Universe Today
Universe Today is a daily summary of the latest space and astronomy - I've been publishing it daily since 1999. In this audio edition, I interview astronauts, astronomers, and scientists about their latest research.
Copyright: 2005 Universe Today
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Universe Today - When White Dwarfs Collide[Duration 00:12:09, 5.6 MB]Fri, 9 Nov 2007 12:00:00 -0800
There's a certain kind of supernova that's totally dependable. Let a white dwarf accumulate 1.4 times the mass of the Sun, and it'll detonate in an explosion visible clear across the Universe. When astronomers saw supernova 2006gz, that's what they thought they were dealing with, but hold on, the explosion was much more powerful than you would expect from just a single white dwarf. Maybe two came together in a colossal explosion.
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Universe Today - Rising Winds from Supermassive Black Holes[Duration 00:13:57, 6.4 MB]Fri, 2 Nov 2007 12:00:00 -0800
Astronomers now believe there's a supermassive black hole lurking at the heart of every galaxy. When these monsters are actively feeding, an accretion disk of material builds up around them, like swirling water waiting to go down the drain. For the first time, astronomers have detected winds rising up from this disk of doomed material. And it turns out, these winds have a profound impact on the surrounding galaxy.
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If you want to get a good view of something, you'll want a big telescope, or you want to get close. NASA has decided to both, equipping its new Mars Reconnaissance Orbiter with the largest spacecraft telescope ever built, and then flying it closer to Mars than any previous spacecraft. This telescope is called the High Resolution Imaging Science Experiment, and returning the most detailed images ever seen of the Martian surface. Dr. Alfred McEwen from the University of Arizona is the Principal Investigator on the HiRise instrument, and he joins me from Tuscon Arizona.
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Astronomy Cast - Hot Jupiters and Pulsar Planets[Duration 00:28:13, 12.9 MB]Tue, 26 Sep 2006 10:20:00 -0800
You have lived on the Earth all your life, so you'd think you know plenty about planets. As usual though, the Universe is stranger than we assume, and the planets orbiting other stars defy our expectations. Gigantic super-Jupiters whirling around their parent stars every couple of days; fluffy planets with the density of cork; and Earth-sized fragments of exploded stars circling pulsars. Join us as we round up the latest batch of bizarro worlds.
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Astronomy Cast - In Search of Other Worlds[Duration 00:30:06, 12.0 MB]Tue, 19 Sep 2006 21:00:00 -0800
Look down at your feet. There you're looking at a planet. Now look into the night sky and you should be able to spot a few more. After that, spotting additional planets becomes really hard, especially when you're trying to find them orbiting other stars. This week we discuss the techniques astronomers use to locate distant worlds.
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Astronomy Cast - Pluto's Planetary Identity Crisis[Duration 00:25:00, 12.0 MB]Thu, 14 Sep 2006 09:33:00 -0800
Pluto. It's a planet, then it's not. This week we review Pluto's history, from discovery to demotion by the International Astronomical Union. Learn the 3 characteristics that make up a planet, and why Pluto now fails to make the grade.
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Imagine looking at red houses, and sometimes you see a crow fly past. But every time you look at a blue house, there's always a crow flying right in front of the house. The crow and the house could be miles apart, so this must be impossible, right? Well, according to a new survey if you look at a quasar, you'll see a galaxy in front 25% of the time. But for gamma ray bursts, there's almost always an intervening galaxy. Even though they could be separated by billions of light years. Figure that out. Dr. Jason X. Prochaska, from the University of California, Santa Cruz speaks to me about the strange results they've found, and what could be the cause.
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Consider the dramatic binary system of RS Ophiuchi. A tiny white dwarf star, about the size of our Earth, is locked in orbit with a red giant star. A stream of material is flowing from the red giant to the white dwarf. Every 20 years or so, the accumulated material erupts as a nova explosion, brightening the star temporarily. But this is just a precursor to the inevitable cataclysm - when the white dwarf collapses under this stolen mass, and then explodes as a supernova. Dr. Jennifer Sokoloski has been studying RS Ophiuchi since it flared up earlier this year; she discusses what they've learned so far, and what's to come.
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Universe Today - See the Universe With Gravity Eyes[Duration 00:16:25, 7.5 MB]Fri, 2 Jun 2006 22:00:00 -0800
In the past, astronomers could only see the sky in visible light, using their eyes as receptors. New technologies extended their vision into different spectra: infrared, ultraviolet, radio waves, x-rays and gamma rays. But what if you had gravity eyes? Einstein predicted that the most extreme objects and events in the Universe should generate gravity waves, and distort space around them. A new experiment called Laser Interferometer Gravitational Wave Observatory (or LIGO) could make the first detection of these gravity waves.
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Universe Today - We're Safe From Gamma Ray Bursts[Duration 00:12:36, 5.8 MB]Sat, 13 May 2006 16:00:00 -0800
We live in a dangerous Universe. Our tiny home planet is at risk from many extraterrestrial threats: asteroid strikes, solar flares, rogue black holes, supernovae. Now add gamma ray bursts to the list - those most powerful explosions in the Universe. Even 10 seconds of radiation from one of these events would be a deadly setback to life on Earth. Before you start looking for another planet to live on, Dr. Andrew Levan from the University of Hertforshire is here to explain the probilities of a nearby explosion. It looks like the odds are in our favour.
