Astronomy Cast more than 600 episodes ago. Are there any updates? Does Pluto have a chance of regaining planethood again?
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Fraser Cain
Universe Today
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17 Seasons
700+ Episodes
Ep. 612: Update: SETI, METI (and WETI)
Last week we talked about the various ways that astronomers could detect the presence of intelligent civilizations by observing technosignatures. This week we’ll give you an update on the state of searching for extraterrestrials. This field has gone from a collection of pariahs to a completely legitimate field of research. What’s changed?
Ep. 611: What is Required to Confirm Alien Life: Intelligence Edition
Last week we talked about what it’s going to take to confirm basic biological life across the Solar System and the Milky Way. This week, we’ll discuss what it’s going to take to detect intelligent life out there in space.
Ep. 610: What is Required to Confirm Alien Life: Non-sentient Edition
Are we alone in the Universe? It’s one of the biggest scientific questions we can possibly ask. And yet, with rovers on Mars, missions planned to visit Europa and Ganymede. Powerful telescopes able to detect the atmospheres of exoplanets, we’re closer than ever to finding out the answer.
Recent Episodes
Ep. 185: History of Astronomy, Part 3: The Renaissance
Now we reach time with names that many of you will be familiar: Galileo, Kepler, Copernicus. This is an age when the biggest names in astronomy used the best tools of their time to completely rearrange their understanding of the Universe, putting the Earth where it...
Ep. 184: History of Astronomy, Part 2:The Greeks
With the earliest astronomers out of the way, we now move to one of the most productive eras in astronomy; the ancient Greeks. Even though they didn't have telescopes, the Greeks worked out the size and shape of the Earth, the distance to the Moon and Sun, and even...
Ep. 183: History of Astronomy, Part 1: The Ancient Astronomers
We know you love a good series. This time we're going to walk you through the history of astronomy, starting with the ancient astronomers and leading right up to the most recent discoveries. Today we're going to start at the beginning, with the astronomers who first...
Ep. 182: Astrometry
Astronomers have been cataloging star positions for thousands of years, from the first calculations made by Hipparchus, to the more recent star catalogs made by the spacecraft named after him. This is astrometry; another way to find our place in the Universe. Download...
Ep. 181: Rotation
Everything in the Universe is spinning. In fact, without this rotation, life on Earth wouldn't exist. We need the conservation of angular momentum to flatten out galaxies and solar systems, to make planets possible. Let's find out about the physics involved with...
Ep. 180: Albedo
Why are some objects in the Solar System bright while others are dim? Much of an object's brightness is caused by its albedo, or how well it reflects radiation from the Sun. If you want to know how big a distant moon, comet, or asteroid is, you've got to know its...
Ep. 179: Mysteries of the Universe, Part 2
Today we tackle more thrilling mysteries of the Universe. And by tackle, we mean, acknowledge their puzzling existence. Some mysteries will be solved shortly, others will likely trouble astronomers for centuries to come. Join us for part 2. Download Ep. 179: Mysteries...
Ep. 178: Mysteries of the Universe, Part 1
All finished with the Milky Way, it's time to move on to the biggest mysteries of all. The mysteries of the Universe. Let's wonder about dark matter and dark energy, and the very nature of reality itself. Download Ep. 178: Mysteries of the Universe, Part 1 Jump to...
Ep. 177: Mysteries of the Milky Way, Part 2
We survived our first group of mysteries, so now we move onto our second set of stuff of amazing Milky Way mysteries. How many spiral arms does our galaxy have, and why does everything keep dying every 60 million years or so? Download Ep. 177: Mysteries of the Milky...
Ep. 176: Mysteries of the Milky Way, Part 1
We've wrapped up our Solar System mysteries and now we move onto the Milky Way mysteries, and the some of the general mysteries of galaxies. From blue stragglers to Eta Carinae... what's going on? Download Ep. 176: Mysteries of the Milky Way, Part 1 Jump to Shownotes...
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. Download Ep. 174:...
Ep. 173: Herschel Space Observatory
Last week we talked about Herschel the people - William Herschel, his sister Caroline, and his son John. This week we look at the Herschel Space Observatory, a mission launched in 2009 to reveal the coldest and dustiest regions in the Universe. DownloadEp. 173:...
Ep. 172: William Herschel
Ancient astronomers knew of 5 planets, Mercury, Venus, Mars, Jupiter and Saturn - 6 if you count Earth. But then in 1781, William Herschel discovered an entirely new planet, boosting the number of planets to 7. Let's learn about Herschel, his equipment, his...
Ep. 171: Solar System Movements and Positions
Even in ancient times, astronomers realized there was something different about the planets - they move! The movement of the planets and their moons are governed by gravity. And as we all know, gravity can do some funny things. Download Ep. 171: Solar System Movements...
Ep. 170: Coordinate Systems
This is going to be one of those weeks where we tackle something you're mentally avoiding. You know all those astronomical terms, like alt-azimuth, right ascension and declination, arc seconds and arc minutes? Of course not, your mind has blocked them out. Today we're...
Ep. 169: The Fermi Mission
Last week we talked about Fermi the man, now we're going to talk about Fermi the space telescope. That's right, Enrico Fermi made such an impact in the astronomy and physics community that he got a space telescope named after him. Let's take a look at what this...
Ep. 168: Enrico Fermi
Today's episode of Astronomy Cast is about another famous physicist: Enrico Fermi. We've already taken a look at one of Fermi's most famous ideas, the Fermi Paradox - or, where are all the aliens? But let's meet the man behind the ideas, the namesake for the new Fermi...
Ep. 167: Future Civilizations
Let's assume that humans survive the next few hundred years without destroying ourselves, or the planet, and we actually become a space faring civilization. What kinds of challenges will we face, and what projects will we build to expand ourselves out into the Solar...
Ep. 166: Multiverses
What if our universe was just one in an infinite number of parallel universes; a possible outcome from the specific predictions of quantum mechanics. The idea of multiple universes is common in science fiction, but is there any actual science to back this theory up?...