[UPDATE to the update (22:00 UTC): a new prediction just came out: tonight, September 23/24, at 04:04 UTC (midnight Eastern US time). The uncertainty is down to +/- 3 hours, and the location is the middle of the Pacific. Clicking the links below to CORDS or the image itself will take you to the most current prediction.]
The Center for Orbital and Reentry Debris Studies has updated their predicted re-entry time for NASA’s UARS satellite. It is now 9/24 (tonight!) at 03:16 UTC, which puts it over the Sahara:
Note that again this is later than the last estimate. As the satellite has gotten lower, aerodynamic drag — the wind blowing on it, tenuous as it is — has changed its orientation, creating less drag, slowing the descent.
Please note that the time is still uncertain, though now it’s only +/- 5 hours. Still, that’s a wide swath of Earth in that range, so we’re still not sure where it’ll burn up.
Check the Related posts links below for more info on the satellite, why it’s coming down, and how to read that map. Again, the danger from this is pretty minimal. You may note that the three predictions we’ve had have put re-entry over the ocean or otherwise largely uninhabited areas, and that’s not a coincidence: most of the Earth is like that! That’s why the odds of someone getting hit are so low.
I’m sure we’ll get another update or two in the next few hours, so stay tuned. You can also check the CORDS site for updates, and the NASA page as well.
Related posts:
- UARS update 2: new predicted re-entry at 00:58 UTC
- Update: satellite *might* fall on Friday at 22:00 UTC +/- 9 hours
- NASA satellite due to burn up some time in the next few days
September 23rd, 2011 at 11:40 am
Just 1/2 hour earlier and we might see the show from Colorado!
September 23rd, 2011 at 11:57 am
Someone on your g+ post commented this, and I’d like to echo it: Why specify the 16 minutes, when it’s + / – 5 hours?
September 23rd, 2011 at 12:12 pm
If the error is +/- 5 hours, why can’t it hit ANYWHERE, since the orbital period is less than 90 minutes….
September 23rd, 2011 at 12:28 pm
A calculation is done to find a value. Then, in science and engineering, it’s standard to than include the uncertainty in that calculation. It involves two different processes: doing the initial calculation and doing an error analysis to determine uncertainty in the calculated or predicted value.
September 23rd, 2011 at 12:37 pm
Someone explain to me how to calculate 3:16 uTC to EST
September 23rd, 2011 at 12:39 pm
At +1 hour it just about hits Seattle! I’ll be out tonight watching the skies around 9:15pm.
September 23rd, 2011 at 1:24 pm
Larry – UTC is basically Greenwich time (zero meridian – but not exactly GMT for other reasons), so calculate your local time based on number of time zones away you are from Greenwich. It is the protocol used in many different fields to insure an identical international time standard, and avoid confusion with time zones or daylight savings time alterations. In other words, UTC time is given, and then you make the required adjustment depending on where you are.
September 23rd, 2011 at 1:26 pm
The blue and yellow lines show all possible locations within the 10 hour window, which is a huge chunk of the globe. So don’t jump on a plane to the Sahara.
September 23rd, 2011 at 1:30 pm
If any parts of this satalitte land on land, will nasa try to recover the pieces or would it be finders keeper, loser weeper?
September 23rd, 2011 at 1:30 pm
3:16 UTC is 11:16 PM EDT.
September 23rd, 2011 at 1:35 pm
Larry- 11:16 EST (EDT)
September 23rd, 2011 at 1:42 pm
The satellite is government property, so NASA has said you can’t have them
September 23rd, 2011 at 1:42 pm
Larry: To get Eastern Daylight Saving Time, you subtract 4 hours from UTC. (subtract 5 hours to get Eastern Standard Time)
Here is a nice conversion table:
http://www.dxing.com/utcgmt.htm
September 23rd, 2011 at 1:46 pm
Looking at the picture at: http://reentrynews.aero.org/1991063b.html shows that +/- 5 hours errors equals an uncertainty of where UARS will come down of about +/- 3 1/2 full earth orbits.
While South America and China are out of range of the projected path, North America, Europe, the Middle East (!!) and western Asia are all currently still in range, with Africa (somewhere around Chad) at the center of the 9/23 12:02 UTC estimate.
Nothing to do now but play out the odds that the fragments will not hit anything the U.S. considers important.
September 23rd, 2011 at 1:57 pm
Thanks fo allyou help on the UTC conversion guys!! Am in Atl, maybe I can see it drift by….
September 23rd, 2011 at 2:04 pm
Larry,
03:16 UTC = 03:16 – 4 EDT = 23:16 EDT i.e. 11:16 p.m. EDT
If you are not using Daylight Savings Time, then it will be 00:16 a.m. EST tomorrow (Saturday, September 24th)
September 23rd, 2011 at 2:12 pm
Latest advice from Harro Zimmer
Report timestamped 19:30 UTC today
1991-063B (#21701) UARS
Based on the last five – partially inhomogeneous -
ELSETs 266.5014… – 266.7449… the fresh decay
prediction:
24 September,04:19 UTC +/- 90 minutes
ascending over 39.55°N, 227.53°E
(Over the Pacific, on the way to the US West Coast,
then crossing Canada)
But I think we will possibly see an additional rev.
Harro Zimmer Berlin (Germany)
Bob(Big)
September 23rd, 2011 at 2:19 pm
Impact zone is the Sahara? Why am I seeing a remake of “The Gods Must Be Crazy” ?
September 23rd, 2011 at 2:37 pm
Am I reading the chart right and it will be over Valencia, Spain about 7 minutes before the expected re-entry? So, like around 3:09 UTC?
I’d probably see that as a ground-based observer, right? Brb, setting alarm clock!
