Astronomy Cast

Ep. 98: Quasars

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 21 Jul 2008 00:00:00 GMT

Last week we talked about galaxies in general, and hinted at the most violent and energetic ones out there: active galaxies. Quasars have been a mystery for half a century; what kind of object could throw out more radiation than an entire galaxy? A black hole, it turns out, with the mass of hundreds of millions of suns performs this feat. Let's trace back the history of quasars, how they were first discovered and puzzled astronomers for so long. And let's look at what we know today.

Ep. 97: Galaxies

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 14 Jul 2008 00:00:00 GMT

This week we're going to look at some of the biggest objects in the Universe: galaxies. It was the discovery of galaxies in the early 20th century that helped astronomers realize just how big the Universe is, and how far away everything is. Let's learn how galaxies formed and how they evolve and change over time, merging with the neighbors. And what the future holds.

Ep. 96: Humans to Mars, Part 3 - Terraforming Mars

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 7 Jul 2008 00:00:00 GMT

And now we reach the third part of our trilogy on the human exploration and colonization of Mars. Humans will inevitably tire of living underground, and will want to stretch their legs, and fill their lungs with fresh air. One day, we'll contemplate the possibility of reshaping Mars to suit human life. Is it even possible? What technologies would be used, and what's the best we can hope for?

Ep. 95: Humans to Mars, Part 2 - Colonists

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 30 Jun 2008 00:00:00 GMT

After astronauts make the first tentative steps onto the surface of Mars, a big goal will be colonization of the Red Planet. The first trailblazers who try to live on Mars will have their work cut out for them, being in an environment totally hostile to life. What challenges will they face, and how might they overcome them?

Ep. 94: Humans to Mars, Part 1 - The Scientists

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 23 Jun 2008 00:00:00 GMT

We're learned about the failed missions to Mars in the past, and the current spacecraft, rovers and landers currently exploring the Red Planet. But the real prize will come when the first human sets foot on Mars. Robots are cheaper, but nothing beats having a real human being on the scene, to search for evidence of water and life.

Ep. 93: Missions to Mars, Part 2

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 16 Jun 2008 00:00:00 GMT

I know last week was a bit of a dry history lesson, but we wanted to give you some understanding of past efforts to explore Mars. Now we'll look at the missions currently in orbit, and crawling around the surface of Mars, and help you understand the science that's happening right now.

Ep. 92: Missions to Mars, Part 1

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 9 Jun 2008 00:00:00 GMT

With last month's safe arrival of the Phoenix Mars Lander, Mars enthusiasts breathed a collective sigh of relief… phew. Now it's time to search for evidence of organic molecules in the ice at Mars' north pole. But this is just the latest in a long series of missions sent to the Red Planet. Let's have a history lesson, and look back at the missions sent to Mars, successful and unsuccessful.

Ep. 91: The Search for Water on Mars

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 2 Jun 2008 00:00:00 GMT

With the successful touchdown of the Phoenix Lander, NASA is continuing its quest to find evidence of past and present water on Mars. This week we discuss the geologic history of Mars, and explain why NASA thinks the story of water on Mars is so important. And how this ties into the search for life on the Red Planet.

Ep. 90: The Scientific Method

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 26 May 2008 00:00:00 GMT

You've heard us say it 90 times: "How we know what we know." But how do we know how we know what we know? So astronomers like all scientists use the scientific method. Without the scientific method we'd probably still think the Earth is flat, only a few thousand years old and the center of the universe. But with the scientific method everything changes. From biology, to chemistry, to physics, to astronomy it is impossible to count the number of changes that have happened to human society because of changes brought about from the scientific method. In this episode we tell you about what the scientific method is, how you can use it to improve your life, and discuss why gravity isn't just a theory.

Ep. 89: Adaptive Optics

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 19 May 2008 00:00:00 GMT

Since the dawn of humanity, astronomers have wished to destroy the atmosphere. Oh sure, it's what we breathe and all, but that stupid atmosphere is always getting in the way. Since destroying the atmosphere is out of the question, astronomers have figured out how to work with it. To distort the mirror of the telescope itself though the magic of adaptive optics.

Ep. 88: The Hubble Space Telescope

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 12 May 2008 00:00:00 GMT

Our understanding of the cosmos has been revolutionized by the Hubble Space Telescope. The breathtaking familiar photos, like the Pillars of Creation, pale in comparison to the astounding amount of science data returned to Earth. Hubble's getting old, though, serviced several times already, and due for another mission later this year. Let's relive the historic observatory's amazing life so far, and see what the future holds.

