Lecture Archive 2010 (test)

Wednesday, January 06 2010 - 12:00 pm, PST Icy Bodies of the Outer Solar System: What Does The Spectroscopy Tell Us?
Dale Cruikshank

Spectroscopy, particularly in the near-infrared, continues to be the most effective means for determining the compositions of the surfaces of planetary bodies. Planetary spectroscopy has moved beyond the mere identification of species to the quantitative interpretation of mixtures of several materials and the physical states in which they occur. Dr. Cruikshank will show how spectra of Triton and Pluto show that methane is dissolved in solid nitrogen covering much of their surfaces, and wavelength shifts in carbon dioxide bands on Saturn's satellites show evidence of clathrate trapping of CO2 molecules in H2O ice cages.

slides

Wednesday, January 20 2010 - 12:00 pm, PST The EvoGrid: Building an Origin of Life Simulator & Its Implications for Life, the Universe and Everything
Bruce Damer

Bruce Damer will present the current state of the EvoGrid, a worldwide, multi-disciplinary project to simulate the chemical origin of life on Earth or as it might have occurred elsewhere in ours or other universes. When operational in 2010 the prototype EvoGrid will employ a central grid of computers to generate "digital primordial soups" and then, inspired by SETI, an even larger set of observer computers operating as @Home screen savers will be employed to look for signs of emergent complexity within the soups. While we are not expecting bona fide alien forms of digital life to emerge from the EvoGrid any time soon, the experiment will present long term profound implications for science, religion, and perceptions of our place in the universe. 

Wednesday, January 27 2010 - 12:00 pm, PST ESAS and the Augustine Commission: The Way Forward on US Manned Spaceflight
Daniel Rasky

 

 This talk will review the back drop and key findings for the Exploration Systems Architecture Study, pursued under former NASA Administrator Mike Griffin, and the recent Review of US Human Spaceflight Plans Committee headed by Norm Augustine. These two key studies have had, and will continue to have, significant impact on the course of the US space program. Possible directions for US manned spaceflight will be discussed as related to these studies and other important developments, such as the emergence of significant new commercial space companies and capabilities.

  download slidesslides

Wednesday, February 03 2010 - 12:00 pm, PST Mongolian and other Historic Solar Eclipses
Laurance Doyle

Dr. Doyle will discuss some simple solar and lunar eclipse observations (including a new one known as the "Emerald Tiara") as well as some of the historic eclipses that have occurred over the past several millennia, and what we have learned from them. Emphasis will be placed on special eclipse events -- eclipses that stopped wars, that proved the general theory of relativity, and so on. Dr. Doyle will spend some time discussing a special Mongolian eclipse that occurred in the 13th Century that helped to determine the modern rate of rotation of the Earth. Some Mongolian culture will be discussed -- since Dr. Doyle was recently on an eclipse expedition to Mongolia -- which will include Tovan throat singing.

 download slides slides
icon for view videoMongolian Throat Singing, courtesy of L. Doyle 

Wednesday, February 10 2010 - 12:00 pm, PST Observing String Multiverse with Astrophysical Black Holes
Sergei Dubovsky

One of the most intriguing and controversial recent ideas in cosmology and string theory is that the Universe is highly inhomogeneous on the length scales much longer than its currently observable part, with many of the fundamental "constants" of Nature varying on the ultra-long length scales. Our location in this cosmic landscape is to a large extent determined by requiring that the local particle physics parameters should allow for life to develop. Dr. Dubovsky will review the origin of these ideas and explain how they can be supported by the near future observations of astrophysical black holes. 

Wednesday, February 17 2010 - 12:00 pm, PST Asteroseismology in the era of CoRoT and Kepler space missions
Conny Aerts

After a general introduction into the research field of asteroseismology, we review the highlights achieved from multi-site ground-based campaigns dedicated to carefully selected targets. We show how asteroseismology has the potential to improve stellar evolution models to a level that cannot be achieved by any other method so far. Subsequently, we discuss several results from the operational French-led European space mission CoRoT (Convection, Rotation, planetary Transits) for various types of stars and illustrate the immense advantage of having long-term uninterrupted data from space with a factor 100 better precision compared to data from the ground. Finally, we will highlight the next step expected in this research, based on data assembled by the space mission Kepler (NASA) which has been designed primarily for exoplanet hunting. This mission, along with the future ESA PLATO satellite project, will allow us to do asteroseismology of numerous exoplanet host stars. 

