Astronomers measure the brightness of stars as magnitude. But this brightness depends on the distance to the star as well as the total amount of energy it’s pumping out into space. And from our vantage point here on Earth, appearances can be deceiving.

Astronomers have been cataloging star positions for thousands of years, from the first calculations made by Hipparchus, to the more recent star catalogs made by the spacecraft named after him. This is astrometry; another way to find our place in the Universe.

Why are some objects in the Solar System bright while others are dim? Much of an object’s brightness is caused by its albedo, or how well it reflects radiation from the Sun. If you want to know how big a distant moon, comet, or asteroid is, you’ve got to know its albedo.

We survived our first group of mysteries, so now we move onto our second set of stuff of amazing Milky Way mysteries. How many spiral arms does our galaxy have, and why does everything keep dying every 60 million years or so?

We’ve wrapped up our Solar System mysteries and now we move onto the Milky Way mysteries, and the some of the general mysteries of galaxies. From blue stragglers to Eta Carinae… what’s going on?

Even in ancient times, astronomers realized there was something different about the planets – they move! The movement of the planets and their moons are governed by gravity. And as we all know, gravity can do some funny things.

This is going to be one of those weeks where we tackle something you’re mentally avoiding. You know all those astronomical terms, like alt-azimuth, right ascension and declination, arc seconds and arc minutes? Of course not, your mind has blocked them out. Today we’re going explain them, so you don’t need to avoid them any more. Soon, you’ll be ready to find anything in the cosmos.

Last week we talked about Fermi the man, now we’re going to talk about Fermi the space telescope. That’s right, Enrico Fermi made such an impact in the astronomy and physics community that he got a space telescope named after him. Let’s take a look at what this mission will do, and its discoveries so far.

Astronomy is one of the scientific fields that have been completely shaken up by new media. The Internet has enabled communication between researchers in a dramatic new way, creating new collaborations, removing obstacles, and drawing in an army of enthusiastic volunteers to help with research. Let’s take a look at how new media is helping change astronomy, and how you can get involved.

For those non-scientists trying to get their original ideas accepted by the scientific community, you’ve got to have thick skin. It might seem like there’s a vast conspiracy, or a general attitude that drives away original, but unorthodox ideas. But that’s not true, the reality is that great ideas in science come from everywhere, even amateurs. In this episode we’ll help you understand what scientists will be looking for, and the best ways to be taken seriously.

Have you ever wondered how astronomers do their research? How do they go from idea or question, to gathering their data, to publishing the research. What are all the hoops they have to jump through, the paperwork to fill out, and the cool toys they get to use along the way?

And now we reach the end of our tour through the electromagnetic spectrum. Last stop… gamma rays. These are the most energetic photons in the Universe, boosted up to incredible energies in the most violent places in the Universe. Gamma rays are tricky to catch, but they can reveal the most dramatic events in the Universe.