Comets can spend billions of years out in the Oort Cloud, and then a few brief moments of terror orbiting the Sun. These are the sun grazers. Some survive their journey, and flare up to become the brightest comets in history. Others won’t survive their first, and only encounter with the Sun.
Ep. 320: Layers of the Sun
Our Sun isn’t just a terrifying ball of white hot plasma, it’s actually a lot more complex. It’s got layers. And today, we’re going to peel back those layers and learn about the Sun – from the inside out.
Ep. 311: Sound
Shhhh, shhh. You can stop screaming. That’s because nobody can hear you … in space. But why not? How does sound work here on Earth, and what would it sound like on other planets?
Ep. 308: Climate Change
When it comes to carbon dioxide, just a little goes a long way to warming the planet. Unfortunately, we’ve been dumping vast amounts into the atmosphere, recently passing 400 parts per million. Let’s look at the science of the greenhouse effect, and how it’s impacting our global climate.
Ep. 307: The Pacific Ring of Fire
The Pacific Ring of Fire wraps around the Pacific Ocean, including countries like Japan, Canada, New Zealand and Chile. And the inhabitants within those countries are prone to… oh… killer earthquakes, volcanoes and tsunamis. Let’s chat about the history of this region and the kinds of risks they face.
Ep. 302: Planetary Motion in the Sky
Even the ancient astronomers knew there was something different about the planets. Unlike the rest of the stars, the planets move across the sky, backwards and forwards, round and round. It wasn’t until Copernicus that we finally had a modern notion of what exactly is going on.
Ep. 301: Planetary Migration
We’re so familiar with the current configuration of the planets in the Solar System, but did the planets always orbit in this way? Did they form further out and then migrate inward to their current positions? And what about other star systems out there?
Ep: 290 Failed Stars
If you get enough hydrogen together in one place, gravity pulls it together to the point that the temperature and pressures are enough for fusion to occur. This is a star. But what happens when you don’t have quite enough hydrogen? Then you get a failed star, like a gas giant planet or a brown dwarf.
Ep. 244: Io
If you want to see one of the strangest places in the Solar System, look no further than Io, Jupiter’s inner Galilean moon. The immense tidal forces from Jupiter keep the moon hotter than hot, with huge volcanoes blasting lava hundreds of kilometres into space.
Ep. 242: Torino Scale
When you hear of a looming asteroid strike, do you wonder what to do? Should you go into your underground bunker, evacuate the state, or leave the planet? Fortunately, astronomers have developed the Torino Scale – a handy measurement that incorporates both the risk of a strike with the amount of devastation.
Ep. 238: Solar Activity
The Sun looks like a harmless burning ball of fire in the sky: warm, life-giving and forever unchanging. But we know better, don’t we. It’s really a massive ball of churning hydrogen plasma, encased in twisting magnetic field lines, speckled with sunspots, and constantly disgorging vast plumes of radiation and charged particles. The Sun is very active indeed.
Ep. 237: Spooky Sounds From Space
To help you out with your halloween parties, we’ve collected together the spooky sounds of space. Every piece of audio we’re about to play might sound like it comes from a terrifying nightmare dimension, but it’s really just a natural space phenomena.
Ep. 226: Weather
How’s the weather? Maybe a better question is… why’s the weather? What is it about planets and their atmospheres that create weather systems. What have planetary scientists learned about our Earth’s weather, and how does this relate to other planets in the Solar System. What is the most extreme weather we know of?
Ep. 225: Ice in Space
A huge part of the Solar System is just made of ice. There are comets, rings, moons and even dwarf planets. Where did all this ice come from, and what impact (pardon the pun) has it had for life on Earth?
Ep. 223: The Transit of Venus
Since the planet Venus is closer in to the Sun than Earth, there are rare opportunities to see it pass directly in front of our parent star. This is known as a planetary transit, and thanks to the geometry of the Earth and Venus, they only happen a couple of times a century. The transits of Venus have been used by astronomers to unlock the scale of the Solar System, and there’s another one just around the corner.
Ep. 220: Mass Extinction Events
The Earth seems like a safe place, most of the time. But we have evidence of terrible catastrophes in the ancient past. Times when almost all life on Earth was wiped out in a geologic instant. What could have caused so much devastation? And will something like this happen again?
Ep. 203: Europa
Europa is the smallest of the Jovian satellites, but it might be one of the most exciting spots in the Solar System. When NASA’s Voyager spacecraft flew past the moon, they discovered huge cracks in its icy surface. Is it possible that Europa has a huge ocean of liquid water, and maybe even life? This is a world that needs more investigation.
Ep. 202: The Planets at Gliese 581
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.
Ep. 201: Titan
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.
Ep. 195: Planetary Rings
Saturn is best known for its rings. This huge and beautiful ring system is easy to spot in even the smallest backyard telescope, so you can imagine they were a surprise when Galileo first noticed them. But astronomers have gone on to find rings around the other gas giant worlds in the Solar System – the differences are surprising.
Ep. 194: Dwarf Planets
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.
Ep. 175: Mysteries of the Solar System, Part 2
Apparently this is at least a 2 part series. This week we continue examining some of the baffling mysteries of the Solar System, where we fill your head with more questions than answers. Sometimes we’ve just got to share the enjoyment of not knowing the answer.
Ep. 174: Mysteries of the Solar System, Part 1
We know a lot about our Solar System, but there’s an awful lot that’s a complete and total mystery. Today we’re going to begin a series of unknown length examining some of these mysteries, and explain the best theories astronomers have so far.
Ep. 159: Planet X
Astronomers have been searching for the mysterious Planet X for hundreds of years. It was the search for a theoretical planet beyond Uranus that turned up Neptune, and then again for Pluto. And even now there are some astronomers who think there’s a more distant planet out there. Oh, and there are a bunch of pseudoscience cranks trying to freak people out about the end of the world. Don’t worry, we’ll make time for them too, but first let’s start with some real science.
Ep. 151: Atmospheres
Take a quick breath. There, that’s what we’re going to talk about today – the atmosphere. And not just the Earth’s familiar atmosphere, but the strange, exotic and deadly atmospheres we find in the Solar System and surrounding extrasolar planets.