Wednesday, February 24 2010 - 12:00 pm, PST The Habitability of the Phoenix Landing Site
Carol Stoker

Dr. Carol Stoker was a member of the Mars Phoenix Lander team that landed a robot in the polar regions of Mars. Dr. Stoker will present an analysis of results from the Mars Phoenix mission to the North Polar region of Mars that shows that conditions are probably habitable for life in modern times at this location. 

Wednesday, March 03 2010 - 12:00 pm, PST How to Build Cost-Optimized Interstellar Beacons (and How to Search for Them)
James Benford

How would we on Earth build galactic-scale Beacons to attract the attention of extraterrestrials? An optimum tradeoff emerges by minimizing the cost of producing power density at long range. James Benford will show scaling, examples and costs. If ETI were to build a cost-optimum interstellar Beacon, how should we look for it? Jim will propose SETI search strategies, a new test for SETI Beacons and describe how observers can differentiate Beacons from pulsars or other exotic sources.

download slides slides
more papers to download: http://arxiv.org/abs/0810.3964v2  http://arxiv.org/abs/0810.3966v2  http://arxiv.org/abs/1003.5938

Wednesday, March 10 2010 - 12:00 pm, PST Astrobiology of Basaltic glass in the oceanic basins: a source for early life nutrients?
Brad Bailey

Brad Bailey will explain how basaltic glass could be a source of energy and/or nutrients for early life. This has enormous Astrobiological implications as recent work has shown that Earth’s late heavy bombardment period would not have been energetic enough to completely sterilize the Earth’s surface and life may have been preserved through this period by residing within the deep crust. Fresh basaltic glass contains a significant amount of reducing potential and could therefore be a primary mechanism for providing energy to biological systems in addition to being a source for limiting nutrients such as phosphates. Ultimately, understanding the interplay between biological and geological systems will help us understand water-rock interactions and the global geochemical seawater budget. 

Wednesday, March 17 2010 - 12:00 pm, PDT What clays can tell us about past climate at Mawrth Vallis, Mars
Nancy McKeown

Mawrth Vallis has one of the largest exposures of phyllosilicates on Mars. Originally observed by OMEGA, CRISM has refined the detections and allowed positive identification of several phyllosilicate minerals including nontronite, montmorillonite, and kaolinite, as well as hydrated silica, based on their distinct spectral characteristics. The textures and morphologies of these units have been characterized using HiRISE imagery. Nancy McKeown will discuss the identification and mapping of these phyllosilicates and their implications for past climate at Mawrth Vallis.

Wednesday, March 24 2010 - 12:00 pm, PDT Exploring the Habitability of Icy Worlds: The Europa Jupiter System Mission
Bob Pappalardo

 NASA and ESA have recently selected the Europa Jupiter System Mission (EJSM) as the next Flagship mission to the out solar system. The mission concept consists of a NASA-led Jupiter Europa Orbiter (JEO) and an ESA-led Jupiter Ganymede Orbiter (JGO), which would execute a choreographed exploration of the Jupiter System before entering orbit around Europa and Ganymede, respectively. The mission's overall theme is: "The emergence of habitable worlds around gas giants," and JEO would focus on Europa with the goal: "Explore Europa to investigate its habitability." While the primary focus of JEO is to orbit Europa, the science return encompasses the entire Jovian system, especially as is relevant to the potential habitability of Europa. EJSM would shed new light on the potential habitability of icy worlds in our solar system and beyond. 

Wednesday, March 31 2010 - 12:00 pm, PDT Primordial Ice Reservoirs of the Solar System
David Jewitt

We now know that ice in the solar system resides in at least three distinct reservoirs, known as the Oort cloud, the Kuiper belt and the main-belt comets. Dr. Jewitt will discuss the nature, distribution and significance of the ice, highlighting its connection to the formation epoch, in a style intended to be sweeping and broadly accessible.

