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  • Shows Index
    • Aliens (1)
    • Amateur Astronomy (5)
      • Observing (5)
    • Astronomy (131)
      • Cosmology (22)
      • Galaxies (10)
      • Nebulae (2)
      • Observing (14)
      • Planets (39)
        • Extrasolar Planets (5)
        • Our Solar System (32)
      • Stars (18)
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        • Stellar Evolution (8)
    • Chemistry (1)
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    • Listeners (40)
      • Questions Shows (35)
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    • Planetary Science (1)
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    • The Show (3)
      • Meetups (1)



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    Past Shows
    • Questions Show: Avoiding the Heat Death, Orbiting Galaxies, and the Dangers of Space Radiation
    • Ep. 141: Volcanoes, Hot and Cold
    • Ep. 140: Entanglement
    • Questions Show: Galileoscope, Black Hole Time, and What Exactly is Energy?
    • Questions Show: Telescope Suggestions, Black Hole Energy, and Universal Time
    • Ep. 139: Energy Levels and Spectra
    • Questions: An Unlocked Moon, Energy Into Black Holes, and the Space Station's Orbit
    • Ep. 138: Quantum Mechanics
    • Questions Show: Hidden Fusion, the Speed of Neutrinos, and Hawking Radiation
    • Ep. 137: Large Scale Structure of the Universe
    • Questions Show: The Source of Atmospheres, the Vanishing Moon, and a Glow After Sunset
    • Ep. 136: Gamma Ray Astronomy
    • Questions Show: Dangerous Solar Flares, Higgs Boson Insights, and Light Speed Flashlights
    • Ep. 135: X-Ray Astronomy
    • Questions Show: NorthEast Astronomy Forum (NEAF)
    • Ep. 134: Ultraviolet Astronomy
    • Ep. 133: Optical Astronomy
    • Questions Show: Undoing Inflation, Searching for Water, and Seeing Everything a Black Hole's Ever Eaten
    • Ep. 132: Infrared Astronomy
    • Episode 131: Submillimeter Astronomy
    • Questions Show: Decelerating Black Holes, Earth-Sun Tidal Lock, and the Crushing Gravity of Dark Matter
    • Episode 130: Radio Astronomy
    • Questions Show: Multiple Big Bangs, Satellite Collisions and the Size of the Universe
    • Ep. 129: Interferometry
    • Questions Show: Shooting Lasers at the Moon and Losing Contact with Rovers
    • Ep. 128: Dust
    • Ep. 127: The US Space Shuttle
    • Ep. 126 From Skeptics Guide with Questions
    • Ep. 125: A Zoo of Extrasolar Planets
    • Questions Show: Moons and the Drake Equation, Stars in the Void, and Rings Around Stars
    • Ep. 124: Space Capsules, Part 1 – Vostok, Mercury and Gemini
    • Ep. 123: Homogeneity
    • Ep. 122: How Old is the Universe?
    • Questions Show: Stellar Roche Limits, Seeing Black Holes, and Water on Mars
    • Ep. 121: Spacesuits
    • Ep. 120: The Christmas Star
    • Questions Show: Different Fields of Astronomy, Our Sibling Stars, and Hidden Lagrange Points
    • Ep. 119: Robots in Space
    • Questions Show: Distance in Space, Changing Earth's Orbit, and Different Sized Stars
    • Ep. 118: Sky Surveys
    • Ep. 117: Time
    • Ep. 116: Molecules in Space
    • Ep. 115: The Moon, Part 3: Return to the Moon
    • Questions Show: Spiral Arms, Seismic Waves on the Sun, and our Favorite Gear
    • Ep. 114: The Moon, Part 2 – Exploration of the Moon
    • Questions Show: Ice in Space, Expansion of the Universe, and Death from the Skies
    • Ep. 113: The Moon, Part 1
    • Questions Show: Orbit of the Planets, Green Stars, and Oort Cloud Contamination
    • Ep. 112: Death From the Skies, Interview with Phil Plait
    • Questions Show: Relativity, Relativity and More Relativity
    • Ep. 111: Nebulae
    • Questions Show: Galactic Dust, the Speed of Photons, and the Big Bang Calculations
    • Ep. 110: The Search for Extraterrestrial Intelligence
    • Questions Show: Alignment with the Galactic Plane, Destruction from Venus, and the Death of the Solar System
    • Ep. 109: The Life of Other Stars
    • Questions Show – Running Out of Gravitons and Hitting the Brakes at Light Speed
    • Ep. 108: The Life of the Sun
    • Questions Show – light speed, Andromeda galaxy, dark matter and black holes
