What Is This?

I will tell you what it is: It's part of the International Space Station as seen from Earth with a telescope. And apparently, it's very happy to see us... what is that tiny thing tingling on the P3 truss?

It's an astronaut doing his Extra-Vehicular Activity número dos during last month's Discovery mission to the orbital complex. I can help it but marvel at the scale of the station—in case you weren't amazed already by our comparison of sci-fi spaceships vs the ISS. Sure it's not the Federation's orbital base, but for primitive sentient forms without warp drives, it is pretty cool. [Astronomy Picture]

What Is This?