Wednesday, April 07 2010 - 12:00 pm, PDT Starship Life Support
Harry Jones

 Dr. Jones will report on the design and cost of a starship, with emphasis on life support systems. He will describe a multigenerational interstellar voyage to colonize a new planet. Nuclear propulsion is required. The mission is more feasible if a small crew travels slowly and lands with minimal equipment. Growing food is about as expensive as taking dehydrated food. Highly reliable life support can be achieved by providing spare parts and full systems. One small slow multigenerational interstellar voyage to colonize a new planet would cost about as much as the Apollo program. We can go to the stars! 

Wednesday, April 14 2010 - 12:00 pm, PDT Marine Biodiversity and Pretty Pictures: A Report from Indonesia's Raja Ampat
Mark Showalter

 When SETI astronomer Mark Showalter is not looking up at Saturn and its rings, he prefers to spend his time looking down, preferably through the viewfinder of his underwater camera. Mark will present a slide show from his recent visit to Raja Ampat, a remote dive site in Indonesia recognized as having the highest marine biodiversity of any place on Earth. 

Wednesday, April 21 2010 - 12:00 pm, PDT Titan: Outer-Planet Moon of Mystery
Jeff Moore

All landforms on Titan that are unambiguously identifiable can be explained by exogenic processes (aeolian, fluvial, impact cratering, and mass wasting). Previous suggestions of endogenically produced cryovolcanic constructs and flows have, without exception, lacked conclusive diagnostic evidence. Titan might be most akin to Callisto with weather. Dr. Moore will show the results of Landform Evolution Modeling for the purposes of testing this, and other, hypotheses. 

Wednesday, April 28 2010 - 12:00 pm, PDT PAHs and the Diffuse Interstellar Bands: From the Laboratory to Space
Farid Salama

The diffuse interstellar bands (DIBs) are absorption features that are seen toward reddened stars. They are caused by the absorption of light by the interstellar medium. Numbering hundreds of bands, the DIBs vary in strengths and in profiles and are detected in the near ultraviolet to the near infrared range. The bands are the signature of carriers that are ubiquitous in the interstellar medium making their identification an essential element for a correct understanding of the nature and the evolution of the interstellar medium. The diffuse bands have represented a long standing, fascinating challenge for astrophysics since they were first discovered more than a century ago. The search for the carriers of the DIB has motivated efforts at the frontiers of science, leading, among other things, to advances in spectroscopy and to the discovery of the fullerene molecules. Recent findings have shed light on the nature of the carriers of the DIBs and the role played by complex organic molecules in space. Recent progress in astronomical observations and in laboratory studies will be presented together with a discussion of the current consensus regarding this important issue. 

Wednesday, May 05 2010 - 12:00 pm, PDT Modeling the Effects of the Interstellar Medium on Engineered Signals of Extraterrestrial Origin
Dr. Samantha Blair

Dr. Blair will discuss the impairments that can be imposed on signals of technological origin traveling through the interstellar medium (ISM). The ISM contains ionized regions where fluctuations in the electron density have a significant effect on signals propagating through the medium. Techniques developed by pulsar researchers over the last 2-3 decades were used to characterize the impact of these effects on engineered as opposed to natural signals like pulsars, and in particular, seek insights into the types of signals to expect based on their susceptibility to ISM propagation impairments. 

Wednesday, May 12 2010 - 12:00 pm, PDT Kepler: Are There Any Good Worlds Out There?
Jon Jenkins

The Kepler Mission began its science observations just one year ago on March 12, 2009, initiating NASA’s first search for Earth-like planets. Initial results and light curves from Kepler are simply breath-taking, and they reveal as much about the instrument as they do about the stars Kepler observes. I will discuss how much we’ve learned over the past year about the instrument and the stars and how we are modifying the Science Pipeline to reveal small Earth-like planets. 

