On June 30th, 1908 “something” exploded over the Tunguska region of Siberia, flattening thousands of square kilometres of forest, and unleashing a force that rivalled the most powerful nuclear weapon ever detonated. What was it? What could unleash that kind of destructive energy? And will it happen again?

It’s hard to imagine a more famous astronomer than Galileo Galilei. He’s widely recognized as the very first person to point a telescope at the skies and then study what he saw. Galileo discovered the moons of Jupiter, the phases of Venus, and much more. But it was his controversial stance on the nature of the Solar System that brought him into conflict with the church.

And now we finish our trilogy of Saturnian astronomers and missions with a look at the Dutch astronomer and mathematician, Christiaan Huygens. It was Huygens who discovered Titan, and figured out what Saturn’s rings really are, so it makes sense that a probe landing on the surface of Titan was named after him.

Another two parter, coming at you. This week we talk about the Italian astronomer, Giovanni Domenico Cassini, best known for discovering Saturn’s moons and the biggest division in Saturn’s rings. Cassini made many other important discoveries in the Solar System, and in the fields of physics and astronomy.

The Sun, Moon, stars and planets are visible to the unaided eye, and so they have been visible to astronomers since before recorded history. Some of the earliest records we do have tell us what the ancient astronomers thought about the heavens, and how they used the changing night sky in their daily lives.

Time for another action-packed double episode of Astronomy Cast. This week we focus on the Lyman Spitzer, a theoretical physicist and astronomer who worked on star formation and plasma physics. Of course, this will lead us into next week’s episode where we talk about the mission that bears his name: the Spitzer Space Telescope.

The first half of the 20th Century was a productive time for astronomy, with theorists working out much of the science that we take for granted today. One of these astronomy stars was Subrahmanyan Chandrasekhar, who determined the maximum mass of a white dwarf star.

Nicolaus Copernicus changed our understanding of the Universe when he rearranged the Solar System to put the Sun at the center, with the Earth becoming just another of the planets orbiting it. But the movement of the planets didn’t really match the theory; not until Johannes Kepler came along with his ellipses, and everything finally worked.

Many of the modern ideas in astronomy happened in just the 20th century: dark matter, the Big Bang, inflation, quasars, black holes. So many discoveries in one important century.

With our proper place in the Universe worked out, and some powerful telescopes to probe the cosmos, astronomers started making some real progress. The next few hundred years was a time of constant refinement, with astronomers discovering new planets, new moons, and developing new theories in astronomy and physics.

Now we reach time with names that many of you will be familiar: Galileo, Kepler, Copernicus. This is an age when the biggest names in astronomy used the best tools of their time to completely rearrange their understanding of the Universe, putting the Earth where it belonged – merely orbiting the Sun, and not the center of everything.

With the earliest astronomers out of the way, we now move to one of the most productive eras in astronomy; the ancient Greeks. Even though they didn’t have telescopes, the Greeks worked out the size and shape of the Earth, the distance to the Moon and Sun, and even had some accurate ideas about our place in the Universe.

We know you love a good series. This time we’re going to walk you through the history of astronomy, starting with the ancient astronomers and leading right up to the most recent discoveries. Today we’re going to start at the beginning, with the astronomers who first tried to understand the true nature of the Earth, the planets and our place in the cosmos.