15. Naked Bunny with a Whip Says:

    Luckily, we can blast it with LHC black holes!

  16. Robert Simpson Says:

    This is really cool - how often do we get to know about these before they hit? Someone, somewhere needs a Twitter account we can all follow…

  17. rob Says:

    how do you calculate odds for these things? 99.8% was quoted above. Does one look at slight perturbations from the data for the trajectory and run multiple simulations to find 998 out of a 1000 hit earth? or is it related to the uncertainty in the trajectory data and to within 3 or 4 standard deviations they know it will hit earth? or do they have some other method?

    if it doesn’t hit earth, does that mean that mercuries retrograde motion is to blame? or, if it doesn’t miss earth does that mean mercuries retrograde motion is to blame?

    something tells me no matter what happens, someone will blame it on mercury. or obama.

    has anyone contacted bruce willis to see if he can do anything about this?

  18. ccpetersen Says:

    The amazing thing here is how well they’ve been able to track such a small object; the spaceguard dream may come true yet…


  19. Says:

    Pequeño asteroide descubierto hace pocas horas en un observatorio entrará en la atmósfera a las 2:46 h Greenwich [Eng]

    Esto no plantea ningún peligro. El objeto fue detectado hace unas horas en Arizona y es llamado 2008 TC3 y se espera su llegada a las 2:46 de la mañana hora de Greenwich. Tiene un diámetro de dos metros por lo que romperá en nuestra atmósfera, y …

  20. Christine Pulliam Says:

    The Minor Planet Center guys wouldn’t hazard a guess as to how far away it might be visible, but they recommend anyone even remotely in that part of the world give it a try. So to our friends in Europe, go out and look! Who needs sleep, especially when this thing could be as bright as the full moon as it comes in.

  21. tony873004 Says:

    “or is it related to the uncertainty in the trajectory data and to within 3 or 4 standard deviations they know it will hit earth? or do they have some other method?”

    That’s the way. It sounds like 2-3 standard deviations though.

  22. MarlowePI Says:

    Man, why does Darfur have all the luck?

  23. Dan Fischer Says:

    See this story for more details and links.

  24. Stav Says:

    @Christine Pulliam: I guess I understand that they don’t want to deal with a herd of dissapointed astronomers… what about a direct line of sight, though? How far up is the burning supposed to take place?

  25. Christine Pulliam Says:

    We’re talking tens of kilometers - maybe 30, 40, 50 km.

  26. Near certain hit at Oct 07 0246 UTC! - Bad Astronomy and Universe Today Forum Says:

    […] BA Blog: Incoming!!! __________________ 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0 0 1 1 0 1 0 0 1 0 1 1 0 1 0 0 1 1 0 0 1 0 1 1 0…. […]

  27. Jason Says:

    Phil, Any way to add a timezone to the blog entry footer? It’s not really useful in its current form… how do we have any idea when “tonight” is? Local time? Zulu? African time (since it’s supposed to hit in Africa) ?

    — October 6th, 2008 1:50 PM by Phil Plait in Astronomy, Cool stuff, DeathfromtheSkies! | 26 comments | RSS feed | Trackback > —-

    A. Fan

  28. Phil Plait Says:

    Jason, I gave the time/date of impact in the post in both UT and EDT.

  29. drksky Says:

    @Jason - I apologize if I’ve stereotyped you unfairly, but I called it as the first few posts on the front page deemed. Just that small sampling made me want to not look further :)

  30. firemancarl Says:

    Crap! I see 2012 got here early!!!!!!

  31. Russ Says:

    If this object were not 5 meter but 20 meters Would that make a difference in its impact?

  32. Jewel Says:

    This is just too cool. It’s pretty neat that we can see such a small object coming and track it.

  33. Bert Chadick Says:

    Is the ISS going to be in position to catch the spectra of the burn-up. Since they are up there they may as well do some science.

