In the last few weeks we’ve had many emails saying that our tour of the solar system would not be complete without a show on the asteroid belt. Your wish is our command! We talked about Mars in episode 52, and now that we’re back on track our next stop is the asteroid belt.
Ep. 54: Questions Show #6
It’s been a while, so let’s catch up with the listener questions. We’ve got some easy ones, some hard ones and probably some impossible ones. We talk about our universe as a black hole, tidal locking of planets like Uranus, colours of stars at different ages, our universe’s birthday and more.
Ep. 53: Astronomy in Science Fiction
This is a very different episode of Astronomy Cast. As we mentioned last week, Pamela recently attended the Dragon*Con science fiction convention in Atlanta, Georgia. While she was there, she participated in a special live edition of Astronomy Cast with special guest Dr. Kevin Frazier. Kevin is a NASA scientist, and the science consultant for the TV shows Battlestar Galactica and Eureka. He and Pamela work through physics and astronomy in popular science fiction. What they get right, and what they get wrong… so very wrong.
Special Episode: Panspermia
As a reward to the all the dedicated fans who completed our demographic survey, we released this special episode of Astronomy Cast. As promised, we’re now releasing this episode to all of our subscribers. Panspermia is a controversial theory that life on Earth originated… out there. Maybe it started out in a cosmic dust cloud or originated from another planet, but somehow the very first lifeforms made the trip through the vacuum of space and colonized our home planet.
Ep. 52: Mars
Today we consider Mars, the next planet in our journey through the Solar System. Apart from the Earth, it’s the most explored planet in our Solar System. Even now there are rovers crawling the surface, orbiters overhead, and a lander on its way. It’s a cold, dry desert, so why does this planet hold such fascination?
Ep. 51: Earth
Another week, another planet. This time we talk about our own home world: Earth. You might think you know the planet beneath your feet, but it’s actually one of the most interesting and dynamic places in the Solar System. Learn about our planet’s formation, weather, its changing climate, and life.
Ep. 50: Venus
Last week we talked about Mercury, so this week our planetary parade proceeds to Venus. It’s the brightest object in the sky, the hottest object in the solar system, and it’s probably one of the most deadly places to go and visit.
Ep. 49: Mercury
We’re still digging through the thousands of comments and suggestions from the listener survey but we hear your requests and suggestions, and now you get to start reaping the benefits. Today we start our survey of the solar system with Mercury. What mysteries is it hiding from us? How similar is Mercury to the other rocky planets? How much do we really know about this first rock from the Sun?
Ep. 48: Tidal Forces Across the Universe
Last week we talked about tidal forces within our solar system. This week we’re going to expand our view and encompass the entire universe. Some of the most dramatic events originate from tidal forces caused by gravity: other worlds, galaxies, black holes and even entire clusters of galaxies are under this influence.
Ep. 47: Tidal Forces
Consider the following: we’ve got tides here on Earth, the Moon only shows one face to the Earth, we’ve got volcanoes on Io, and ice geysers on Enceladus. All these phenomena originate from a common cause: the force of gravity stretching across space to tug at another world.
Ep. 46: Stellar Nurseries
We’ve discussed star formation in the past, but now we wanted to talk about the different kinds of stellar nurseries we see across the Universe. We know where our Sun came from because we can look out and see different stellar neighborhoods at every stage of development. It takes a village of gas and dust to raise a star.
Ep. 45: The Important Numbers in the Universe
This week we wanted to give you a basic physics lesson. This isn’t easy physics, this is a lesson on the basic numbers of the Universe. Each of these numbers define a key aspect of our Universe. If they had different values, the Universe would be a changed place, and life here on Earth would never have arisen.
Listener Survey
Thank you for your interest in the survey, but we have completed gathering data. If you would like to see the results of this survey, check out our paper in Communicating Astronomy with the Public
It’s time to answer questions again, but this time we hope that you’ll take a minute and answer ours. We’ve written a brief survey that we hope you’ll take a minute to fill out. This survey will allow us to collect some general demographic information about our audience so we can make the show even better. We promise it doesn’t even ask your email address – and, if you fill it out, we’ll give you a link to a special, full-length episode that does not appear on our feed.