    • Ep. 107: Nucleosynthesis: Elements from Stars
    • Questions Show – Black Hole Surfaces, Magnetic Field Strengths, and the Speed of Gravitons
    • Ep. 106: The Search for the Theory of Everything
    • Student Questions Show: Leelanau School
    • Ep. 105: The Strong and Weak Nuclear Forces
    • Ep 104: Science Fiction at Dragon*Con with Plait and Grazier
    • Ep. 103: Electromagnetism
    • Ep 102: Gravity
    • Ep. 101: Advanced Propulsion Systems
    • Ep. 100: Rockets
    • Ep. 99: The Milky Way
    • Ep. 98: Quasars
    • Ep. 97: Galaxies
    • Ep. 96: Humans to Mars, Part 3 – Terraforming Mars
    • Student Questions: Collinsville High School
    • Ep. 95: Humans to Mars, Part 2 – Colonists
    • Ep 94: Humans to Mars, Part 1 – Scientists
    • Ep. 93: Missions to Mars, Part 2
    • Ep. 92: Missions to Mars, Part 1
    • Ep. 91: The Search for Water on Mars
    • Ep. 90: The Scientific Method
    • Ep. 89: Adaptive Optics
    • Ep. 88: The Hubble Space Telescope
    • Ep. 87: The End of the Universe Part 2: The End of Everything
    • Ep. 86: The End of the Universe Part 1: The End of the Solar System
    • Ep. 85: Detectors
    • Ep. 84: Getting Around the Solar System
    • Ep. 83: Wave Particle Duality
    • Ep. 82: Space Junk
    • Ep. 81: Questions on the Shape, Size and Centre of the Universe
    • Ep. 80: Craters
    • Ep. 79: How Big is the Universe?
    • Ep. 78: What is the Shape of the Universe?
    • Ep. 77: Where is the Centre of the Universe?
    • Ep. 76: Lagrange Points
    • Student Questions: Curtis High School
    • Ep. 75: Stellar Populations
    • Ep. 74: Antimatter
    • Ep. 73: Questions Show #8
    • Ep. 72: Cosmic Rays
    • Ep. 71: Gravitational Waves
    • Ep. 70: How To Win a Nobel Prize
    • Student Questions: Farmersburg
    • Ep. 69: The Large Hadron Collider and the Search for the Higgs-Boson
    • Ep. 68: Globular Clusters
    • Ep. 67: Building a Career in Astronomy
    • Ep. 66: How Amateurs Can Contribute to Astronomy
    • Ep. 65: The End of Our Tour Through the Solar System
    • Ep. 64: Pluto and the Icy Outer Solar System
    • Ep. 63: Neptune
    • Ep. 62: Uranus
    • Ep. 61: Saturn's Moons
    • Ep. 60: Questions Show #7
    • Ep. 59: Saturn
    • Ep. 58: Inflation
    • Ep. 57: Jupiter's Moons
    • Ep. 56: Jupiter
    • Ep. 55: The Asteroid Belt
    • Ep. 54: Questions Show #6
    • Ep. 53: Astronomy in Science Fiction
    • Special Episode: Panspermia
    • Ep. 52: Mars
    • Ep. 51: Earth
    • Ep. 50: Venus
    • Ep. 49: Mercury
    • Ep. 48: Tidal Forces Across the Universe
    • Ep. 47: Tidal Forces
    • Ep. 46: Stellar Nurseries
    • Ep. 45: The Important Numbers in the Universe
    • Listener Survey
    • Ep. 44: Einstein's Theory of General Relativity
    • Ep. 43: Questions Show #5
    • Ep. 42: Magnetism Everywhere
    • Ep. 41: The Rise of the Supertelescopes
    • Ep. 40: American Astronomical Society Meeting, May 2007
    • Ep. 39: Astrology and UFOs
    • Ep. 38: Neutron Stars and their Exotic Cousins
    • Ep. 37: Gravitational Lensing
    • Ep. 36: Gamma-Ray Bursts
    • Ep. 35: Questions Show #4
    • Ep. 34: Discovering Another Earth
    • Ep. 33: Choosing and Using a Telescope
    • Ep. 32: The Search for Neutrinos
    • Ep. 31: String Theory, Time Travel, White Holes, Warp Speed, Multiple Dimensions, and Before the Big Bang
    • Ep. 30: The Sun, Spots and All
    • Ep. 29: Asteroids Make Bad Neighbors
    • Ep. 28: What is the universe expanding into?
    • Ep. 27: Questions Show #3
    • Ep. 26: The Largest Structures in the Universe
    • Ep. 25: The Story of Galaxy Evolution
    • Ep. 24: The Fermi Paradox: Where Are All the Aliens?
    • Ep. 23: Counting Aliens With the Drake Equation


Questions Show – light speed, Andromeda galaxy, dark matter and black holes

  • September 26th, 2008
  • Show Notes
  • Comments(12)
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Another week, another roundup of your questions. This week listeners asked: will reaching light speed destroy the Universe? When is Andromeda going to look really, really cool with the unaided eye? Why didn't dark matter all turn into black holes? And there's even more. 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 show.