Wednesday, May 19 2010 - 12:00 pm, PDT ChemCam - the laser on the next Mars Lande
Jen Blank

Dr. Jen Blank is a member of the science team for ChemCam, a remote imager and Laser Induced Breakdown Spectroscopy (LIBS) remote analysis instrument. ChemCam will be able to determine elemental abundance of a rock up to 7 meters away by zapping it with a laser and detecting excited elemental lines. ChemCam is one of the instrument packages on the Mars Science Laboratory rover that will be launched to Mars next year. Landing site? Still TBD. Come along to hear about NASA's coolest new device for deciphering the geological story of The Red Planet.

Wednesday, May 26 2010 - 12:00 pm, PDT The Maunder Minimum: Astrophysical Connection to Climate Change
Dan Lubin

 The Maunder Minimum refers to an abrupt drop in solar luminosity of less than 1% during the mid-17th Century, which had profound impacts on global climate. We may be due for another solar "grand minimum" later this century. Dr. Lubin will discuss the implications of such a grand minimum during the era of anthropogenic global warming, and will also discuss astrophysical research efforts to determine how frequently a Maunder Minimum event occurs in nature. 

Wednesday, June 02 2010 - 12:00 pm, PDT Building a habitable planet: the physics and chemistry of planet formation
Monika Kress

 Habitable planets must not only reside in a narrow range of distances from their stars, but they also must contain water and carbon. This is easier said than done. In this talk, IDr. Kress will discuss the chemistry in protoplanetary disks, and the physical processes by which earth-like planets form. In particular, Dr. Kress will focus on how habitable planets obtain carbon and water, the key ingredients for life. 

Wednesday, June 09 2010 - 12:00 pm, PDT The Evolving Intersection of Physics and Biology
Jan Liphardt

 In April 1953, Watson and Crick largely defined the program of 20^th century biology: obtaining the blueprint of life encoded in the DNA. Fifty years later, in 2003, the sequencing of the human genome was completed. Like any major scientific breakthrough, the sequencing of the human genome raised many more questions than it answered. Dr. Liphardt will discuss some of the big open problems in cell and developmental biology, and he'll explain why approaches, tools, and ideas from the physical sciences are currently reshaping biological research. Super-resolution light microscopies are revealing the intricate spatial organization of cells, single-molecule methods show how molecular machines function, and new probes are clarifying the role of mechanical forces in cell and tissue function. At the same time, Physics stands to gain beautiful new problems in soft condensed matter, quantum mechanics, and non-equilibrium thermodynamics.  

Wednesday, June 16 2010 - 12:00 pm, PDT Don't Rain on my Planet: The Importance of Clouds and Hazes for Understanding Exoplanets and Brown Dwarfs
Mark Marley

Clouds and hazes shape the observed spectra of exoplanets and brown dwarfs. Yet we know from Earth that clouds and hazes are inherently difficult to model and are the leading source of uncertainty in terrestrial GCM forecasts of globals warming. Dr. Marley will review what we know about the chemistry and physics of clouds in substellar atmospheres and discuss some pathways to haze formation in exoplanet atmospheres. In the future determining if extrasolar earthlike planets are habitabl-or inhabite-will ultimately depend on an understanding of the role clouds play in their atmospheres, so we can expect to be hearing about these issues for some time to come. 

Wednesday, June 23 2010 - 12:00 pm, PDT Cosmic Microwave Background Measurements with the QUaD Experiment
Sarah Church

The Cosmic Microwave Background (CMB) radiation has enabled us to probe conditions in the early universe with incredible precision. The QUaD experiment is one of the first to report detailed measurements of the polarization of the CMB, which provides extra information that complements temperature measurements. Dr. Church will discuss the implications of the QUaD data and set the stage for what we can expect from future, more sensitive experiments. 