Ep. 87: The End of the Universe Part 2: The End of Everything

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 5 May 2008 00:00:00 GMT

Hopefully you've all recovered from part 1 of this set, where we make you sad about the future of the humanity, the Earth, the Sun and the Solar System. But hang on, we're really going to bring you down. Today we'll look far far forward into the distant future of the Universe, at timescales that we can barely comprehend.

Ep. 86: The End of the Universe Part 1: The End of the Solar System

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 28 Apr 2008 00:00:00 GMT

This is a show we wanted to do since we started Astronomy Cast but we always thought it was too early. We wanted you to know that we're positive, happy people with enthusiasm for astronomy and the future. It's time for some sadness. It's time for a grim look to see what the future holds for the Universe. This week we stay close to home and consider the end of humanity, the Earth, the Sun, and the entire Solar System. Next week we'll extend out to the very end of the Universe.

Ep. 85: Detectors

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 21 Apr 2008 00:00:00 GMT

Our senses can only detect a fraction of the phenomena happening in the Universe. That's why scientists and engineers develop detectors, to let us see radiation and particles that we could never detect with our eyes and ears. This week we'll go through them all, so you can understand how we see what we can't see.

Ep. 84: Getting Around the Solar System

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 14 Apr 2008 00:00:00 GMT

Have you ever wondered what it takes to get a spacecraft off the Earth and into space. And how managers at NASA can actually navigate a spacecraft to another planet? And how does a gravity assist work? And how do they get them into orbit? And how do they land? So many questions…

Ep. 83: Wave Particle Duality

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 7 Apr 2008 00:00:00 GMT

Have you ever heard that photons behave like both a particle and a wave and wondered what that meant? It's true. Sometimes light acts like a wave, and other times it behaves like a little particle. It's both. This week we discuss the experiments that demonstrate this, explain how scientists figured it all out in the first place. What does wave/particle duality have to do with astronomy? Well, everything, since light is the only way astronomers can see out into the Universe.

Ep. 82: Space Junk

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 31 Mar 2008 00:00:00 GMT

We're polluting every corner of our own planet, so it only makes sense that we'll take our trashy habits out into space with us. This week we look at the myriad of ways we're messing up space, from the trash orbiting the planet to the radiation we're leaking out into space.

Ep. 81: Questions on the Shape Size and Centre of the Universe

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 24 Mar 2008 00:00:00 GMT

As predicted we got a lot of questions from people about our trilogy of shows on the size, shape and centre of the universe. Today we'll do our best to clear them all up.As always, if you're still confused drop us an email to info at astronomycast dot com.

Ep. 80: Craters

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 17 Mar 2008 00:00:00 GMT

Pamela's attending the 39th Lunar and Planetary Sciences Conference, and you know what that means: the Moon… and planets! When you think of the Moon, you think of craters. In fact, that's a big theme this week at the conference, so Pamela took it as inspiration. Here you go, the week we drove the show into a crater. Wait… there's got to be a better way to describe this.

Ep. 79: How Big is the Universe?

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 10 Mar 2008 00:00:00 GMT

We’re ready to complete our trilogy of discovery about the universe. We’ve learned that it has no center; rather everywhere is its center and nowhere. We discovered that the universe seems to be flat. It not open, it is not closed, it is flat. If that doesn’t make any sense, you need to listen to the previous show because there’s no way I could give that an explanation. So now we want to know: “How big is it?” Does it go on forever or is it finite in scale? How much of it can we see?

Ep. 78: What is the Shape of the Universe?

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 03 Mar 2008 00:00:00 GMT

Some of the biggest questions in the universe depend on its shape. Is it curved? Is it flat? Is it open? Those may not make that much sense to you, but in fact it’s very important for astronomers. So which is it? How do we know? How did we figure it out? Why does it matter?

Ep. 77: Where is the Centre of the Universe?

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 25 Feb 2008 00:00:00 GMT

There are some people – I’m not naming names – who think the universe revolves around them. In fact, for most of humankind, everybody thought that. It’s only been in the last few hundred years that scientists finally puzzled out that the Earth isn’t the centre of the universe at all. That begs the question: where is the centre?

Ep. 76: Lagrange Points

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 18 Feb 2008 00:00:00 GMT

Gravity is always pulling you down, but there are places in the solar system where gravity balances out. These are called Lagrange points and space agencies use them as stable places to put spacecraft. Nature is on to them and has already been using them for billions of years.

Student Questions: Curtis High School

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Sat, 16 Feb 2008 00:00:00 GMT

This is our second installment in our series of student questions shows and these questions come to us from Curtis High School.