Show – light speed, Andromeda galaxy, dark matter and black holes (17.07MB)
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Ep. 99: The Milky Way

  • July 30th, 2008
  • Show Notes
  • Comments(6)
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Artist illustration of the Milky Way. Image credit: NASA
The Milky Way is our home. An island of stars in a universe of other galaxies. But you might be surprised to learn that astronomers have only known the Milky Way's true nature for just a century. Let's learn the history of discoveries about the Milky Way, and what today's science tells us. And let's peer into the future to learn the ultimate fate of our galaxy.

Ep. 99: The Milky Way
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Ep. 98: Quasars

  • July 22nd, 2008
  • Show Notes
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Artist illustration of a quasar. Image credit: NASA
Last week we talked about galaxies in general, and hinted at the most violent and energetic ones out there: active galaxies. Quasars have been a mystery for half a century; what kind of object could throw out more radiation than an entire galaxy? A black hole, it turns out, with the mass of hundreds of millions of suns performs this feat. Let's trace back the history of quasars, how they were first discovered and puzzled astronomers for so long. And let's look at what we know today.

Ep. 98: Quasars
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Ep. 97: Galaxies

  • July 15th, 2008
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Whirlpool Galaxy. Image credit: Hubble
This week we're going to look at some of the biggest objects in the Universe: galaxies. It was the discovery of galaxies in the early 20th century that helped astronomers realize just how big the Universe is, and how far away everything is. Let's learn how galaxies formed and how they evolve and change over time, merging with the neighbors. And what the future holds.

Ep. 97: Galaxies
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Ep. 72: Cosmic Rays

  • January 21st, 2008
  • Show Notes
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This active galaxy (3C442A) is emitting high-energy particles through its poles, as you can see with the xray/radio composite.
We're going to return back to a long series of episodes we like to call: Radiation that Will Turn You Into a Superhero. This time we're going to look at cosmic rays, which everyone knows made the Fantastic Four. These high-energy particles are streaming from the Sun and even intergalactic space, and do a wonderful job of destroying our DNA, giving us radiation sickness, and maybe (hopefully!) turning us into superheroes.

Episode 72: Cosmic Rays (13.3MB)
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Ep. 68: Globular Clusters

  • December 24th, 2007
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M80 is a globular cluster 28,000 light years away containing thousands of stars.
This week we're going to study some of the most ancient objects in the entire Universe; globular clusters. These relics of the early Universe contain hundreds of thousands of stars, held together by their mutual gravity. Since they formed together, they give astronomers a unique way to test various theories of stellar evolution.

Episode 68: Globular Clusters (14.3MB)
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Ep. 37: Gravitational Lensing

  • May 21st, 2007
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Galaxy cluster Abell 2218 is acting as a powerful lens, magnifying all galaxies lying behind the cluster core.
Astronomers are always trying to get their hands on bigger and more powerful telescopes. But the most powerful telescopes in the Universe are completely natural, and the size of a galaxy cluster. When you use the gravity of a galaxy as a lens, you can peer right back to the edges of the observable Universe.

Episode 37: Gravitational Lensing (12.7MB)
 
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Ep. 26: The Largest Structures in the Universe

  • March 5th, 2007
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NGC 5257 & 5258
This week we continue the story of galaxy formation, learning how groups of galaxies come together to form the biggest structures around – galaxy superclusters. And when you look at the Universe at this scale, environment is everything.

 

Episode 26: The Largest Structures in the Universe (15 MB)
 
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Ep. 25: The Story of Galaxy Evolution

  • February 26th, 2007
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Active Galaxy M87
Our Milky Way is a complex and majestic barred spiral galaxy. But 13.7 billion years ago it began, like all galaxies, from the elementary particles formed in the Big Bang. How did our galaxy grow from nothing to the hundreds of billions of stars we see today?

 

Episode 25: The Story of Galaxy Evolution (13.8 MB)
 
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Ep. 18: Black Holes Big and Small

  • January 8th, 2007
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Black Hole (Artist Illustration)
We're finally ready to deal with the topic you've all been waiting for: Schwarzschild swirlers, Chandrasekhar crushers, ol' matter manglers, sucking singularities… you might know them as black holes. Join as as we examine how black holes form, what they consume, and just how massive they can get.

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