Wednesday, June 30 2010 - 12:00 pm, PDT The Hayabusa Re-entry Observation Campaign
Peter Jenniskens

Dr Peter Jenniskens recently led a campaign in a NASA DC-8 aircraft to observe the reentry of the Japanese asteroid-hunting Hayabusa spacecraft in the Australian Outback. The international team collected awesome footage of the break-up of the spacecraft and the intact sample pod. Dr. Jenniskens will describe the organisation of the expedition and the first results of the observations.

link: http://airborne.seti.org/hayabusa/

Wednesday, July 07 2010 - 12:00 pm, PDT Did the Late Heavy Bombardment end with a whimper? Evidence from 3.5-3.2 Ga rocks in Archean Barberton region of South Africa
Don Lowe

 Lunar evidence of Late Heavy Bombardment has been interpreted to suggest that large-body impacting declined rapidly after about 3.8 Ga and that by 3.5 Ga the terrestrial bombardment rate was not much greater than the impact rates of today. In 1986 and 1989 Dr. Lowe and colleagues described four major layers of spherical particles in the 3.22-3.55 Ga Barberton greenstone belt (BGB), South Africa, ranging from 3,472 to 3,243 Ma, and interpreted them to represent the products of large terrestrial impacts of bolides 20-50 km in diameter. Since describing and interpreting these early impact layers, they have identified at least three additional thick layers of spherules in the Barberton belt that likely represent deposits of large impacts, and two new layers that display some geological features associated with impacts. Large impact layers have been identified to date in most of the major sedimentary units in the BGB. Intervening sections are composed largely of volcanic rocks where the record of impact events is unlikely to be preserved: it seems likely that other large impacts occurred during this period without leaving a record. These layers suggest that Earth continued to be bombarded by large extraterrestrial objects late into the Archean, at least until 3.2 Ga. The large sizes possible for these objects means that, while none was probably a sterilizing impact, many may have severely heated the oceans and atmosphere, boiled off the upper layer of seawater. The 3.8-3.2 Ga development of the Earth's surface environment and life may have been constrained largely by the continuing flux of large impactors. Only as that flux declined in the Late Archean were stable surface systems established within which non-thermophilic organisms and a stable geodynamic system could develop and evolve. 

Wednesday, July 14 2010 - 12:00 pm, PDT Understanding the Star Formation Rate
Mark Krumholz

Stars are the engines of the Universe: nuclear reactions within them are the only significant source of non-gravitational power in the cosmos, the source of all heavy elements, and the cradles of life. However, the process by which stars form remains poorly understood, and one mystery in particular stands out: what sets the star formation rate? In this talk Dr. Krumholz will review our understanding of the rate at which stars form, both observationally and theoretically. 

Wednesday, July 21 2010 - 12:00 pm, PDT From Hot Jupiters to Super-Earths: A Survey of Exoplanetary Atmospheres
Heather Knutson

The past decade has marked a period of great progress in our quest to discover and characterize the properties of the planets outside of our own solar system. Observations of transiting systems, in which the planet periodically passes in front of and then behind its star as seen from the earth, have allowed us to study the properties of these distant worlds in unprecedented detail. Dr. Knutson will describe some of our initial measurements of the close-in, gas giant planets known as hot Jupiters, and discuss how these same techniques might be applied to smaller and more earth-like worlds. 

Wednesday, July 28 2010 - 12:00 pm, PDT Exploring Mars for evidence of habitable environments and life
Dave Des Marais

Recent Mars missions have discovered fascinating landscapes as well as chemicals and minerals formed by the action of liquid water. Mars could have been habitable sometime in the past, and liquid water might persist in some subsurface environments today. Dr. Dave Des Marais, Chair of the Mars Exploration Program Advisory Group (MEPAG), will discuss recent discoveries that are helping to identify the most promising places to search for evidence of life. 

Wednesday, August 04 2010 - 12:00 pm, PDT Titan Unveiled
Ralph Lorenz

 Saturn's giant moon Titan has been of considerable interest since the presence of an atmosphere was hinted at one century ago. The NASA-ESA-ASI Cassini-Huygens mission, at Saturn for the last 4 years, has transformed this curious dot in the sky into a remarkably diverse, complex and interesting world, which is in many ways more Earth-like than anywhere in the solar system. This talk will summarize some of Cassini's recent findings with emphasis on the interactions between Titan's surface, atmosphere, and interior. These include dune-covered sand seas, river channels that attest to violent but perhaps rare downpours and climate change, hydrocarbon lakes and possible cryovolcanic features. The rich inventory of organics on Titan makes it a particularly appealing target for astrobiological studies.
Titan's thick atmosphere and low gravity permit a wide range of exploration vehicle types, notably aircraft and balloons. The scientific goals and technical features of vehicles and instruments for future exploration of Titan, will be discussed. 