  34. Rick Says:

    I believe the Arizona Meteor Crater was formed from an object estimated around 50 meters in diameter. So if the albedo of this object varies greatly from estimation and the object is larger than expected, we could be in for quite a show!

  35. themadlolscientist Says:

    LOL @ Naked Bunny With a Whip and firemancarl!

    @ Bert Chadick: That’s what my Enquiring Mind wants to know.

  36. Thomas Miller Says:


    Bruce Willis wouldn’t be able to handle it.

    Armageddon was a horrible movie.

  37. jackINrome Says:

    Hey all. Am in rome, italy and heading out of town to a spot from where I miht see 2008 TC3. Anyone have any layman’s pointers on how to be watching/filming the right part of the sky (other than the advertised “Northeast to Southwest”. I dunno Google earth/sky coordinates perhaps? Also does the fact that it should be seen crossing from Northeast to Southwest apply just to Sudan? If not by how much would the orientation change if the observer is in italy?
    Any help greatly appreciated.

    happy watching

  38. Says:

    Pequeño asteroide descubierto hace pocas horas en un observatorio entrará en la atmósfera a las 2:46 h Greenwich [Eng]

    Esto no plantea ningún peligro. El objeto fue detectado hace unas horas en Arizona y es llamado 2008 TC3 y se espera su llegada a las 2:46 de la mañana hora de Greenwich. Tiene un diámetro de dos metros por lo que romperá en nuestra atmósfera, y e…

  39. IMForeman Says:

    You fools! It’s a ship! It’s probably a Wraith Dart! The last thing we need is a Wraith loose on Earth. ;)

    Sorry, I’ve been watching a bunch of Stargate episodes today.

    Oh, and Phil… I’d have gone with “Heads up!” over “Incoming!”

  40. Dan Fischer Says:

    The story is really ‘taking off’ now, with several more press releases and articles as well as interesting animations - all linked from here (sidebar of lead story). The animation from the point of view of the asteroid is particularly cool …

  41. Jim Oberg Says:

    ISS will be safe in the skies of Texas at the moment of impact, so the crew can sleep securely…

  42. Evolving Squid Says:

    @russ: Big time. Light show versus crater.

  43. Michelle Says:

    HOLY SMOKES. Are you serious??

    My god, for once I wished I was in africa right now. This is AWESOME. They could see something 2 meters across? Coming our way?

    Amazing. I love science. I love telescopes!

  44. toomanytribbles Says:

    *sigh* athens’ skies were quiet.

  45. Ian Maclean Says:

    OK…. 10 minutes since the predicted impact.
    Looking for Eye Witness Accounts now, will post more on my site
    as it comes to hand.

  46. I Am The Hill Sphere Calculator Says:

    The Hill Sphere of the rock before it vaporized was approximately 1.1 cm. from its center of mass. Stop me before I strike again!

  47. drbuzz0 Says:

    Regarding the impact point and time, what is the precision of these predictions? Are they about to predict that it will be in a given area with a high degree of certainty or are the measurements only good enough to predict that it will be most likely in a given area plus or minus a few hundred miles to within a given percent.

  48. toomanytribbles Says:

    i was an hour OFF?

  49. Mang Says:

    Small quibble, I thought there was an official dividing point at 5 m diameter below where something was a meteroid and above an asteroid.

    (Pluto must be having a chuckle over this).

  50. Christine Pulliam Says:

    No post-”impact” data into the Minor Planet Center as of 11:20 p.m. EDT. Hopefully some observations were made of the big event, despite its relatively remote location (as far as major observatories go).
    Sadly, the CfA press release had an error (as anyone who viewed the animation that Phil linked to probably noted) - the asteroid came in from the west/SW headed east/NE, not the other way around. Sorry for the mistake.
    Mang - I’m not sure of the meteoroid/asteroid dividing line. As with dwarf planet/planet/brown dwarf, I suspect it’s somewhat arbitrary.

  51. strahlungsamt Says:

    It’s the Lords of Nibiru that we were warned about some months back.

