Stars are hot.
Really hot. Hot enough to have energy to spare for their planets. If our star wasn’t hot, we couldn’t live on Earth. And our star isn’t even particularly hot for a star. It’s a middle-aged star of low mass, so it’s relatively cool compared to other stars.
You might also notice that stars aren’t all the same color. There are redder stars and bluer stars and more whitish stars.
We know stars are hot. They’re also bright. And they’re different colors. But how does that all translate to radiation—and how can we see it? Continue reading
Everything we know about space comes from radiation.
Now wait just a moment here. That statement explains how astronomy is such a successful field of science—it’s based entirely on the information we can glean from radiation, after all. But how does that make sense?
I mean, it’s one thing to study radiation. It’s quite another thing to study matter, the “stuff” in the universe. How does one have anything to do with the other?
Well…that’s where atoms come in. Radiation does, in fact, have a lot to do with the “stuff” it comes from. And if it weren’t for that basic principle, astronomy as a science wouldn’t work.
Thankfully for astronomers, it does. So what’s the secret, then? What does radiation have to do with matter? Continue reading