Aug 152015
 

I used to use J-track to look up what was overhead, but it doesn’t seem to work anymore due to some Java security issue. Can anybody tell me what just passed overhead of here (northern Utah) at about 10:10 PM Mountain time, jsut a few minutes ago? It was on what appeared to be a more-or-less polar orbit, heading straight north, exhibiting some most remarkable “flashing.” I’ve been watching satellites out here for a decade now and have seen a number of different behaviors, but this one was very anomalous: invisibly dark most of the time, it would flare up to Venus-bright for just a split second (and I mean *very* quickly), then go dark again. A random couple of second later it would do it again, and again…

I’ve seen steady light from satellites (including what must have been the ISS heading easterly, just a minute or three after the other satellite), and I’ve seen  satellites that flare up for a second and down again, but this is the first one that “blinked” this quickly and this brightly.

Any heap appreciated.

 Posted by at 9:22 pm
  • Sejones
  • Heavens-Above.com has a “history” feature: http://heavens-above.com/AllSats.aspx?lat=41.6938&lng=-112.2941&loc=Thatcher&alt=1320&tz=MST

    Name, Magnitude Start(Time, Alt,Az.), Highest Point(Time, Alt,Az.), End(Time, Alt,Az.)

    FENGYUN 3A 4.0 21:59:49 10°S 22:05:07 63°W 22:10:26 10°NNW
    Cosmos 2278 Rocket 2.7 21:59:54 10°SW 22:05:29 63°WNW 22:11:07 10°NNE
    Cosmos 2082 Rocket 2.3 22:03:56 10°NNW 22:09:32 62°ENE 22:12:19 30°SE
    MetOp-B4.2 22:09:27 28°SE 22:12:16 64°ENE 22:17:35 10°N
    ALOS 3.222:08:17 10°S 22:12:47 46°W 22:17:17 10°NNW
    ISS -3.222:09:59 10°NW 22:13:13 61°NNE 22:13:44 51°ENE
    Hope that helps!

  • se jones

    I like to use sat flairs as a stellar distance reality check when I’m out at night when camping with people.

    Decades of bad TV & movie sci-fi has left the average person with the impression that if you scaled the solar system down to say, the size of a football field, the galaxy is about the size of the Mediterranean, so Kirk & pals can cruise around and sort of bump into aliens on a weekly basis.

    But, when I tell them if we scaled the sun down to the size of a cantaloupe, the solar system would be about 3 or 4 city blocks across, making the nearest star – – – gulp – – 3000 miles away (from Seattle to Miami). They are usually incredulous.

    I then relay the story of how the first crude estimate of the distance to the stars was using a disk with various holes drilled in it (Hipparchus as I recall). He held up the disk to the sun, then by looking at the brightness of the tiny speck of sunlight shining through the hole, guess that the stars were about the same size and brightness as the sun, did the math of the ratio of the hole in the disk, to the actual size of the sun’s disk in the sky, he came up with a remarkable “order of magnitude” distance to the stars way before parallax measurement was used.

    By the same token, when we see the sun reflecting off a shiny surface on a satellite, we can compare that brightness to the brightness of the stars. We can assume the spectacular reflection of the sun on the satellite structure is about eight or ten inches around, assume the satellite is about 200 miles away, then do the math ratio and – – you get a crude estimate of the distance to the stars.
    They be far.
    Good realty check for those who don’t grasp the enormity of the galaxy.

    • publiusr

      Makes you wish our system was passing through a cluster–like from NIGHTFALL

  • xvdougl

    Speaking of Heavens-above (which is a really great site) anyone have any luck with the Iridium flare function? I think I got it to work once.