Wednesday, August 11 2010 - 12:00 pm, PDT 2010 REU Students' 3-Minute Presentations
Wednesday, August 18 2010 - 12:00 pm, PDT From Earth to the Stars: Psychological Issues during Space Missions
Nick Kanas

Recent studies on-orbit have provided information on important psychological and interpersonal issues that affect crewmembers and mission control personnel who are involved with near-Earth space missions. However, the extreme distances, communication delays, and increased crewmember autonomy that will characterize missions to Mars and beyond will introduce additional psychosocial stressors never before experienced. Professor Kanas will discuss these stressors and their impact on people traveling to the outer solar system and nearby stars, including those resulting from new technologies, such as traveling at a significant fraction of the speed of light, putting crewmembers in suspended animation, or creating giant self-contained generation ships of colonists who will not return to Earth. Professor Kanas is the author of two books: Space Psychology and Psychiatry and Star Maps: History, Artistry, and Cartography

Wednesday, August 25 2010 - 10:19 am, PDT Beyond Kepler: Direct Imaging of Earth-like Planets
Ruslan Belikov

Is there another Earth out there? People have been asking this question for over two thousand years, and we finally stand on the verge of answering it. The Kepler mission (which was featured in several of the past SETI talks) will likely find the first ever Earth-sized planet around the habitable zone of another star. This talk is about the next step after Kepler, which might be a mission to directly image Earth-like planets and analyze their spectra for biomarkers such as oxygen, water, and atmosphere. The talk will cover the technology of direct planet imaging, focusing on the work done at NASA Ames, as well as the science we might get out of it and some repercussions. 

Wednesday, September 01 2010 - 12:00 pm, PDT Free Electron Laser Communication with Exoplanets and Other Space Applications
Bill Colson

The U.S. Navy is developing a Free Electron Laser with MW-level average output power, as reported in a recent National Academy Report.*  Several scientific space applications appear to be interesting and feasible, including power beaming to satellites, space stations, or space vehicles.  New proposals also include scientific investigation of the moon and nearby planets using an FEL stationed on earth, but capable of illuminating small areas of these objects with light spectrally brighter than the sun, permitting direct observations at tunable, selectable wavelengths.  It also appears possible to use such an FEL to send detectable signals out to 50 light-years or more, conceivably providing communications capability across such distances.  Invoking the concept of reciprocity, it could be we should be looking for such signals from intelligent civilizations on exoplanets.  A plan for such exploration is suggested.
* Scientific Assessment of High-Power Free Electron Laser Technology, National Academy of Sciences, Board on Physics and Astronomy Report (2009)

Wednesday, September 08 2010 - 12:00 pm, PDT NASA's Flexible Path Architecture Study for Human Missions
David Korsmeyer

NASA supported the "Review of U.S. Human Spaceflight Plans" (HSF) Committee during the Summer of 2009 by performing a study and analysis of a novel Flexible Path concept. The Flexible Path architecture for human spaceflight calls for incrementally more aggressive human missions out into the inner solar system. Exploration of the Moon, Lagrange points, Near Earth Objects, leading to the exploration of the Martian moons. All of these missions would have broad technical and scientific merit as precursors to the future exploration of the Mars surface. Dr. Korsmeyer lead the Flexible Path Architecture Study for NASA in support of the HSF Committee.

