The Milky Way is a vast grand spiral today, but how did it get this way? Astronomers are starting to unravel the history of our galaxy, revealing the ancient collisions with dwarf galaxies, and how they came together to build the Milky Way.
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Fraser Cain
Universe Today
Dr. Pamela Gay
CosmoQuest
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18 Seasons
700+ Episodes
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Ep. 633: Weirdly Habitable Places
We’ve always assumed that habitable planets would need to be like Earth; a terrestrial planet orbiting a sunlike star. But now astronomers have been discovering planets in the habitable zone around very much non-sunlike stars. What strange places could be habitable?
Ep. 632: Building Images: Optical vs. Radio
A recent image from the South African Meerkat telescope blew our minds. It was a high resolution image of the center of the Milky Way, showing delicate filaments and other structures. What was so mind blowing is that this was an image from a radio telescope. Today we’re going to talk about why this was such an accomplishment and what the future holds for radio astronomy.
Ep. 631: All the Uses of Pulsars (Including Murder)
Pulsars are the rapidly spinning degenerate husks of dead stars, turning hundreds of times a second. But they’re also handy clocks, spinning with such certainty and accuracy that astronomers can use them for all kinds of stuff. We might even use them to navigate the cosmos.
Recent Episodes
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?...
Ep. 165: Doppler Effect
You know how a police siren changes sound when it passes by you? That's the doppler effect. It works for sound waves and it works for light waves. Astronomers use the doppler effect to study the motion of objects across the Universe, from nearby extrasolar planets to...
Ep. 164: Inside the Atom
We've talked about the biggest of the big, now let's focus in on the smallest of the small. Let's see what's inside that basic building block of matter: the atom. You probably know the basics, but with ever more powerful particle accelerators, physicists are revealing...
Ep. 163: Auroras
When the Sun's solar winds crash into the Earth's magnetosphere, we get to enjoy an incredible light show called auroras, or the Northern and Southern Lights. Let's learn about what causes these incredible phenomena, and the best times and places that you can see them...
Ep. 162: Edwin Hubble
You might know the name "Hubble" because of the Hubble Space Telescope. But this phenomenal observatory was named after one of the most influential astronomers in modern history. Hubble discovered that galaxies are speeding away from us in all directions, leading to...
Ep. 161: Launch Facilities
Launching a rocket into space requires a big effort on the ground. Space agencies have built up huge infrastructures to store, prepare and launch rockets. Let's take a look at what's involved on the ground at a place like Cape Canaveral. What happens before, during...
Ep. 160: Eclipses
Every now and then, the Moon destroys the Sun. Okay, not destroys, covers. Well, not really covers, but from here on Earth, sitting inside the shadow of the Moon, that's what it sure looks like. These events are called eclipses, or more precisely, transits and...
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...
Ep. 158: Pulsars
Imagine an object with the mass of the Sun, crushed down to the size of Manhattan. Now set that object spinning hundreds of times a second, blasting out powerful beams of radiation like a lighthouse. That's a pulsar, one of the most exotic objects in the Universe. Ep....
Ep. 157: Constellations
Did you know there are 88 constellations in the night sky? Let's learn about the constellations and other star formations, their history, their connection to the zodiac, and how to find some of them. Ep. 157: Constellations Jump to Shownotes Jump to Transcript or...
Ep. 156: Famous Stars
This week we're going to talk about famous stars. But not those boring human ones you read about in People magazine. No, we're talking about those hot balls of plasma across the distant Universe. The close ones, the bright ones, the massive ones, the giant ones. Let's...
Ep. 155: Dwarf Stars
We think we live near an average star, but that's not the case at all. Compared to most stars in the Universe, the Sun is a giant! Let's look at the small end of the stellar spectrum, to stars with a fraction of the size and mass of our own Sun. There are many ways...