Ep. 75: Stellar Populations

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 11 Feb 2008 00:00:00 GMT

After the big bang, all we had was hydrogen, a little bit of helium, and a few other trace elements. Today, we’ve a whole periodic table of elements to enjoy, from oxygen we breathe to the aluminium cans we drink from to the uranium that powers some people’s homes. How did we get from plain old hydrogen to our current diversity? It came from stars, in fact successive generations of stars.

Ep. 74: Antimatter

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 04 Feb 2008 00:00:00 GMT

Sometimes, we don’t get to decide what our show’s about. So many threads come together at the same time driving the decision for us. This is one of those situations. We’ve gotten so many questions from listeners in just the last week about antimatter that our show had just been chosen for it. You command, we obey. Let’s talk about antimatter.

Ep. 73: Questions Show #8

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 28 Jan 2008 00:00:00 GMT

We’ve been so crazy following our own whims through the universe that we’ve neglected your questions. That ends today. It’s time to dig deep into our overflowing email box to retrieve the puzzling questions our listeners have sent in.

Ep. 72: Cosmic Rays

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 21 Jan 2008 00:00:00 GMT

We’re going to return back to a long series of episodes we like to call: Radiation that Will Turn You Into a Superhero. This time we’re going to look at cosmic rays, which everyone knows made the Fantastic Four. These high-energy particles are streaming from the Sun and even intergalactic space, and do a wonderful job of destroying our DNA, giving us radiation sickness, and maybe (hopefully!) turning us into superheroes.

Ep. 71: Gravitational Waves

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 14 Jan 2008 00:00:00 GMT

When he put together his theories of relativity, Einstein made a series of predictions. Some were confirmed just a few years later, but scientists are still working to confirm others. And one of the most fascinating is the concept of gravitational waves. As massive objects move in space, they send out ripples across the Universe that actually distort the shape of matter. Experiments are in place and in the works to detect these gravitational waves as they sweep past the Earth.

Ep. 70: How to Win a Nobel Prize

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 07 Jan 2008 00:00:00 GMT

Just a couple of shows ago, we showed you how to get a career in astronomy. Now that you've got your career in astronomy, obviously the next goal is to win a Nobel prize. We're here at the American Astronomical Society meeting in Austin, which is just one tiny step that a person has to take before you get that Nobel prize. Before you get that call in the middle of the night from Sweden, you're going to need to come with an idea, do some experiments, write a paper, get published and a bunch of other stuff. This week, we'll tell you all about it.

Student Questions: Farmersburg School

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Sun, 06 Jan 2008 00:00:00 GMT

Thanks to GLAST, Astronomy Cast is now able to provide equipment to send to high school teachers who want to Pamela and Fraser to do a special questions show just for their class. We will be making this shows available on the feed on days other than Monday (that's still reserved for your regularly scheduled Astronomy Cast). This is the first one available and comes with questions from Farmersburg School.

Episode 69: The Large Hadron Collider and the Search for the Higgs-Boson

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 31 Dec 2007 00:00:00 GMT

When it was first developed, the standard model predicted a collection of particles, and thanks to more and more powerful colliders, physicsists have been able to find them all except one: the Higgs-Boson. It's an important one because it should explain how objects have mass. The European Large Hadron Collider should have the power and sensitivity to find the Higgs-Boson.

Episode 68: Globular Clusters

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 24 Dec 2007 00:00:00 GMT

This week we're going to study some of the most ancient objects in the entire Universe; globular clusters. These relics of the early Universe contain hundreds of thousands of stars, held together by their mutual gravity. Since they formed together, they give astronomers a unique way to test various theories of stellar evolution.

Episode 67: Building a Career in Astronomy

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 17 Dec 2007 00:00:00 GMT

With all the enthusiasm that’s being generated with astronomy, it’s had a bit of a strange side-effect. We’ve been causing some of our listeners to have midlife crises about their careers. We’ve had other people who just want advice – they’re moving into college for the first time and they want to direct the courses they’re going to be taking into astronomy. Some other people already have skills that are very useful and have wondered how they can help up or even change their career to be working in the field. We thought we’d try and answer everyone’s questions all at once and just run through the major career paths you can take that relate to astronomy and space, and the kinds of things you’ll need to do to actually make yourself a good candidate for that field.

Episode 66: How Amateurs can contribute to Astronomy

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 10 Dec 2007 00:00:00 GMT

Astronomy is one of the few sciences where amateurs make meaningful contributions to discoveries. Many professional researchers work hand-in-hand with teams of amateurs to make discoveries that just wouldn't be possible without this kind of collaboration. In fact, Pamela regularly relies on dedicated enthusiasts for her data on variable stars.