So please, please – do us a favour, and fill out our listener survey
Ep. 44: Einstein's Theory of General Relativity
If you remember way back to Episode 9, we covered Einstein’s Theory of Special Relativity. Well, that’s only half of the relativity picture. The great scientist made an even more profound impact on physics with his theory of general relativity, replacing Newton with a better model for gravity.
Ep. 43: Questions Show #5
It’s time to answer the questions again. And this time we’ve got some doozies. Is the Universe rotating? Is space something, or is it nothing? Is dark energy evenly distributed? What would happen if an astronaut went out the airlock, without a spacesuit. Want to know the answers? Well, you’ve got to listen.
Ep. 42: Magnetism Everywhere
You probably don’t realise it, but magnetic fields are everywhere. We’re not talking about the magnets in your speakers, your electronic equipment or on the fridge door. We’re talking about the gigantic magnetic fields that surround planets, stars, galaxies and some of the most exotic objects in the Universe.
Ep. 41: The Rise of the Supertelescopes
The last decade has been the golden age of astronomy, with new observatories and space telescopes pushing out our understanding of the Universe. We can see billions of light years away, watch dynamic events unfold in almost real-time, and see into every corner of the electromagnetic spectrum. Just you wait: things will only get better. Here come the supertelescopes!
Ep. 40: American Astronomical Society Meeting, May 2007
Once again, Pamela does her duty as an astronomer and joins her colleagues at the American Astronomical Society’s meeting, held in May, 2007 on Honolulu, Hawaii. With all that sand, surf and sun, how did anyone get any science done? Pamela tracked down the interesting stories, and brought them back so we could analyze them.
Ep. 39: Astrology and UFOs
While Pamela’s away at the American Astronomical Society meeting, we brought in a special guest to help debunk some of the pseudoscience that people mistake for astronomy. Dr Steven Novella from the Skeptic’s Guide to the Universe gets to the bottom of astrology and UFOs, and why they’re not real science.
Ep. 38: Neutron Stars and their Exotic Cousins
Huge stars become black holes, and small stars become white dwarfs. But medium-sized stars can become neutron stars; exotic objects that overcome the nuclear force holding protons and electrons apart. What was once the size of a star is compressed down to only a few dozen kilometres across.
Ep. 37: Gravitational Lensing
Astronomers are always trying to get their hands on bigger and more powerful telescopes. But the most powerful telescopes in the Universe are completely natural, and the size of a galaxy cluster. When you use the gravity of a galaxy as a lens, you can peer right back to the edges of the observable Universe.
Ep. 36: Gamma-Ray Bursts
Gamma ray bursts are the most powerful explosions in the Universe, releasing more energy in a few seconds than our Sun will put out in its lifetime. It’s only been in the last few years that astronomers are finally starting to unravel the cataclysmic events that cause these energetic explosions.
Ep. 35: Questions Show #4
We know there’s matter, and we know there’s anti-matter. If there’s dark matter, is there an anti-dark matter? How come gravity can escape from a black hole? Do black holes capture dark matter? Can a moon have a moon? Can a planet have two stars? If you’ve had any of these questions, you’ll want to listen to this week’s show.
Ep. 34: Discovering Another Earth
What a week! Astronomers announced the discovery of an Earth-sized planet orbiting the nearby star Gliese 581. We talk about the technique used to discover the planet, the possibilities of finding even smaller planets, and what the future holds for finding another Earth.
Correction: At the beginning of the show, Pamela says that Gliese 581c is estimated to have a mass of no more than 5.6 solar masses. The actual mass limit is estimated to be no more than 5.6 Earth masses. We are very sorry for the mistake. -Rebecca
Ep. 33: Choosing and Using a Telescope
Buying your first telescope can be a nerve-wracking experience filled with buyer’s remorse. This week we discuss the basics of purchasing your first binoculars and telescope. What to look for, how to clean older equipment, and how to use it for the first time. Let’s make sure your first investment in this wonderful hobby is money well-spent.