Well...can't aruge about the "geeky" aspect of it. XD But that's what everyone on fanfiction is so you're certainy not out of place.

I haven't looked much into Astronomy myself so this was really fascinating. _ Might just spark an interest with me.

This was very sweet, and clearly you knew what you were talking about when you wrote it as far as the astronomy was concerned. ) It lended a credible atmosphere that most fanfiction writers abandon. It was well-thought out, plotwise (though simple as the plot was), and the characters felt true to themselves. Kudos for that. I have to say though-I didn't quite understand the ending. XD

Some things I noticed:

"...and wondered if humans could use radio to talk to space ships, maybe aliens in spaceships could use it to talk to people below." It starts out as a question, and turns into a declarative statement.

"While Sheska arranged for her visit out to the sleepy town, she ran to stores she didn't know existed with lists from Winry of what they'd need for it that had to be found in the city." This sentence just screams awkward phrasing. It's extremely passive, and there's some instances of noun confusion, among other small grammatical deficiences. It runs on; it's quite a mouthful.

-Use commas. Many of the sentences go on and on and on. Either separate them so their meaning becomes more coherent or use proper syntax.

-Avoid the passive voice.

Once dialogue started coming in, I didn't notice as much of the awkward phrasing.