Episode 65: The End of Our Tour Through the Solar System

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 03 Dec 2007 00:00:00 GMT

All good things come to an end - we now find ourselves in the outer reaches of the solar system where our Sun is hard to distinguish from the other bright stars in the sky. But we're not done with the solar system, there's some stuff that's leftover. This week, we look at the outer reaches of the solar system and how it interacts with the rest of the universe.

Episode 64: Pluto and the Icy Outer Solar System

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 26 Nov 2007 00:00:00 GMT

It's been a long journey, 64 episodes, but now we're back where we began: Pluto. Last time we talked about how Pluto lost its planethood status, so we won't go over all that again. This time we're going to talk about Pluto, its moons, the Kuiper belt, and the other icy objects that inhabit the outer Solar System.

Episode 63: Neptune

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 19 Nov 2007 00:00:00 GMT

We’ve reached Neptune, the final planet in our tour through the solar system – but don’t worry! The tour’s not over, but after this week we’ll be all out of planets. Neptune has a controversial story about its discovery, some of the strongest winds in the solar system and some weird moons.

Episode 62: Uranus

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 12 Nov 2007 00:00:00 GMT

This week, we're on to the next planet in the solar system. We don't know a whole lot about this blue gas planet, but today we'll cover some of the neat stuff we do know, including it's faint rings, sideways axis of rotation and its rocky core - a first in the gas planets we've encountered so far in our tour.

Episode 61: Saturn's Moons

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 05 Nov 2007 00:00:00 GMT

We know that delaying this show one more week would be too dangerous, so here you go: Saturn's moons. These are some of the most interesting objects in the Solar System, from the spongy Hyperion, to the geysers on Enceladus, to the rainy, misty, oceany Titan. They've kept Cassini busy for years, and scientists will likely be pondering them for decades.

Episode 60: Questions on Inflation

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 29 Oct 2007 00:00:00 GMT

It's about time for a question show again, so we'll have one last interruption to our planetary tour, to deal with the questions that arose from our inflation show.So if you still don’t understand inflation, take a listen to this week's show and as always, send us your questions.

Episode 59: Saturn

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 22 Oct 2007 00:00:00 GMT

Returning to our journey through the solar system, let's voyage away from the largest planet to the second largest, Saturn. Once again, we'll break up our visit because there's lots to talk about. This week, we talk about Saturn and its famous rings. Next week, we'll discuss its many moons.

Episode 58: Inflation

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 15 Oct 2007 00:00:00 GMT

We interrupt this tour through the solar system to bring you a special show to deal with one of our most complicated subjects: the big bang. Specifically, how it's possible that the universe could have expanded faster than the speed of light. The theory is called the inflationary theory, and the evidence is mounting to support it. Einstein said that nothing can move faster than the speed of light, and yet astronomers think the universe expanded from a microscopic spec to become larger than the solar system, in a fraction of a second.

Episode 57: Jupiter's Moons

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 08 Oct 2007 00:00:00 GMT

Last week we talked about Jupiter and we could sense right away it would be too much to handle. This week, we'll talk about Jupiter's moons - how many are there? What makes them so interesting? Is it true that the most likely place in the solar system to find life (other than Earth) is actually on one of Jupiter's moons? Hang on tight. We're going to cover a lot.

Episode 56: Jupiter

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 01 Oct 2007 00:00:00 GMT

Last week we talked about rubble, this week we're going to dig into the largest planet in the Solar System: Jupiter, but will it all just be hot gas? There's so much to talk about, we've decided to break this up into two shows. This week we're going to just talk about Jupiter, and then next week, we're going to cover its moons.

Episode 55: The Asteroid Belt

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 24 Sep 2007 00:00:00 GMT

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.

Episode 54: Questions Show #6

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 17 Sep 2007 00:00:00 GMT

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.

Episode 53: Astronomy in Science Fiction

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 10 Sep 2007 00:00:00 GMT

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

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Tue, 04 Sep 2007 00:00:00 GMT

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.

Episode 52: Mars

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 03 Sep 2007 00:00:00 GMT

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?

Episode 51: Earth

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 27 Aug 2007 00:00:00 GMT

So, another week, another planet. Last week we discussed Venus, and that means this week it is time for our home planet - Earth.

Episode 50: Venus

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 20 Aug 2007 00:00:00 GMT

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.

Episode 49: Mercury

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 13 Aug 2007 00:00:00 GMT

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?

Episode 48: Tidal Forces Across the Universe

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 06 Aug 2007 00:00:00 GMT

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.

Episode 47: Tidal Forces

info@astronomycast.com (Fraser Cain & Dr. Pamela Gay) — Mon, 30 Jul 2007 00:00:00 GMT

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.