What astronomy app are you using that will project?I use the Apple video adapter with my iPad and an LCD projector for astronomy presentations. The iPad's output is only 1024x768, but so is the projector I'm using so it's fine. Only a few programs actually support doing this though, so you'll need to check. It does work with Keynote, but I don't think even the photo viewer supports it (haven't actually checked). The adapter is only $30 at the Apple store.