Hahahaha, you wish it was that simple.
RFTS and Astro are similar in some ways, but VERY different in others. Astro basically has three main sections: DSO's, calculations, and conceptual stuff.
The DSO's are kind of like in Reach, but you don't need to identify them, and they're normally sort of obscure. You need to know the defining characteristics of them, and how they relate to the overall topic of that year. The [wiki]Astronomy/DSOs[/wiki] has a table with past DSO's.
The conceptual stuff varies from year to year. It is usually a broad astronomical topic, and the test questions can go very in depth. Basically, you have to know it inside and out.
The calculations are completely new from B to C. Some of them have to deal with distance, others luminosity, temperature, redshift, etc. You have to be able to use them in a given problem. There's a formula sheet on the Astronomy Wiki
That's the gist of it. True, you have the background of RFTS, but this is like that on steroids. The good thing is, EACH partner is allowed a binder or laptop (without Internet access). It's pretty fun when you start studying it, and it's my favorite event by far, which is saying something considering how much I like Remote Sensing.
My two cents on what EAST said:
The DSOs are normally sort of obscure"? "Sort of obscure"? Half of them are so obscure that their names read like the contents of a can of alphabet soup and they don't even have a Wikipedia page.
That being said, they are very fascinating, especially the more exotic objects like blazars or the pretty ones like planetary nebulas.
While the conceptual topic does vary from year to year, all the topics are interrelated so generally it's a good idea to study everything, with an emphasis on the current year's topic.
The calculations/formulas are quite fun at times - it's very satisfying to solve a difficult problem and know that you're doing the same kind of math as real astrophysicists. However, there are a LOT of formulas, and you have to know which one(s) to use. There's a reason that Astro is the only event that lets you bring programmable calculators.
And yes, it is very much like RftS on steroids, although thankfully without any constellation identification, and the leeway on resources is awesome (I
my astro laptop...which is also my regular laptop...which is a little temperamental/broken >.>).
Yeah, most tests I've encountered require identification of DSOs.
Every test I've ever seen required DSO identification, and some of them were literally like, "What DSO is this?"