    Except that the LHC won’t be blasting a hole in the Van Allen Belts so they will just burn up and the Earth will be cursed.

    Now the Rapture will be cancelled.

  52. Asteroide a la vista : - bitácora de ideas, internet, hobbies, noticias y reflexión Says:

    […] “Esto no plantea ningún peligro. El objeto fue detectado hace unas horas en Arizona y es llamado 2008 TC3 y se espera su llegada a las 2:46 de la mañana hora de Greenwich. Tiene un diámetro de dos metros por lo que romperá en nuestra atmósfera, y en el peor de los casos caerán unas pequeñas rocas. Las probabilidades de caer sobre alguien son increíblemente pequeñas. (traducción google del articulo original) […]

  53. Francesco Says:

    Did anyone see this thing? I tried but didn’t see anything from central europe.

  54. The Sudan has been hit by an asteroid « Blogala Maho Says:

    […] Here’s a blog item about it. […]

  55. Marco Langbroek Says:

    A KLM/Air France aircrew might have spotted the fireball. See:

  56. Marco Langbroek Says:

    Oh: and you’d need to be within a few hundred kilometers of the impact point really to see the fireball. So no chance anyone in Europe would have seen the fireball itself.

  57. Marco Langbroek Says:

    Interesting: my other e-mail address seems to be on a moderation list?!?

    Re-post then:

    It seems that a KLM/Air France airliner aircrew might have observed the fireball. See

  58. tom Says:

    Supposedly the meteor was sighted by a KLM pilot (

  59. alfaniner Says:

    I’m kind of glad this showed up with little warning, the less to provoke hysteria.

  60. Sebastian Says:

    German magazine der Spiegel reveals that the presidential race has gripped the astronomy community as well:

    Alain Maury, one of the best known asteroids and comets professionals, quoted a colleague in the Minor Planet Mailing List: “I would name this asteroid after Alaska Governor Sarah Palin. Why? It is small, not particularly bright and will not leave any significant trace.”

    “Moreover, the presidential candidate John McCain, whose deputy Palin is slated to become, will probably remember when the asteroid has been formed. These heavenly bodies formed in the early days of the solar system and are thus about four billion years old.”

  61. A chinstrap named Tango Says:

    I live in Athens, Greece -Tribbles?.
    I won’t be very exact, I’m not an astronomer, and I’m not a native english speaker, so forgive my bad english.
    I was driving towards work at about 9:30am local time. As I was driving, I noticed something on the sky, I saw something in the SE sky.
    At first I thought it was the trail of a plane, but it didn’t quite seem like it. It was too short and too fluffy for that.
    Is there a possibility that this would be “it”?

  62. Eisnel Says:

    If the asteroid was scheduled to enter at 2:45am UTC, then I think it would be 4:45am or 5:45am in Greece time (not exactly sure about your time zone).

  63. toomanytribbles Says:

    A chinstrap named Tango … no, that wouldn’t have been it. As Eisnel said, it would have been early morning 5:45 — I was in Athens, waiting like a dork an hour earlier.

    Glad to know I wouldn’t have seen it anyway.

  64. Cuidado con los asteroides… Says:

    […] todos aquellos que estaban preocupados por el impacto de un asteroide contra la tierra. ← Anterior | Inicio Comparte esta anotación […]

  65. Mang Says:

    Ok what next? No you tube video. There’s a comment on Astroengine about a facebook posting of a photo from a balcony - but I don’t do facebook - and it’s the only reference I’ve seen. No Earth shattering kaboom (sorry Marvin).

    I assume that if it missed or grazed that Catalina *might* pick it up again. But I have no idea the odds or how predictable its path might be. If I’d have to guess, I’d say largely predictable with a small chance of going off at a weird angle.

    Of course, it looks pretty remote so it could take a while for someone to get to somewhere that they could upload a video. If the correct track was SW-NE someone in Khartoum might have caught it. I’d think out of 2M people there should be someone out at night with a camera.

    Shame if it were missed.

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