The sudden brightening of Comet McNaught has reminded us what a treat it can be to see a comet with the unaided eye. A diffuse ball with a long tail stretching across the sky. There’s nothing else in the night sky that can compare to a bright comet. But what are these objects, where do they come from, and what can they tell us about the formation of the Solar System?
Special Alert: Go See Comet McNaught
There’s a big bright comet visible in the sky right now. Listen to this special alert, and then go outside right at sunset to see Comet McNaught with your very own eyes. You’ve got to move quickly, as it’ll be lost in the glare of the Sun. Don’t worry, it’ll reappear shortly, and could be one of the brightest comets in recent history.
Ep. 18: Black Holes Big and Small
We’re finally ready to deal with the topic you’ve all been waiting for: Schwarzschild swirlers, Chandrasekhar crushers, ol’ matter manglers, sucking singularities… you might know them as black holes. Join as as we examine how black holes form, what they consume, and just how massive they can get.
Ep. 17: Where does the Moon Come From?
We take the Moon for granted, but its effect on the Earth is very important; possibly even critical for the formation of life. But where did it come from? Did the Earth and Moon form together? Or did the Earth capture a wayward Moon? Or was there a more catastrophic cause to this lunar mystery?
Ep. 16: Across the Electromagnetic Spectrum
We see the Universe in visible light with our photon detecting eyes. We can feel infrared heat with our photon detecting hands, and we get sunburns with our ultraviolet photon detecting skin (ouch). But there’s a whole spectrum of photons out there, from radio waves to gamma rays that astronomers use to understand the Universe. It’s time to see the whole picture.
Ep. 15: Questions Show #1
We finally get organized enough deal with several listener questions: isn’t dark matter just regular stuff we can’t see? how can parts of the Universe be expanding faster than the speed of light? what will Betelgeuse look like when it explodes as a supernova? what’s the speed of gravity? All these and more questions are answered.
Ep. 14: We're all Made of Supernovae
No more suspense. This week we blow the biggest stars up. Kaboom. Want more details? Then you’ve got to listen.
Ep. 13: Where Do Stars Go When They Die?
We’ve celebrated the birth of new stars, but the stellar lifecycle doesn’t end there. Stars like our Sun will spend billions of years fusing together hydrogen and pumping out energy. And when the fuel runs out, their death is as interesting as their birth. This week Fraser and Pamela trace out this stellar evolution, and explain what the future holds for stars, large and small.
Ep. 12: Where Do Baby Stars Come From?
Most parents have had that uncomfortable conversation with their children at some point. Mommy, Daddy, where do stars come from? You hem and haw, mumble a few words about angular momentum and primordial hydrogen and then cleverly change the subject. Well, you don’t have to
avoid the subject any longer. Pamela and Fraser describe formation of stars, large and small, in a tasteful manner, using only understandable and scientific language.
iPod Issues Fix
Several of you have reported problems getting your iPods to play our show and other podcasts. Unfortunately, the latest version of iTunes has some new features that are making iPods behave oddly when they try to play podcasts that aren’t in stereo. To fix this problem, go into the Settings menu of your iPod and set EQ to off. Sorry for the inconvenience.
Ep. 10: Measuring Distance in the Universe
You hear distances all the time in astronomy. This star is 10 light-years away; that galaxy is 50 million light-years away; that Big Bang over there happened 13.7 billion years ago. But how did astronomers actually figure out how far away everything is? It’s not a single measuring stick. Instead, astronomers have built up a series of overlapping measuring tools (yes, we’re calling supernovae and variable stars “tools”), which take us from right around the corner to very ends of the Universe. Get out your ruler… no, the bigger one… never mind… just listen.
Ep. 9: Einstein's Theory of Special Relativity
It’s all relative. How many times have you heard that? Well, when you’re traveling close to the speed of light, everything really is relative; especially the passage of time. This week, Fraser and Pamela give you the skinny on Einstein’s Special Theory of Relativity. After listening to a few thought experiments, you too should be able to wrap your head around this amazing theory.
Ep. 8: Meteor Showers. Yes, the sky is falling.
Dress warmly, gather some friends and family, and head outside to watch sand burn in the upper atmosphere. There’s nothing like a good meteor shower. Fraser and Pamela explain this beautiful phenomenon: what causes them, the best storms and showers to watch for, and different types of meteors you might see.
Ep. 7: Getting Started in Amateur Astronomy
Got your eye on that $40 telescope at Walmart? Wait, hear us out first! Fraser and Pamela discuss strategies for getting into amateur astronomy – one of the most worthwhile hobbies out there. We discuss what gear to get, where to look, and how to meet up with other astronomy enthusiasts.
Ep. 6: More Evidence for the Big Bang
Last week’s episode started out with a bang… a Big Bang. This week we continue our discussion into the beginning of everything. We present three additional lines of evidence that have led astronomers to the conclusion that our Universe started out as a singularity 13.7 billion years ago, and has been expanding ever since.
Ep. 5: The Big Bang and Cosmic Microwave Background
As a tribute to John Mather and George Smoot, the two leaders of the Cosmic Microwave Background Explorer (COBE) satellite science team, and winners of this year’s Nobel Prize for Physics, we head back to the beginning of everything… the Big Bang. Follow as we trace the Big Bang’s discovery, and one of the most important lines of evidence: the cosmic microwave background radiation which was predicted by theory and then discovered by accident.
Ep. 4: The Search for Dark Matter
Dark matter . . . What is it? Nobody knows for sure, but it’s definitely there. Or maybe it’s not there, and we just need some redefinition of gravity at vast scales. Join Fraser and Pamela as we discuss the discovery, detection, and possible explanations of dark matter.
Ep. 3: Hot Jupiters and Pulsar Planets
You have lived on the Earth all your life, so you’d think you know plenty about planets. As usual though, the Universe is stranger than we assume, and the planets orbiting other stars defy our expectations. Gigantic super-Jupiters whirling around their parent stars every couple of days; fluffy planets with the density of cork; and Earth-sized fragments of exploded stars circling pulsars. Join us as we round up the latest batch of bizarro worlds.
Ep. 2: In Search of Other Worlds
Look down at your feet. There… you’re looking at a planet. Now look into the night sky and you should be able to spot a few more. After that, spotting additional planets becomes really hard, especially when you’re trying to find them orbiting other stars. This week we discuss the techniques astronomers use to locate distant worlds.
Ep. 1: Pluto's Planetary Identity Crisis
Pluto. It’s a planet, then it’s not. This week we review Pluto’s history, from discovery to demotion by the International Astronomical Union. Learn the 3 characteristics that make up a planet, and why Pluto now fails to make the grade.
Welcome to Astronomy Cast!
Astronomy Cast offers you a fact based journey through the cosmos. Each week Fraser Cain (Universe Today) and Dr. Pamela Gay (CosmoQuestX / Slacker Astronomy) take on topics ranging from the nearby planets to ubiquitous dark matter. Your questions can guide our discussion! Write us at questions@astronomycast.com and tell us what questions you want answered.