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Deorbitting satellite?

  1. Aug 28, 2007 #1
    Tonight, I saw something unlike anything else I have ever seen before. It was like a meteorite, but much slower. Instead of a streak, it was a fast moving light, much too fast to be a jet airplane. At the end of it's flight, it burned up to nothing. It was very close to 12 o'clock ahead of me and moving almost directly away from me. Does anyone know what could cause that? Is there a web site that reports expected satellite deorbits?
     
  2. jcsd
  3. Aug 28, 2007 #2

    matthyaouw

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    Maybe an iridium flare?
     
  4. Aug 28, 2007 #3

    BobG

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    Try Heavens Above. They list visible satellites which appear as a star-like light moving across the sky. They can disappear abruptly when they enter the Earth's shadow. Iridium satellites have flat, polished antenna that can reflect light just like a mirror. When they pass over at just the right angle, they can be extremely bright. Some can be seen during the day.

    CelesTrak also has satellite two-line elements for a lot of satellites and debris, but you have to calculate your own visibilities.

    The Visual Satellite Observer includes links to sources where you can get info on predicted and observed satellite decays. Predicting when a dead satellite or rocket body re-enters the atmosphere is very much an approximation. Afterwards, you can compare your observations of a possible decay to the actual decay time.
     
  5. Aug 28, 2007 #4
    Thanks for the links Bobg. Apparently, there was no expectation of an iridium flare in this area tonight. One of the links had a link to a site called seesat and I will try to contact them and find out if there is any information about what I saw.
     
  6. Aug 28, 2007 #5

    russ_watters

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    Did it actually appear to break apart as it moved?
     
  7. Aug 28, 2007 #6

    DaveC426913

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    I do beleive that some meteorites can move fairly slowly. I've seen fireballs that travelled slowly.
     
  8. Aug 29, 2007 #7
    No, it was just a fast moving bright dot, not a streak. Just before it disappeared, it grew to about twice its former brightness.
     
  9. Aug 29, 2007 #8
    I finally figured out how to use the heavens above site. Here is the list of predicted satellites for my location last night:

    Code (Text):

    Satellite                 Start         End
    Name                     Time         Time
    Cosmos 1844 Rocket 19:57:22   20:08:26
    Cosmos 2082 Rocket 20:01:57   20:07:37
    Helios 1B rocket       21:03:31   21:06:35
    Envisat                   22:21:49   22:21:49
     
    The first two of these are at about the right time, but they lasted way too long. What I saw lasted roughly 3 seconds. It seems to me that it was too fast for a satellite so it must have been a slow moving meteorite. However, compared to any meteorite I have seen, and I have seen about a hundred or so, this was very slow. As I said, it was a moving dot, not a streak.

    Edit: how can I line up the text in the chart?
     
  10. Aug 29, 2007 #9

    George Jones

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    Line it up in Notepad, and then paste in into the post.

    Code (Text):

    Satellite                 Start         End
    Name                      Time          Time
    Cosmos 1844 Rocket        19:57:22   20:08:26
    Cosmos 2082 Rocket        20:01:57   20:07:37
    Helios 1B rocket          21:03:31   21:06:35
    Envisat                   22:21:49   22:21:49
     
     
  11. Aug 29, 2007 #10
    Thanks George. Being lazy, I will just let your post do my work for me. But I will remember the technique.
     
  12. Aug 29, 2007 #11

    DaveC426913

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    This describes an Iridium flare perfectly.
     
  13. Aug 29, 2007 #12
    But the heavens above web site shows there were no iridium satellites near my location at that time. Also, it tracked about 1/4 of the sky in about 2 or 3 seconds. If you look at the table that I posted, and George Jones cleaned up, this is much too fast to be a satellite. In my opinion, your post number 6, is the more likely explaination.

    As I see it, meteor showers are caused when the planet encounters a swarm of particles that are standing relatively still in our path. These are seen as streaks. However, this was not a swarm, just an individual particle. It is possible then, that it was traveling in a path that was similar enough to our own that the relative speed was much less than the typical meteorite, and yet much more than an artificial satellite.
     
  14. Aug 29, 2007 #13
    Could be an early Aurigid.
     
  15. Aug 29, 2007 #14

    DaveC426913

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    Ah. I must have missed that part. Definitely too fast for a flare then.

    Surely a fireball. You could surf around for other witness accounts.
     
  16. Aug 29, 2007 #15

    Danger

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    Depth perception doesn't work very well for things like that, Jimmy. Since you've already stated that it was moving almost directly away from you, the only thing that you can be sure of is the angular velocity. It could have been moving very slowly and coming almost straight down, or it could have been going like greased bacon through a goose's ass at a very shallow angle.
     
  17. Aug 29, 2007 #16
    Good point. Until now, the only meteorites I have ever seen were coming at me. This one was going away. I don't know which way the earth moves in its orbit. The facts are these. I was headed in a generally western direction away from Philadelphia at roughly 8:30 p.m Tuesday evening. The object was travelling in roughly the same direction. From this information, can you tell the difference between this thing hitting us head on, and rear ending us.

    Edit. Well, not that good a point. I have never seen a meteorite as anything but a streak. This was a dot. Regardless of angle, that's slow.
     
    Last edited: Aug 29, 2007
  18. Aug 29, 2007 #17

    Danger

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    I agree that it's pretty slow, but not unheard-of. When I was about 16 or so, I was watching what I took to be an airliner (same sort of speed and size) when it suddenly exploded into nothing. I called the airport to report it, and they told me that it was a bolide (exploding meteor) that several others had seen as well.
     
  19. Aug 29, 2007 #18
    Just to be sure, I conducted the experiment you suggested using greased bacon and a goose. However, probably as anyone else who has taken the trouble to do so, I can assure you that it shed no light on the problem and irritated the goose considerably.
     
  20. Aug 29, 2007 #19

    Danger

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    :rofl::rofl::rofl:
     
  21. Aug 29, 2007 #20

    mathwonk

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    deer biting satellite?
     
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