strange lights

I took some photos two nights ago at Everest Base Camp (yayaya, I'll get to that later) and could use some help identifying just what I took photos of. 

After watching the sunset over the mountain, the rest of the group and I had a late supper and headed to bed around 10:30. As I walked across the courtyard to my guest room, I had a look up and decided that seeing a clear night sky from over 5,000m was not an opportunity to be missed, and grabbed my tripod.

The camera was pointed pretty well straight up, just slightly east over Rongbuk Monastery, with a shutter speed of 30 seconds when it recorded this unedited image:

 IMG 6414

IMG 6414

See that not-so-little green thing? Here's a close-up, and then the same image with an exposure increase of 2 stops. 

 6414 a

6414 a

 +2EV

+2EV

Ok.

So, that's weird. Can't see those shapes when just looking at the sky. Better take another one to see if it was a camera malfunction or something.

 IMG 6415 , still there

IMG 6415 , still there

 6415 b

6415 b

 compared to the greeen blob in 6414 a

compared to the greeen blob in 6414 a

 6415 a: looking closer, this star doesn't look right either. a satellite maybe?

6415 a: looking closer, this star doesn't look right either. a satellite maybe?

The shapes showed up on those two images, and then no others, with the camera in the same position and settings left the same. There were a lot of "WTF"s thrown around between myself and the two other tour companions out with me, and nobody I've showed the images to has yet been able to tell me what's up.

So, internet, I'm turning to you. What's the green shape? How can it register in the images as brighter than the stars around it, yet be invisible to our naked eyes? What's the deal with the star that only seems to shine upwards? The rainbow... "disc"? I'm sure there's some simple explanation, but the wondering is killing me.