[JimCarnicelli]

I'm writing a science fiction novel and trying to keep it very realistic. I would appreciate some speculation on a story concept.

The story takes place in the Kuiper Belt out past Neptune. My understanding is that "most Kuiper belt objects are composed largely of frozen volatiles (termed "ices"), such as methane, ammonia and water" (http://en.wikipedia.org/wiki/Kuiper_belt). I also know we've confirmed that at least one comet from the Kuiper Belt contains amino acids (http://www.nasa.gov/mission_pages/stardust/news/stardust_amino_acid.html).

I'm trying to visualize a hypothetical minor planet like Pluto in the Kuiper Belt composed of a rocky core, a water ice mantle, and a methane hydrate crust rich with sulfur and nitrogen. I posit that this surface gets "baked" over billions of years by solar radiation into more complex organic compounds, including amino acids. I picture the crust having a white color and the organics on the surface being like a "black tar".

Is this too much of a stretch? I welcome a speculative discussion of whether this is possible. If not directly, perhaps there are natural conditions you can suggest that might make it more plausible.

I hope you find this a  fun challenge and appreciate your input. Thank you in advance.