Silicon Valley Astronomy Lectures
The Dark Side of the Universe: Dark Matter and Dark Energy
Dr. Patricia Burchat (Stanford University)
Listen (mp3 file, 19.4 MB)
In the last decade or so, astronomers have been forced to accept two mysterious observations. About a quarter of the universe is made of “dark matter,” which attracts things with its gravity, but is otherwise invisible. And roughly two-thirds of the universe is composed of “dark energy,” which causes space itself to expand at an ever-increasing rate. That means only a small fraction of the universe is made of ordinary matter — the stuff we understand! In this non-technical presentation, Dr. Burchat explores the evidence for the dark side of the cosmos, and the experiments that are being developed to investigate it further.
Planetary Protection and Hitchhikers in the Solar System: The Danger of Mingling Microbes
Dr. Margaret Race (SETI Institute)
Listen (mp3 file, 20.2 MB)
Scientists searching for life elsewhere have to worry about avoiding harmful cross contamination during the exploration of planets and their moons. We don’t want to take Earth microbes to Mars or bring back alien microbes to Earth. In this timely talk, Dr. Race gives a behind-the-scenes view of “environmental management” planning for solar system missions, and explains the role of the Outer Space Treaty and other related national and international policies in planning our hunt for life-forms out there.
The Dawn of Creation: The First Two Billion Years
Dr. Stephen Beckwith (University of California)
Listen (mp3 file, 26.4 MB)
All the great islands of stars got their start in the first billion years after the beginning of time, the Big Bang. Every deep picture of the sky reveals thousands of these galaxies, each made up of billions of stars like the Sun. Modern instruments like the Hubble Space Telescope have made it possible to look back to a time when the universe looked very different that it does today. Dr. Beckwith discusses some of the deepest images of the universe ever taken and shares recent discoveries about the early days of the cosmos.
Prospecting for Water on the Moon: The Upcoming LCROSS Mission
Dr. Anthony Colaprete (NASA Ames Research Center)
Listen (mp3 file, 16.8 MB)
In 2009, NASA will purposely crash two spacecraft into one of the Moon’s polar regions. The impacts should raise huge plumes of material, visible even to smaller telescopes on Earth. Dr. Colaprete, the Principal Investigator for this intriguing mission, fills us in on why scientists believe there is water in deep craters at the Moon’s poles and how the LCROSS mission plans to look for it in the plumes.
Saturn’s Restless Rings: Latest Results from the Cassini Mission
Dr. Mark Showalter (SETI Institute)
Listen (mp3 file, 20.7 MB)
NASA’s Cassini spacecraft has entered its fifth year exploring the planet Saturn, its rings, and its moons. Dr. Showalter, a key member of the Cassini science team, shares some of the marvelous results from Saturn and recent discoveries from the mission. His special focus is Saturn’s complex and beautiful ring system (which shows a variety of surprising phenomena, including “jets”, “propellers”, “wisps”, “spokes”, and “braids”) and the remarkable interactions between Saturn’s rings and moons.
The Black Hole Wars: My Battle with Stephen Hawking
Dr. Leonard Susskind (Stanford University)
Listen (mp3 file, 20.2 MB)
Black holes, the collapsed remnants of the largest stars, provide a remarkable laboratory where the frontier concepts of our understanding of nature are tested at their extreme limits. For more than two decades, Professor Susskind and a Dutch colleague have had a running battle with Stephen Hawking about the implications of black hole theory for our understanding of reality — a battle that he has described in his well-reviewed book The Black Hole Wars. In this talk Dr. Susskind tells the story of these wars and explains the ideas that underlie the conflict. What’s at stake is nothing less than our understanding of space, time, matter and information!
The Allen Telescope Array: The Newest Pitchfork for Exploring the Cosmic Haystack
Dr. Jill Tarter (SETI Institute)
Listen (mp3 file, 24.5 MB)
Dr. Tarter is the leader of the main project looking for radio signals from alien civilizations (she was also the model for the character Jodie Foster played in the movie “Contact.”) She updates us on the latest tools and plans in this quest, as digital technologies make possible huge improvements in our search systems. The Allen Telescope Array, being constructed in Northern California, will be the most powerful tool for finding SETI signals ever built. It is an innovative radio telescope assembled from a large number of small dishes, using consumer off-the-shelf technologies whenever possible to minimize costs. In the next decade, this new instrument will enable exploration that is 1000 to 10,000 times more sensitive than in the previous decades. This may just be enough!
New Worlds and Yellowstone: How Common are Habitable Planets?
Dr. Geoff Marcy (University of California, Berkeley)
Listen (mp3 file, 21.1 MB)
Astronomers have now discovered more than 250 planets orbiting other stars. Hear the scientist who has discovered more planets than anyone else in the history of the world discuss what kinds of planets we have found so far, and what a new generation of telescopes might find in the future. Could discoveries of planets that resemble the Earth spark a new era when we could someday begin communication with alien life? Dr. Marcy won the Shaw Prize (one of the highest honors in science) in 2005 and was Discover Magazine’s Space Scientist of the Year. He and his co-workers pioneered the technique for finding planets around other stars without seeing light from the planet (by looking for wiggles in the motion of the star each planet orbits.)
New Horizons at Jupiter (and Some Saturn News)
Dr. Jeff Moore (NASA Ames Research Center)
Listen (mp3 file, 17.4 MB)
In February, NASA’s New Horizons spacecraft swung by the giant planet Jupiter on its way to Pluto. Its instruments recorded winderful images and other data about Jupiter’s wild weather, its ring, and its giant moons. Dr. Moore, who was Leader of the Imaging Node for the encounter, shows the new photos of the Jupiter system and discusses some of the discoveries made by New Horizons. He also talks about one of the most exciting discoveries of the Cassini mission around Saturn — the new understanding and exploration of water geysers on the moon Enceladus.
Taking a Hit: Asteroid Impacts and Evolution
Dr. David Morrison (NASA Ames Research Center)
Listen (mp3 file, 18.9 MB)
Asteroids have hit the Earth many time in the past, and they will continue to hit in the future, whether we are prepared or not. Collisions with our planet over 4.5 billion years have profoundly influenced the evolution of life. (In fact, were it not for the impact of a 15-km wide asteroid 65 million years ago, it is likely humanity would not be here.) Dr. Morrison, one of the world’s experts on the study of asteroid impacts, discusses the past and the future of these catastrophic hits, and explains how, in the last two decades, we have learned (in principle) how to defend ourselves. Unlike other natural hazards, we now have the capability of removing most of the impact risk within the next generation. However, the government still does not have a plan of action for when an asteroid is discovered heading our way or when an impact happens without any warning. (We recommend you listen to this podcast holding hands with someone you love.)