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Universe Today - There Goes New Horizons[Duration 00:09:04, 4.2 MB]Thu, 09 Feb 2006 22:30:00 -0800
Take a look through any book on our Solar System, and you'll see beautiful photographs of every planet - except one. Eight of our nine planets have been visited up close by a spacecraft, and we've got the breathtaking photos to prove it. Pluto's the last holdout, revealing just a few fuzzy pixels in even the most powerful ground and space-based telescopes. But with the launch of New Horizons in January, bound to arrive at Pluto in 9 years, we're one step closer to completing our planetary collection - and answering some big scientific questions about the nature of objects in the Kuiper Belt. Alan Stern is the Executive Director of the Space Science and Engineering Division, at the Southwest Research Institute. He's New Horizon's Principal Investigator.
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Young hot blue star - the supermassive black hole has spoken, it's time for you leave the galaxy. When binary stars stray too close to the centre of the Milky Way, they're violently split apart. One star is put into an elliptical orbit around the supermassive black hole, and the other is kicked right out of the galaxy. Dr. Warren Brown from the Harvard-Smithsonian Center for Astrophysics was one of the astronomers who recently turned up two exiled stars.
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Universe Today - Gravity Tractor Beam for Asteroids[Duration 00:10:02, 4.6 MB]Thu, 29 Dec 2005 11:30:00 -0800
Forget about nuclear weapons, if you need to move a dangerous asteroid, you should use a tractor beam. Think that's just Star Trek science? Think again. A team of NASA astronauts have recently published a paper in the Journal Nature. They're proposing an interesting strategy that would use the gravity of an ion-powered spacecraft parked beside an asteroid to slowly shift it out of a hazardous orbit. Dr. Stanley G. Love is member of the team and speaks to me from his office in Houston.
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Universe Today - Plasma Thruster Prototype[Duration 00:11:35, 5.3 MB]Thu, 22 Dec 2005 13:00:00 -0800
If you're going to fly in space, you need some kind of propulsion system. Chemical rockets can accelerate quickly, but they need a lot of heavy fuel. Ion engines are extremely fuel efficient but don't generate a lot of power, so they accelerate over months and even years. A new thrusting technology called the Helicon Double Layer Thruster could be even more efficient with its fuel. Dr. Christine Charles from the Australian National University in Canberra is the inventor.
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What's the Universe made of? Don't worry if you don't have a clue, astronomers don't either. The Universe is dominated by a mysterious dark matter that seems to form the true mass of a galaxy, not the regular matter - like stars and planets - that we can actually see. Dr. James Jee from Johns Hopkins University used the Hubble Space Telescope to create a detailed map of dark matter concentrations around two galaxies. And astronomers just got some new clues.
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Universe Today - Best Space and Astronomy Books of 2005[Duration 00:17:44, 8.1 MB]Wed, 16 Nov 2005 22:00:00 -0800
The year is coming to a close. And in case you haven't been counting, we've reviewed more than 50 space and astronomy books on Universe Today since January. That's a lot of books, and book fiend Mark Mortimer did most of the reading and reviewing. He joins me today for a special podcast where we chat about his favorites for the year.
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Universe Today - Larry Esposito and Venus Express[Duration 00:11:29, 5.3 MB]Thu, 10 Nov 2005 22:00:00 -0800
Venus is our nearest planetary neighbour. Compared to the Earth, it's nearly identical in size and distance from the Sun. But that's where the similarities end. While we enjoy our comfortable temperature, pressure and atmosphere, Venus' environment is downright hostile to life. The European Space Agency's Venus Express blasted off for our "evil twin" planet today, and will hope to help answer the question: what went wrong? My guest today is Larry Esposito from the Laboratory for Atmospheric and Space Physics at the University of Colorado. He's a member of the Venus Express science team.
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Universe Today - The Fate of the Universe[Duration 00:13:00, 6.0 MB]Mon, 12 Sep 2005 09:00:00 -0800
How will the Universe end? Right now cosmologists have two equally distressing scenarios mapped out for the long term fate of the Universe. On the one hand, gravity might slow down the expansion of our Universe so that it coasts to a stop and possibly even collapses back down into a Big Crunch. On the other hand, the expansion of the Universe could continue indefinitely thanks to the acceleration of dark energy. We would face a cold, lonely future as other galaxies fade away into the distance. My guest today is Eric Linder from the Lawrence Berkeley National Laboratory and he's proposing experiments that could help us learn which of these two fates await us.
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Universe Today - Interview with Simon Singh[Duration 00:16:56, 7.8 MB]Wed, 31 Aug 2005 10:21:00 -0800
My guest today is Simon Singh, author of many science-related books including Fermat's Enigma, and The Code Book. His latest book, Big Bang, investigates the origins of the search for our place in an ever expanding Universe. Simon speaks to me from his home in London, England. I just want to apologize in advance for the murky audio quality - that's what you get when you call London from Canada through Skype. I've got an audio transcript that you can refer to if you're have trouble making out what Simon said.
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Universe Today - Astrophotography with Tom Davis[Duration 00:12:45, 5.8 MB]Sat, 22 Aug 2005 09:00:00 -0800
My guest today is an amateur astrophotographer named Tom Davis. Those of you who subscribe to the Universe Today newsletter should be familiar with his photographs, as I've featured several of them in the last few months. Tom is an amazingly skilled astrophotographer, and he's got some decent equipment. And I'm happy to inform you that the price for this kind of technology is more affordable than it's every been, so if you've ever wanted to get into this hobby, maybe you'll get inspired. Before you start listening, please take a moment to look at his website at: www.tvdavisastropics.com....