September 23rd, 2011 at 2:58 pm
You just know there are people running pools on this…
September 23rd, 2011 at 3:35 pm
whens it coming over the uk & where? please tell me’ somebody.. anybody.
September 23rd, 2011 at 3:54 pm
@skywatcherz
UARS passed south of the UK at about 10:06 pm local time (less than an hour ago). It was in Earth’s shadow. I looked out to see if there was already an plasma glow but nothing seen. Guys in Holland and Norway did the same and saw nothing.
@ Robin B
Predictions have moved on from the Sahara. Latest estimates are based on she ditches off the west coast of Canada +- 90 mins. The ground track reaches across the Hudson Bay (see below).
See this link courtesy of Simone at digilander.libero.it
http://tinyurl.com/3hq8hg4
Bob(Big)
September 23rd, 2011 at 3:55 pm
NASA warns everyone that if they are to find any debris that they think belongs to UARS then you have to call your local police etc etc to report it and you should not touch it as it remains the property of USA!!! Finders are NOT keepers and you could well face a fine etc for keeping parts of the UARS or trying to sell them on ebay etc!!!
September 23rd, 2011 at 3:59 pm
Jimthomson: It can not hit ANYWHERE on earth even within a plus/minus 5-hour window. That’s because in one orbit (90 minutes or so) it does not pass over the entire earth. A ring that is more-or-less directly below it. Subsequent orbits pass over different places on the earth because the earth is turning under it. So very very very approximately, it would take 12 hours (1/2 an earth rotation) before it had gone over every place on earth to within say a thousand miles or so.
There is a lot more to it, including especially the angle of the orbit to the equator; I’m only trying to give you a feel for the issue; dont’ take the above too literally.
September 23rd, 2011 at 4:05 pm
This all reminds me of some commercials that ran many, many years ago for the GTE corporation (General Telephone & Electronics Corporation) about how they had satellites in space.
At the time, I rented a small house on a farm, and the only phone service available was from GTE. The service was terrible! I’d be talking to someone and the connection would be dropped…just like w/ some cell phones today. Or, you’d pick up the line and someone would be talking (it was a private line). Or, you’d hear some strangers suddenly talking when you were having a conversation.
…..So, when the commercials ran regarding GTE’s satellites, for quite a while every time I’d step outside the house or any building, I’d look up to see if one of their creations was crashing to earth and heading toward me.
September 23rd, 2011 at 4:13 pm
So the current prediction is for just south of the Big Island? Hard to tell how far south from the low res charts. Do I need to make a point of watching the southern sky at 18:16 this afternoon?
September 23rd, 2011 at 4:28 pm
I’m in Ca. Hope I get a glimps. I think it will pass to my South.
September 23rd, 2011 at 4:33 pm
By the latest prediction I’ll be able to see it if it’s 15 minutes after the predicted time. Clear skies too, which is odd here. Finger, toes, and eyes crossed. Outside looking NNW or so from a hilltop at after 2100 or so, of course it won’t happen, but it’s getting possibler.
September 23rd, 2011 at 4:50 pm
Ok..i have been doing calculations on the re_entry point, and there is a 70.82% chance it hits water…these calculations were based on hours of research determining the land/water ratio and the realization that nobody knows.
September 23rd, 2011 at 5:00 pm
TIP Reports for Object 21701, UARS, US
Report Date/Time 2011-09-23 22:43:00 GMT
Predicted Decay Time 2011-09-24 04:49:00 GMT +/- 4 Hours
Predicted Decay Location 2.9° N, 5.5° E
Direction descending
Inclination 56.9°
Revolution Number 10920
High Interest Object N
Next Report 2 Hours
That is from JSpOC.
September 23rd, 2011 at 5:32 pm
looks like it will be passing near newfoundland at 11pm, 12:30am, 2am and 3:30am local times. i will definitely be outside looking up, hoping for clear skies.
September 23rd, 2011 at 5:39 pm
Ceramicfundamentalist, if I looked up tonight, I’d drown. It’s raining pitchforks here in Pennsylvania.
Hope it stays clear and you get a good view!
September 23rd, 2011 at 5:47 pm
update…. http://elenin.paranomalo.us/2011/09/24-sep-2011-0404-utc-%C2%B1-3-hours/
September 23rd, 2011 at 7:09 pm
It’s 02:05 am British Summer Time now (GMT + 1hr) – anyone know where it is now and if it’ll be visible from the UK in the next few hours?
September 23rd, 2011 at 7:44 pm
Just watch out for that toilet seat!
September 23rd, 2011 at 7:46 pm
Any chance I could see this thing before it comes down even as a moving satellite tonight in ga. if so let me know and the direction to look.
thks for yourhelp
September 23rd, 2011 at 8:01 pm
Now they’re saying 0510 GMT +/- 2 hours. Only land areas possible now are Africa, Australia, and Canada.
September 23rd, 2011 at 8:01 pm
Starting to look pretty good for eastern Australia, though it would be daylight: http://scienceblogs.com/gregladen/2011/09/uars_update_lookin_good_austra.php
September 23rd, 2011 at 8:04 pm
Latest update: 24 SEP 2011 @ 05:10 UTC ± 2 hours
http://reentrynews.aero.org/1991063b.html
September 23rd, 2011 at 8:17 pm
Interesting.
JSpOC has different numbers:
TIP Reports for Object 21701, UARS, US
Report Date/Time 2011-09-24 01:59:00 GMT
Predicted Decay Time 2011-09-24 04:16:00 GMT +/- 2 Hours
Predicted Decay Location 30.9° N, 218.9° E
Direction ascending
Inclination 56.9°
Revolution Number 10921
High Interest Object Y
Final Report