Fraser Cain
Universe Today
Dr. Pamela Gay
CosmoQuest
For the longest time, the only gas giant planets we knew about were Jupiter and Saturn. But now in the age of extrasolar planets, astronomers have discovered thousands of gas giants across almost as many star systems. What new discoveries have been made about gas giants, both here in the Solar System and across the Milky Way?
Good news! Over the next few years, we’re going to see a flotilla of new missions headed to Jupiter and Saturn. Why aren’t we seeing more missions to the outer planets, like Uranus and Neptune? It turns out, those places are far away. Today let’s talk about the challenge of exploring the outer Solar System.
The outer Solar System is far enough from the Sun that water doesn’t get blasted away into deep space. In this icy realm, there are many worlds with vast quantities of water ice. Today let’s look at the icy outer moons and dwarf planets.
We’re learning more and more about the outer planets of the Solar System. Uranus and Neptune are ice giants, filled with water and other volatiles that we’d consider ice if it was here on Earth. What’s inside these worlds, and what could we expect to find across the Milky Way?
Recent Episodes
We don't like to cover news on Astronomy Cast, but sometimes there's a news story that's interesting, complicated, and rapidly unfolding - and it happens to cover an area that we haven't talked much about. So today we thought we'd talk about the discovery of...
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...
Time for another action-packed double episode of Astronomy Cast. This week we focus on the Lyman Spitzer, a theoretical physicist and astronomer who worked on star formation and plasma physics. Of course, this will lead us into next week's episode where we talk about...
Last week we talked about fusion, where atoms come together to form heavier elements. This week, everything comes apart as we talk about nuclear fission. How it occurs naturally in the Universe, and how it has been harnessed by science to produce power, and...
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...
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? Download Ep. 204: Temperature Jump to Shownotes Jump to...
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...
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...
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...
The first interplanetary series of missions was the American Mariner program. These successful spacecraft visited Mercury, Venus, and Mars, and laid the groundwork for the US missions to the outer planets. Let's take a look at the program and their incredible...
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...
Space missions are expensive to build and launch, so there's a lot of planning that goes into choosing exactly what's going to be shot into space. Space scientists and engineers recently went through the process of deciding on their science goals, so we thought we'd...
In this special live Dragon*Con 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...
Astronomers measure the brightness of stars as magnitude. But this brightness depends on the distance to the star as well as the total amount of energy it's pumping out into space. And from our vantage point here on Earth, appearances can be deceiving. Download Ep....
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...
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...
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....
The Chandra X-Ray Observatory is the third of NASA's Great Observatories, sent into space aboard the space shuttle to view the Universe in high energy X-ray radiation. This is the territory of supernovae, supermassive black holes and neutron stars; some of the most...
The first half of the 20th Century was a productive time for astronomy, with theorists working out much of the science that we take for granted today. One of these astronomy stars was Subrahmanyan Chandrasekhar, who determined the maximum mass of a white dwarf star....
Last week we studied Kepler the man, and this week we take a look at Kepler, the mission. Launched in March, 2009, this is a spacecraft designed to search for Earth-like planets orbiting other stars. Let's take a look at the history this mission, the launch and the...