UARS update 2: new predicted re-entry at 00:58 UTC

By Phil Plait | September 22, 2011 9:07 pm

The Center for Orbital and Reentry Debris Studies has updated their predicted re-entry time for NASA’s UARS satellite. It is now three hours later than before: 9/24 at 00:58 UTC, which puts it in the middle of the south Pacific:

Mind you, the uncertainty on this is still +/- 7 hours, so we’re a long way from knowing just where it will come down.

For more details, please read this earlier post (and you might as well read this one as well for the background info).

MORE ABOUT: re-entry, satellite, UARS

Comments (37)

  1. Titan

    It just needs to be about +20 minutes and it will be visible to me!

  2. Mike

    Oh great, so there’s still a chance it’ll find me.

    Am in Southland, New Zealand…

  3. Christopher Jablonski

    Isn’t it funny how we perceive risk? I look at that map, and I look at that yellow line crossing over Chicago, and all I can think is it’s going to hit me. Yet I’m some untold orders of magnitute more likely to die in a car accident tomorrow. Or the next day. Or the next day …

  4. VinceRN

    Looks like the PNW is still on the outer edge off possibility. I would love to have to explain to the insurance company that a chunk of steel fell through my roof from space.

  5. Infinite123Lifer

    Christopher Jablonski says:

    “Isn’t it funny how we perceive risk?”

    Indeed. Perception is a clever game.

    I bet if a satellite were to come crashing down everyday for every time you have ever been in a car you might not worry so much about that space gear landing on you after awhile.

    I concur.

    Ah C’mon…UTC…
    looking for a converter that goes from UTC to standard
    still looking
    The current Unix epoch time is 1,316,752,394 and ticking which began 01/01/1970 for the GMT date-time beginning?
    and if you live on the west coast 00:58 UTC is approximately…
    still looking for a converter that works…
    still looking
    UTC is “coordinated universal time” abbreviated as UTC and formerly known as “Greenwich mean time”(actually it appears GMT and UTC have differing definitions) or “Zulu time” or “universal time” or “world time”
    still looking
    so subtract 7 hours
    still looking…jeez
    so I guees you just subtract 7 hours from 00:58 UTC (which I am guessing goes from 00:00 to 23:59) but if I take 7 away from that I get 17:58, then subtract 12 and I get about 5:58 am.

    I think that I am incorrect
    I read a chart that said 01 UTC time was equivalent to about 6 pm for PST.

    And one converter said to convert to military time from UTC by adding or subtracting the numbers then subtract 12 from that to go to standard.

    So is UTC the same as military without the leap seconds being added?

    And can anybody clear this up for me? If they have the time.
    :) pun intended.

    Also is Washington lie in Pacific Daylight Time and the difference between that and Pacific Standard Time is????

  6. Bill Jenkins

    UTC…lol. I thought the same thing, Infinite123Lifer… Then I found this website:

    Saturday, September 24, 2011 at 00:55:00 UTC =

    Friday, September 23, 2011 at 8:55:00 PM Eastern
    Friday, September 23, 2011 at 7:55:00 PM Central
    Friday, September 23, 2011 at 6:55:00 PM Mountain
    Friday, September 23, 2011 at 5:55:00 PM Pacific

    (Daylight time for all…so if you live in those bizarre areas that don’t practice daylight savings time, adjust accordingly.)

  7. Don

    timeanddate dot com is the place to go for time conversions and calendars.

  8. Just watched UARS go overhead. Possibly my last chance before it reenters the atmosphere tomorrow. Pretty too, I was outside Waimea and the satellite went right over Mauna Kea. The bright satellite was skimming through high cirrus lit by the last rosy glow of sunset. Notably brighter than the predicted -1 magnitude, I would say at least another mag brighter, with a couple flashes near -3 or -4.

  9. Shatners Basoon

    We’re all going to die!!!

  10. alfaniner

    So, about 17.5 hours from the time of this post. or about 9pm EST?

  11. Am i right to understand that it’s periapsis is over the pacific, and because of that it is unlikely to re-enter 5-10 minutes sooner or later, but instead is likely to re-enter an orbit or two off?

  12. krankie UK

    I love the way NASA are still saying it won’t pass over North America despite the latest prediction of re-entry on a later orbit doing precisely that.

    Good news for the UK though. The three preceding orbits do fly over us but this one doesn’t.

    The new prediction is on an orbit that also flys over Libya. The odds that it takes out Colonel Gadaffi just shortened. LOL.

  13. CameronSS

    @Valtra: I hope that’s what they mean, otherwise I’m confused as to how they can have a 14-hour window, but dead-centered down to the minute. Seems like if it’s +/-7hrs they should just call it 0100UTC.

  14. MHS

    What I don’t understand is how they ruled out a reentry over North America yesterday, even though this graph clearly shows it is still very well possible.

    Anyway, judging by this graph alone it is most likely to come down either in the North Atlantic or in the South Pacific. Still hoping for a nice flash over Holland though :).

  15. @ 12 MHS:
    Best for us in Holland would be decay near 21 UTC, 23rd.

    At this moment, projected re-entry times are still shifting by several hours with each new orbital update so anything is still possible.

  16. MHS

    @13. Marco Langbroek
    Thanks! I’ll be looking up just in case :).

  17. Neil NZ

    Hey, the South Pacific is a big place, but it is still a little too close to home!

  18. Steve

    The white lines showing the day/night boundary nicely illustrate that today is the equinox :-)

  19. Cool. If that map is accurate, and I’m reading it correctly) it looks like it could be passing almost directly over my hear about 35minutes after predicted re-entry. That’s a little after midnight here, and I was hoping to be out with my scope anyway assuming the clouds let up (current forecast is 50/50).

