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Universe Today - A Puzzling Difference

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 t ...

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Imagine a solar powered sail that could propel a space craft through the vacuum of space like a wind that drives a sail here on Earth. The energy of photons steaming from the Sun alone would provide the thrust. NASA and other space agencies are taking the idea seriously and are working on various prototype technologies. Edward Montgomery is the Technology Area Manager of Solar Sail Propulsion at NASA. They just tested a 20-meter (66 foot) sail at the Glenn research center's Plum Brook facil ...

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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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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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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 fir ...

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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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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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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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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 Princip ...

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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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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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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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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 Sokolo ...

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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 ...

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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 c ...

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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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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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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 ...

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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 everybeen, so if you've ever wanted to get into this hobby, maybe you'll get inspired. Bef ...

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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 distan ...

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