2006-07-02 - Chula Vista campground parking lot, Mt. Pinos, CA - Light

Two white llights accelerating and changing directions in M31 binocular FOV observed from Mt. Pinos

Was observing and photographing all night at my usual dark-sky haunt on top of Mt. Pinos 8350 feet altitude in the Chula Vista campground parking lot. About a dozen other astronomers were observing or doing astrophotography.

I was using my 15 X 70 binoculars (4.3 degrees TFOV) on top of my monopod/mount and was looking at M31, the Andromenda Galaxy, when I noticed two points of light enter the field of vision. They had no apparent diameter, similar to the field stars in the FOV. I estimate their magnitude at about 8 or 9. They entered the FOV from the left (north-east) with one light leading the other by about half a degree. At first they were almost on the same track, maybe just slightly offset. Then the second following light accelerated and pulled abreast and below the first light.

At this time they were basically parallel with each other and about half a degree distance apart. I estimate their speed at about a half arc-minute per second. They stayed like that for about 2-3 seconds and were just below the galaxy.

Then the lower, second light accelerated slightly ahead of the first and then their trajectories started diverging with the lower light rapidly turning downward out of the FOV (eastward) while the top light started slowly rising (westward) out of the FOV. Needless to say I was amazed at what I was seeing and was yelling to the rest of the crowd (some with binoculars) to quickly look at M31. I was in a quandary as to which light to follow and I was wildly swinging from one diverging light to the other until I lost both.

Since I has lost them in the binoculars, I tried to see if I could see something with just my eyes. I could not see anything near M31. Limiting magnitude that night was the typical 6.1 for this location. I am familiar with the behaviour of satellites as this is a very common sight at Pinos with the ISS, Intelsat, HST and Iridium constellation commonly visible. It was not an Iridium satellite since the lights maintained their magnitude at all times with no dimming or brightening. It was not any of the common satellites who usually have a much larger visual magnitude and always maintain the same speed and direction across the sky. The lights had a much greater speed than other satellites that I have observed. I have never witnessed a satellite changing accelerations and directions. There were only the single points of white light.

I don't think they could have been extreme high altitude aircraft since I would think the only visible light from such aircraft would be their exhaust jet which at my observing location would have have been oblique to me. Also if this was common high altitude aircraft then their speeds would have had to be very great at this long distance to account for my observations of extreme accelerations. At this time I don't know what I observed. Experimental military spacecraft or vehicles of LGM, I don't know, first time I saw anything out of the ordinary in the night sky. At least I have a story to tell now when the conversation turns to observed wierdness.