PDA

View Full Version here: : Solar System objects


Stefan Buda
23-09-2014, 11:21 AM
No, it's not the Vogon's ships...It's the geostationary highway.
I pointed my astrograph at a random point about +6 degree declination, set the mount tracking and took 30x120sec exposures. The subs were maximum combined in DSS. Field of view is 2.7x4.1 degrees. East up.
The trails that are away from the "highway" must be decommissioned satellites.

pluto
23-09-2014, 11:39 AM
That's a great idea for an image, nice work!

Interesting how the satellites away from the "highway" are at odd inclinations too and the one on the left is obviously travelling a different speed, and therefore at a different altitude, though it's hard to tell whether it's faster or slower without knowing the orientation of the frame. I suppose all of the satellites away from 0 degree inclination would have to be on orbits significantly different from GEO to avoid collision.

Very cool :D

PeterEde
23-09-2014, 12:06 PM
Ok I was under the impression all GEO sats were stationary
And the ones we see moving are LEO

PeterEde
23-09-2014, 12:10 PM
Ah
Geostationary remains in the same position in space while the Earth rotate below.
Geosynchronous remains in the same position relative to the ground

pluto
23-09-2014, 12:12 PM
They're stationary relative to the surface of the Earth above which they orbit. In this image the mount is tracking the motion of the stars so the sats are blurred.

pluto
23-09-2014, 12:16 PM
A geosynchronous orbit is the same as a geostationary orbit if it's over the equator, as comms sats are. A geosynchronous orbit can be at any inclination or eccentricity as long as the period equals one sidereal day.

PeterEde
23-09-2014, 12:40 PM
Ok Got it
Thanks

Stefan Buda
23-09-2014, 02:31 PM
I changed geosynchronous to geostationary but I think it is just as confusing.

PeterEde
23-09-2014, 02:47 PM
It's OK Stefan. I see my error in thinking. tracking stars still means we are moving and geo synch stats move with us NOT the stars.
So I can see the Sats are still stationary relative to us but moving against the star BG

PeterEde
23-09-2014, 02:50 PM
Actually saw a tumbling/rotating sat last night as it past my scope.
bright to dim to bright to dim. Not seen one before

cometcatcher
23-09-2014, 04:24 PM
Very interesting shot. I haven't tried this yet.

Stefan Buda
23-09-2014, 09:59 PM
Peter,

The track on the left side of the image, at full resolution, shows a brightness pulsation indicating tumbling. While I was taking test exposures trying to locate the "highway" I saw a couple more that were pulsating.

SimmoW
24-09-2014, 01:07 PM
Good one Stefan. Now I'm even more paranoid at those all-seeing eyes and ears (not that I have anything to hide, sirs..)