  20. icemith

    I would love to have had a timeline IN the post, as it is impossibe to determine anything really concrete as there is no indication as to when the post was actually … er, posted. My mailbox says, “Today, 3:34pm”, today being Friday, 23rd Sept., 2011, here in Eastern Australia.

    Now I’m sure that that time is not the actual time BA (hi, Phil), posted, just the time I received it via Feedblitz. I am typing this at 8:45pm or the UTC time of 10:45 am (Friday). Actually I prefer the 24 hour clock, but as the post is written in ordinary clock time, and I imagine that to be a clockface, you know the round thing with hands.

    So at this time, exactly is/WAS the UARS Satellite, and which orbit was it in and over which point of the surface of the Earth? Maybe somebody can say it just passed overhead.

    This point of time reference, position and direction travelling, and the actual day posted is very important to others of us who are in different parts of the world. Much as I like New York, (visited), London, (not yet), and Sydney, (where I live), they are not the center of the world, and the only accepted time reference is UTC, then in these posts, it should at least, be provided as well as the local variants for those in the same timezone.



  21. Wzrd1

    Space-track is holding reentry at
    Report Date/Time 2011-09-23 00:17:00 GMT
    Predicted Decay Time 2011-09-24 00:42:00 GMT +/- 15 Hours
    Predicted Decay Location 46.1° S, 112.7° E
    Direction descending
    Inclination 56.9°
    Revolution Number 10917
    High Interest Object Y
    Next Report 12 Hours

  22. Lorena

    death from the skies!! it’s real!! 😀 😀 I hope it doesnt hit me in the head XD XD

  23. dcsohl

    icemith@17: At the bottom of the post, under all the Facebook/Twitter stuff, it says, “September 22nd, 2011 9:07 PM”. Now, Phil is in Colorado, so that’s MDT (UTC-6), so it was posted at 03:07 UTC on the 23rd. (And on November 6, it will change to MST which is UTC-7.)

    I’m always a bit surprised that it is MDT; that Phil’s blog doesn’t timestamp in UTC or maybe Julian Day Number. :)

  24. BigBob

    Here’s where you get your UARS updates:
    look towards the bottom of the list would give you a live display of where UARS is but their servers are overwhelmed!
    So try instead, then click on UARS, then click on Orbit – that’s where she is. Refresh the page to get an updated position.


  25. JupiterIsBig

    So NASA launched it – I’m 100% sure they knew it would be a hazard when it crashed. NASA ain’t commercial folks – why didn’t they save some fuel to actually guide it into the southern ocean ? At -50 deg latitude, there ain’t much to hit !
    1 in 3200 is many times greater than your chances of winning Lotto, or NASA’s chance of getting proper funding compared to Haliburton !

  26. Hang in there UARS! Delay just a few minutes & you can land in my woods!
    Pretty please with neutrino sprinkles?

  27. Mike notUSA

    NASA: “Re-entry is possible sometime during the afternoon or early evening of Sept. 23, Eastern Daylight Time. The satellite will not be passing over North America during that time period.”
    As if it is no problem if a non-american gets killed or his property gets smashed by a chunk of the UARS.
    The arrogance and contempt of NASA. Urrgh.

  28. Trebuchet

    Hmm, missing here by a little over two orbits. What’s the orbital period? That low, I’d guess it’s down to not much over an hour?

    @Jupiter is big: 1 in 3200 is the chance of it hitting someone, anywhere in the world. For the chance of hitting you, divide by about 7 billion. Your chances of winning the Lotto are probably better.

    Edited to add: Also, It was originally intended that it would be retrieved by the space shuttle, same way it was launched.

  29. Abuelo Paul

    I have to admit, as I have been following this story about 4 days now, NASA seem very unconcerned about being exact in the final re-entry point, other than to re-assure the citizens of the good ole USofA that it won’t hit them. And who cares about the rest of the world? There is no world outside the US. We are led to believe. Well hello. I am in the Canaries, British, and just as concerned as to where it may fall. Mainly cos I want to get pictures of the burnout.
    So Please señores at NASA. MORE INFORMATION.
    Your TIP messages give more info , and even that is spartan. “more information in 12 hours” there may not be 12 hours to prepare tripods and stuff.
    21st century technology is too good to be plausibly denying where this debris will finally crash through. So stop the kidology, get real and spill the beans.

  30. Abuelo Paul

    And as an afterthought. it may be hard work for the Americans to follow a Universal Time Clock notation but it is far more difficult for the rest of us to try convert back from EST, PST west coast sun down or Hawian 5 o’clock time stamps on all things NASA. Stop being so insular and realise that timepieces and notation have been around longer than America.

  31. Pete Jackson

    Now it’s at:

    24 SEP 2011 @ 03:16 UTC ± 5 hours

  32. Wzrd1

    Report Date/Time 2011-09-23 15:33:00 GMT
    Predicted Decay Time 2011-09-24 03:34:00 GMT +/- 9 Hours
    Predicted Decay Location 36° S, 54.8° E
    Direction descending
    Inclination 56.9°
    Revolution Number 10920
    High Interest Object Y
    Next Report 6 Hours

  33. Trebuchet

    Hmm, only half an orbit from me now. Could be interesting this evening.

  34. Lorena

    hehe I’m from argentina and I am used to GMT 😀 so when you say UTC I have no idea what you were talking about 😀 so even if you put UTC for the rest of the world, maybe we don’t know what it is, I had to search what UTC is :)

  35. Tom (H. Type)

    If the reentry time is just 20 min late, it could my house…I’m glad I still have that big drum of SkyLab repellent sitting in the back yard. Bought that back in 79…Pretty good investment, I’d say. 😀


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