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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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.
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: http://www.tvdavisastropics.com.
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.
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.
With new instruments, astronomers are filling in all the pieces that help to explain how planets form out of extended disks of gas and dust around newborn stars. This process seems to happen quickly, often just a few million years is all it takes to go from dust to planets. But astronomers have found one proto-planetary disk that refuses to grow up. It's 25 million years old, and still hasn't made the transition to form planets. Lee Hartmann is with the Harvard-Smithsonian Center for Astrophysics, and the lead author on the paper announcing the find.
Ah, summer. Long relaxing days spent at the lake, just swimming, fishing, and enjoying the scenery. Think you can only enjoy lakes here on Earth? Well, think again. NASA's Cassini spacecraft might have turned up a lake on Titan, Saturn's largest moon. It might not be the kind of lake you're used to though. The average temperature on Titan is only a hundred degrees above Absolute Zero, so it's probably a lake of liquid hydrocarbons. Carolyn Porco is the leader on the imaging team on the Cassini mission to Saturn and the director for the Center of Imaging Operations at the Space Science Institute in Boulder, Colorado. That's where the images from Cassini are processed and released to the public.
How many times have I been to space? Well, I lost count at, oh, none. So I, and nearly every other human being on Earth can't compare with Story Musgrave, a legendary NASA astronaut who flew on the space shuttle six times, including leading the team that fixed the Hubble Space Telescope's vision in 1993. He's the subject of a recent biography called Story: the Way of Water, and has a new CD called Cosmic Fireflies, which sets his space inspired poetry to music. Story speaks to me from his home in Florida.
If you're an astronomer and you want to escape the Earth's hazy atmosphere, you need a space telescope... right? Not necessarily, sometimes all you need is a balloon, and some clear arctic skies. An international team of researchers traveled to Sweden and deployed a 33-storey tall balloon carrying the BLAST telescope, designed to study the birth of stars and planets. Gaelen Marsden is a member of the team, and researcher at the University of British Columbia in Vancouver, Canada.
When you look into the night sky with your eyes, or through a telescope, you're seeing the Universe in the spectrum of visible light. Unfortunately, this is a fraction of the entire electromagnetic spectrum, ranging from radio waves to gamma radiation. And that's too bad because different wavelengths are better than others for revealing the mysteries of space. Technology can let us "see" what our eyes can't, and instruments here on Earth and in space can detect these different kinds of radiation. The submillimeter wavelength is part of the radio spectrum, and gives us a very good view of objects which are very cold - that's most of the Universe. Paul Ho is with the Harvard-Smithsonian Center for Astrophysics, and an astronomer working in world of the submillimeter. He speaks to me from Cambridge, Massachusetts.
July 4th is Independence Day In the United States, and Americans typically enjoy their holiday with a few fireworks. But up in space, 133 million kilometres away, there's going to be an even more spectacular show... Deep Impact. On July 4th, a washing machine-sized spacecraft is going to smash into Comet Tempel 1, carve out a crater, and eject tonnes of ice and rock into space. The flyby spacecraft will watch the collision from a safe distance, and send us the most spectacular pictures ever taken of a comet - and its fresh bruise. Dr. Lucy McFadden is on the science team for Deep Impact, and speaks to me from the University of Maryland.
Asteroids have been roughing up the Earth since it formed 4.6 billion years ago. Hundreds of thousands of potentially devastating asteroids are still out there, and whizzing past our planet all the time. Eventually, inevitably, one is going to score a direct hit and cause catastrophic damage. But what if we could get a better idea of where all these asteroids are or even learn to shift their orbits? Dr Edward Lu is a NASA astronaut, and a member of the B612 Foundation - an organization raising awareness about the threat of these asteroids and some potential solutions.
Professional astronomers have got some powerful equipment at their disposal: Hubble, Keck, and Spitzer, just to name a few. But many discoveries rely on the work of amateurs, using equipment you could buy at your local telescope shop. And recently, amateurs helped discover a planet orbiting another star 15 thousand light-years away. Grant Christie is an amateur astronomer from Auckland New Zealand, and is part of the team that made the discovery.
Wormholes are a mainstay in science fiction, providing our heroes with a quick and easy way to instantly travel around the Universe. Enter a wormhole near the Earth and you come out on the other side of the galaxy. Even though science fiction made them popular, wormholes had their origins in science - distorting spacetime like this was theoretically possible. But according to Dr. Stephen Hsu from the University of Oregon building a wormhole is probably impossible.
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 facility in Sandusky, Ohio.
There's a number in the Universe which we humans call alpha - or the fine structure constant. It shows up in almost every mathematical formula dealing with magnetism and electricity. The very speed of light depends on it. If the value for alpha was even a little bit different, the Universe as we know it wouldn't exist - you, me and everyone on Earth wouldn't be here. Some physicists have recently reported that the value for alpha has been slowly changing since the Big Bang. Others, including Jeffrey Newman from the Lawrence Berkeley National Laboratory have good evidence that alpha has remained unchanged for at least 7 billion years.
Let's say you're browsing around the comic book store and happened to notice a perfect copy of Action Comics #1 on the rack mixed in with the current stuff. It's in mint condition, untouched since it was first printed almost 70 years ago. Now imagine the same situation... except with stars. Anna Frebel is a PhD student at the Research School of Astronomy and Astrophysics at the Australian National University. She's working with a team of astronomers who have found the oldest star ever seen - possibly untouched since shortly after the Big Bang.
In case you missed the news, NASA is headed back to the Moon in the next decade. A permanent lunar base could be down the road, so scientists are starting to consider where we should build. Ben Bussey, with Johns Hopkins University in Maryland likes the Moon's North Pole. It's got everything you might need for a long-term stay: permanent sunlight, relatively stable temperatures, and lots of lunar soil. And as an added bonus, there might be plenty of frozen water hiding in lunar craters.
Wolf-Rayet stars are big, violent and living on borrowed time. Put two of these stars destined to explode as supernovae in a binary system, and you've got an extreme environment, to say the least. Sean Dougherty, an astronomer at the Herzberg Institute for Astrophysics in Canada has used the Very Long Baseline Array radio telescope to track a binary Wolf-Rayet system. The two stars are blasting each other with ferocious stellar winds. This is one fight we're going to stay well away from.
Black holes... you know. Cosmic singularities that can contain the mass of billions of stars like our Sun. Where the pull of gravity is so strong, nothing, not even light can escape their fearsome grasp. They're the source of much discussion, indirect observation and science fiction speculation. But according to George Chapline from Lawrence Livermore National Laboratory in California, they don't exist. Instead we have dark energy stars, which are connected to that mysterious force accelerating the expansion of the Universe.
Remember Sedna? It's that icy object uncovered last year in the outer reaches of the Solar System. When it was first discovered, astronomers noticed it rotated once every 20 days. The only explanation that could explain this slow rotation was a moon, but a moon never showed up in any of their observations. Scott Gaudi is a researcher with the Harvard Smithsonian Centre for Astrophysics. He and his colleagues have been watching the rotation of Sedna with a skeptical eye, and think it's only rotating once every 10 hours or so. As for the moon? Easy come, easy go.
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. The podcasts are short (10-15 minutes long) and very focused.
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