"It’s me, Uranus. I have observed my moons for many years. Longer than everyone on your planet has been alive. Out of my 27 followers, I find Ariel quite interesting. Since I am incapable of looking around the planet for myself, I am trusting you and your civilization to find some groundbreaking discoveries on this moon made of water ice and silicate rock.
Some background information, I know you discovered Ariel in 1851 by a human named William Lassel and since then you have made other remarkable discoveries. Ariel is the second closest major moon to me and orbits with the same side always facing towards me. When I look over them all I wonder why you haven’t flung a space pod over here to check it out.
Ariel has a rather smooth surface, except for multiple valleys here and there. The smooth surface implies that there is some sort of geological based reason for it, otherwise the moon would be covered in craters. The valleys suggest geological activity like earthquakes. Ariel's tectonic plates have probably drifted and separated from one another making huge valleys all over the moon.
Speaking of geological activity, Ariel, out of all of my moons, has had the most recent activity. If you go we might find out what difference this moon has to others that cause it to have more recent geological activity. This could be groundbreaking and helpful for other discoveries.
I think Ariel is strange, I’d like for you to have a look at all of the things I have listed and get back to me later about everything you know and have figured out after you visit Ariel. You might find out that it has water, how other moons are formed or something completely unexpected!"