How To Find Out More About The Universe Beyond Our Solar System
For molecules, you look in a region of the spectrum called
Well that's more difficult, of course. With the solar system, we can explore with probes, beyond that, at the minute and for the foreseeable future, we just have to look. But we can build some pretty impressive telescopes! And the sensitivity of these things is really quite impressive. For molecules, you look in a region of the spectrum, called the submillimeter, it's like very short wave radio. And you know this, if you think about it, because microwaves work, kitchen microwaves work, by exciting water molecules. So that's the frequency you tune to if you want to see water in the universe. If you build a big enough telescope, then you can go a long, long way back into the history of the universe, and see these molecules, all the way back six billion years ago, or something like that. So there's plenty to be working on in the meantime, while we wait for them to invent interstellar travel.