Antoine Henri Becquerel discovered radioactivity completely by accident when he exposed a chunk of uranium to a photographic plate. This opened up a whole new field of research to uncover the source of the mysterious energy.
Another mission named after a famous physicist. This time we're looking at the Planck mission, designed to study the Cosmic Microwave Backgorund Radiation over the entire sky. Like the previous WMAP mission, this will help astronomers understand the first moments after the Big Bang.
It's time for another action-packed double episode, where we meet a man and his mission. This time around its German physicist Max Planck, considered to be the father of quantum theory - he was later granted a Nobel Prize for just that discovery. Let's take a trip back just over 100 years to learn about the man who changed our understanding of the very small.
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.
It's now believed that there's a supermassive black hole lurking at the heart of every galaxy in the Universe. These monstrous black holes can contain hundreds of millions of times the mass of our own Sun, with event horizons better than the Solar System. Show More Summary
Last week we talked about the old way navigators used to find their way around the planet; by looking at objects in the sky, and doing some tricky math. The new navigation system, of course, is the Global Positioning System, and it helps you find your spot on the planet with amazing accuracy. Let's see where the system came from, and how it works.
Last week we talked about Lyman Spitzer, and this week we’ll take a look at the orbiting observatory that bears his name: the Spitzer Space Telescope. Designed to see into the infrared spectrum, Spitzer has returned images of objects that were previously hidden to astronomers by thick shrouds of gas and dust.
When the Universe formed after the Big Bang, all we had was hydrogen. But through the process of fusion, these hydrogen atoms were crushed into heavier and heavier elements. Fusion gives us warmth and light from the Sun, destruction with fusion bombs, and might be a source of inexpensive energy. We'll also look into the controversy of cold fusion.
Now we're going to answer a question that a 4-year old might ask - what is temperature? Why are things hot and why are they cold? How hot or cold can they get? And how is this all important for astronomy?
With the discovery of a planet in the habitability zone of Gliese 581, the chances of finding life on other worlds is just getting better and better. Let’s take a look at the discoveries made at Gliese 581, provide some perspective on the real chances of life, and talk about what might come next.
Titan is Saturn’s largest moon, and the second largest moon in the Solar System. It’s unique in the Solar System as the only moon with an atmosphere. In fact, scientists think that Titan’s thick atmosphere – rich in hydrocarbons – is similar to the early Earth, and could give us clues about how life got started on our planet.
Launched in 1977, the twin Voyager spacecraft were sent to explore the outer planets: Jupiter, Saturn, Uranus and Neptune. Because of a unique alignment of the planets, Voyager 2 was the first spacecraft to ever make a close approach to Uranus and Neptune. Let’s take a look back at this amazing program, and see where the spacecraft are today.
In this special live DragonCon 2010 episode of Astronomy Cast we welcomed special guest Les Johnson, Deputy Manager for NASA’s Advanced Concepts Office to talk about the state of human space exploration. And then we opened up the show to some amazing questions from the audience. Listen to the first live show ever done with both Fraser and Pamela in the same room.
In 2006, the International Astronomical Union demoted Pluto out of the planet club. But they also started up a whole new dwarf planet club, with Pluto, Eris and the asteroid Ceres as charter members. Let’s find out what it takes to be a dwarf planet, and discuss the current membership.
We talk a lot about telescopes here on Astronomy Cast, but you really don't need any special equipment to appreciate what the night sky has to offer. Just head outside with some sky charts, maybe a planisphere, some friends and hot chocolate, and you're good to go. Let's talk about what kinds of things you can see with just your eyes.
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.
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.
Everything in the Universe is spinning. In fact, without this rotation, life on Earth wouldn't exist. We need the conservation of angular momentum to flatten out galaxies and solar systems, to make planets possible. Let's find out about the physics involved with everything that spins, and finally figure out the difference between centripetal and centrifugal force.