Thursday, August 18, 2016

Meteor or Satellite?

There is story about attempt to make photos of meteors. These photos were done April 13, 2016 about 5 a.m. When I saw first photo I was very happy that I this steak which looks like meteor. Direction on first view was from Perseid radiant and it was very close to Andromeda galaxy

Andromeda galaxy and meteor-satellite steak during Perseid meteor show April 2016 - photo 2
Canon 60Da, EF16-35mm f/2.8L II USM lens, ISO-6400, f/3.5, 90 sec.

I found that on previous photo I saw another steak. Fantastic!

Andromeda galaxy and meteor-satellite steak during Perseid meteor show April 2016 - photo 1
Canon 60Da, EF16-35mm f/2.8L II USM lens, ISO-6400, f/3.5, 120 sec.

But after that I recognize that both about same location and on the same line, but looks like have opposite directions! I combine both photos in one.

Andromeda galaxy and meteor-satellite steak during Perseid meteor show April 2016  - two photos
Probability that this is one meteor I think about zero. Difference between these two photos about one second and in this case meteor would be very slow. Probability that there are two meteors also very small. Definitely such situation would look very strange.


After that I googled if somebody had before such photos and can explain it. Immediately got idea that it can be Iridium satellite. When I asked this question on  astronomy forum http://www.astronomyforum.net/ and immediately received recommendation to check http://www.heavens-above.com/ website for Iridium satellites at this time. Actually it was one at about this time!,  but orbit was projected to Orion constellation from my location.

Iridium Flare

So continue to search if this is bright satellite. Havens-above web site also have this data. There were a lot of satellite so I got problem with calibration of EXIF DateTimeOriginal values the photos. I did couple of photos of computer time and http://www.time.gov/ time and compare with DateTimeOriginal. Difference about 1 hour (58 min) looks like camera not using summer time. After that I founded two satellites which most close to this time and orbit.

IRS-P2 Rocket

Cosmos 2292


One actually was in opposite direction (IRS-P2 Rocket) other in right direction and really on very close line and right direction (Cosmos 2292). But my calculation time is 4:57 a.m. - difference about 3 minutes. Probably camera clock not stable or not using start time or it can be other not so bright satellite or something other. Could not prove that these sky steaks is satellite but I believe it is most probable explanation. I added link in my blog to  http://www.heavens-above.com/   website – really amazing and very useful data. Hope my story was interesting and help other in such situation