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11/09/2007 03:00 PM
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Universe Today - When White Dwarfs Collide
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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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11/02/2007 04:00 PM
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Universe Today - Rising Winds from Supermassive Black Holes
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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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11/30/2006 01:00 AM
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Universe Today - HiRISE View of Mars
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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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09/26/2006 02:20 PM
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Astronomy Cast - Hot Jupiters and Pulsar Planets
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You have lived on the Earth all your life, so youd 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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09/20/2006 01:00 AM
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Astronomy Cast - In Search of Other Worlds
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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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09/14/2006 01:33 PM
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Astronomy Cast - Pluto's Planetary Identity Crisis
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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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08/03/2006 09:00 PM
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Universe Today - A Puzzling Difference
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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, theres 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, youll see a galaxy in front 25% of the time. But for gamma ray bursts, theres 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 theyve found, and what could be the cause.
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07/24/2006 07:30 PM
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Universe Today - Inevitable Supernova
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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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06/03/2006 02:00 AM
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Universe Today - See the Universe With Gravity Eyes
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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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05/13/2006 08:00 PM
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Universe Today - We're Safe From Gamma Ray Bursts
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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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