Silicon Valley Astronomy Lectures
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.)
A Ringside Seat to the Formation of Planets
Dr. Dana Backman (SETI Institute and Astronomical Society of the Pacific)
Listen (mp3 file, 19.8 MB)
Astronomers have discovered dusty “doughnuts” of cosmic raw material around many younger stars. In some cases, astronomers can see tantalizing hints in the rings that planets may be forming or may already have formed from this material. Dr. Backman explains how new kinds of telescopes and observations are making it possible for us to detect the birth process of planets around nearby stars. He concludes by previewing future observations of these intriguing dusty rings with upcoming telescopes, particularly the SOFIA (Stratospheric Observatory for Infrared Astronomy) Project in which NASA has outfitted a 747 plane with a telescope that can observe heat-rays from distant objects.
Comparing Worlds: Climate Catastrophes in the Solar System
Dr. David Grinspoon (Denver Museum of Nature and Science)
Listen (mp3 file, 22.3 MB)
Take an entertaining and enlightening journey with an astronomer and popular author through the history of our solar system, discovering runaway greenhouses and snowball planets. Compare the evolution of Venus, Earth, and Mars over the years. And learn how studying the evolution of other planets can help us understand and predict climate change on Earth.
A Scientist in Space and Searching for Earth-like Planets: NASA’s Kepler Mission
Dr. Janice Voss (NASA Ames Research Center)
Listen (mp3 file, 17.5 MB)
Dr. Voss, who has logged 49 days in space (traveling almost 19 million miles in 779 Earth orbits) discusses her work in space and what it’s like flying on the Shuttle as a scientist. She then talks about NASA’s upcoming Kepler mission, which will use a telescope in space to search for “transits” — when a planet orbiting another star moves in front of its star and blocks its light. Although a planet might only block a tiny fraction of the light from a star, that decrease in brightness is enough to give a clear signal that the planet is there. With this mission, scientists hope to be able to find not only Jupiter and Saturn-sized planets, but also those as small as Earth. At the end, Dr. Voss answers a number of audience questions about both aspects of her work.
Glimpsing the Edge of the Universe: Results from the Hubble Space Telescope
Dr. Bruce Margon (University of California, Santa Cruz)
Listen (mp3 file, 24 MB)
The Hubble Space Telescope has circled the Earth 15 times every day for more than 16 years. Dr. Margon, who was until recently the Associate Director for Science for the Hubble, describes the most important discoveries made with the telescope and how it can show us new details of the universe from the solar system to the most distant reaches of space. In addition, he briefly discusses the future of the Hubble and some interesting public reactions to it.
The Planet Pluto: Maligned but Not Forgotten
Dr. Dale Cruikshank (NASA Ames)
Listen (mp3 file, 20.3 MB)
Dr. Cruikshank reviews what we knew about Pluto (including its atmosphere, of which he was the co-discoverer), why Pluto was re-classified as a dwarf planet in the fall of 2006, and what the New Horizons spacecraft may reveal about this distant world in the next decade.
Dark Energy and the Runaway Universe
Dr. Alex Filippenko (University of California, Berkeley)
Listen (mp3 file, 24.7 MB)
In 1998, observations of very distant exploding stars provided intriguing evidence that the expansion of the Universe is speeding up with time, rather than slowing down due to gravity as expected. Today, new and completely independent observations strongly support this amazing conclusion. Over the largest scales of space, our Universe seems to be dominated by a repulsive “dark energy,” stretching the very fabric of space itself. Dr. Filippenko, who is a leader in the group that has made some of these remarkable observations, gives us a progress report on our “runaway universe” and then answers a host of audience questions about the overall behavior of the universe.