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.
Our Hosts
Fraser Cain
Universe Today
Dr. Pamela Gay
CosmoQuest
Production by
- Richard Drumm, Audio Engineer
- Ally Pelphrey, Video Engineer
18 Seasons
700+ Episodes
2018 Winner Parsec Award
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
Questions Show: Matter Balance, Jumping Light Speed and Black Hole Star Formation
Why was there a difference between the amount of matter and antimatter at the beginning of the Universe? Mathematics lets us travel faster than light speed, so why can't we? And are there stars forming around black holes? If you've got a question for the Astronomy...
Ep. 143: Astrobiology
We know there's life in the Universe. We see it all around us here on Earth. But is there life anywhere else? By studying the extremes that life can take here on Earth, scientists are learning just how hardy and adaptable life can really be. And if you consider other...
Questions Show: Black black holes, Unbalancing the Earth, and Space Pollution
Why are black holes black? Can a huge mass of humanity make the Earth wobble? And what's so bad about space pollution anyway? If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we'll try to tackle it for a future...
Ep. 142: Plate Tectonics
The surface of the Earth feels solid under your feet, but you're actually standing on a plate of the Earth's crust. And that plate is slowly shifting across the surface of the Earth. Over geologic timescales, plate tectonics has totally resurfaced our planet, bringing...
Questions Show: Avoiding the Heat Death, Orbiting Galaxies, and the Dangers of Space Radiation
Will robots be able to avoid the heat death of the Universe? Can galaxies orbit each other like binary stars? And what are the dangers of space radiation to astronauts on the Moon? If you've got a question for the Astronomy Cast team, please email it in to...
Ep. 141: Volcanoes, Hot and Cold
You're familiar with volcanoes, eruptive vents where hot magma escapes the Earth's interior - sometimes with disastrous effects. But did you know that volcanoes have shaped many of the planets and moons in the Solar System, not just our own Earth? And just in the last...
Ep. 140: Entanglement
One of the most amazing aspects of quantum mechanics is quantum entanglement. This is the strange behavior where particles can become entangled, so they're somehow connected to one another - no matter the distance between them. Interact with one particle and the other...
Questions Show: Galileoscope, Black Hole Time, and What Exactly is Energy?
How can you get a Galileoscope of your very own? What happens to time inside a black hole? And what exactly is energy anyway? If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we'll try to tackle it for a future...
Questions Show: Telescope Suggestions, Black Hole Energy, and Universal Time
What starting telescope equipment does the Astronomy Cast team suggest? How much energy does a black hole generate? And how do we measure time outside the Earth? If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and...
Ep. 139: Energy Levels and Spectra
Last week we took a peek into the tiny world of quantum mechanics, and its unintuitive, but very accurate mathematical predictions. And although we all appreciate the physics lesson, you're probably wondering what this all has to do with astronomy. Well, today we...
Questions: An Unlocked Moon, Energy Into Black Holes, and the Space Station's Orbit
What would happen if the Moon wasn't tidally locked to the Earth? What happens to all that mass and energy disappearing into a black hole? And how can we explain the space station's crazy orbit? If you've got a question for the Astronomy Cast team, please email it in...
Ep. 138: Quantum Mechanics
Quantum mechanics is the study of the very tiny; the nature of reality at the smallest scale. It's a science that defies common sense, and delivers no helpful analogies. And yet it delivers the goods, making scientific predictions with incredible accuracy. Let's look...
Questions Show: Hidden Fusion, the Speed of Neutrinos, and Hawking Radiation
Are new stars dark until their photons reach the surface? How fast do neutrinos travel? And what’s the story with Hawking Radiation? If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we'll try to tackle it for a...
Ep. 137: Large Scale Structure of the Universe
This week we’re going to think big. Bigger than big. We’re going to consider the biggest things in the Universe. If you could pull way back, and examine regions of space billions of light-years across, what would you see? How is the Universe arranged at the largest...
Questions Show: The Source of Atmospheres, the Vanishing Moon, and a Glow After Sunset
How do planets get their atmospheres? What would happen to the Earth if the Moon just disappeared? And what’s that strange glow we see after sunset? If you've got a question for the Astronomy Cast team, please email it in to info@astronomycast.com and we'll try to...
Ep. 136: Gamma Ray Astronomy
And now we reach the end of our tour through the electromagnetic spectrum. Last stop… gamma rays. These are the most energetic photons in the Universe, boosted up to incredible energies in the most violent places in the Universe. Gamma rays are tricky to catch, but...
Questions Show: Dangerous Solar Flares, Higgs Boson Insights, and Light Speed Flashlights
Can our Sun generate a solar flare that would wipe out life on Earth? Has the Large Hadron Collider answered any questions about the Higgs boson? And what would happen if you shined your flashlight out the front window of a spaceship going almost the speed of light?...
Ep. 135: X-Ray Astronomy
We continue our journey through the electromagnetic spectrum with X-rays. If you've ever broken a bone, you probably know how X-rays are most commonly used. While doctors use X-rays to study the human body, and astronomers use X-rays to study some of the hottest...
Questions Show: NorthEast Astronomy Forum (NEAF)
Pamela was lucky enough to attend the NorthEast Astronomy Forum, and while she was there she held a live questions show. And now you get to join in an hear the interesting questions, and Pamela's interesting answers. If you've got a question for the Astronomy Cast...
Ep. 134: Ultraviolet Astronomy
Our next visit in this tour through the electromagnetic spectrum is the ultraviolet. You can't see it, but anyone who's spent a day out in the hot sun without sunblock has sure experienced its effects. Ultraviolet radiation is associated with the birth of stars and...