Wednesday, September 15 2010 - 10:24 am, PDT From the Earth to Mars: Lessons for Mars Science and Exploration from the Haughton-Mars Project, Devon Island, High Arctic
<iframe width="560" height="349" src="http://www.youtube.com/embed/nJWinS8fi-8" frameborder="0" allowfullscreen></iframe>Pascal Lee

The Haughton impact crater site on Devon Island, High Arctic, is one of the most Mars-like places on Earth. Since 1997, the Haughton-Mars Project (HMP) has been conducting science and exploration research at the site, and established the HMP Research Station, now the largest privately operated polar research station in the world. Geology and astrobiology investigations have led to the formulation of the “Mars, Always Cold, Sometimes Wet” Model. Dr. Lee will describe how Haughton is being used to conduct exploration investigations which are helping pave the way towards the first human mission to Mars.

Wednesday, September 22 2010 - 12:00 pm, PDT Titan: Past, Present and Future
Chris McKay

The results of the Cassini/Huygens mission raise many questions about the source and fate of methane on Titan. Understanding the methane cycle on Titan is key to understanding its past history and future evolution and provide a context for considering life on Titan that uses methane for its biological solvent. Dr. McKay, a member of the Huygens science team, will describe a new model for Titan's geological cycle that may indicate it's current thick atmosphere is a transient phenomenon.

Wednesday, September 29 2010 - 12:00 pm, PDT Lakes on Mars: Their Past, Present, and Future Exploration
Nathalie Cabrol

Lakes are time capsules. On Earth, they are considered sentinels of climate change and may have played the same role on early Mars. Their basins capture the record of geological and environmental fluctuations over a wide range of temporal and spatial scales. Terrestrial lakes host a diversity of habitats where life’s adaptability can be pushed to the edge in often unstable environments. They preserve the evidence of ancient life as sedimentation rapidly entombs dead organisms and generates anoxic conditions favoring the formation of fossils. This makes them prime candidates for exploration. The existence of lakes on ancient Mars is now widely accepted but that was not always the case. The history of science shows that knowledge on any scientific question is shaped by the means of exploration and those means are molded by what we think the world is. Prior to Mars Global Surveyor, the relatively low resolution of orbital imagery made it difficult to confirm Martian paleolakes by direct observations, though their existence was inferred because valley networks had already been identified on Viking and Mariner 9 images. Interpretation rested on ambiguous morphological evidence at 200 m/pixel on average with only localized coverage at higher resolution. Today, high-resolution imagery, morphology, geology, and mineralogy converge to support the existence of ancient standing bodies of water on Mars. This evidence is collectively examined by 33 authors and co-authors in the first monograph on the subject entitled /Lakes on Mars/, a book to be published by Elsevier, September 3, 2010 (Nathalie A. Cabrol and Edmond A. Grin, Eds). Here, Dr. Nathalie Cabrol will discuss the evidence presented in the book, its environmental significance in terms of climate and habitability, and the questions it still raises.

Wednesday, October 06 2010 - 12:00 pm, PDT The Mars dichotomy: Brought to you by a mega impact
Margarita Marinova

One of the largest features on Mars is its hemispheric dichotomy: the difference in crater density, elevation (~4 km), and crustal thickness (~30 km) between the Northern Lowlands and the Southern Highlands. Recent impact cratering simulations show that the ~10,000 km diameter Lowlands can be formed by a single large impact. This impact size was common at the end of planetary accretion and falls in the planetary-scale impact size regime, in which the curvature and radial gravity of the planet are important. Dr. Marinova will discuss the implications of her research into the puzzling Martian hemispheric dichotomy.

Tuesday, October 12 2010 - 12:00 pm, PDT Arecibo Radar Observations of Near-Earth Asteroids
Ellen Howell

Radar observations are one of the only groundbased techniques to spatially resolve near-Earth asteroids. Images with up to 7.5-m resolution reveal a wide variety of shapes, surface features and helped to discover many binary objects. Our understanding of the nature and evolution of NEAs has changed radically in recent years, in a large part due to the information from radar images, and shape models derived from them. I will discuss current results and upcoming improved capabilities of the Arecibo planetary radar system.

 

slides: HowellArchive.zip

Wednesday, October 13 2010 - 12:00 pm, PDT A New look at what Life is and how it began
Nick Woolf

Life has two unique processes. The first is precision assembly, in which the shape of a molecule is selected, and it is “glued” to another precisely selected molecule. The second is when the assembler-glue-selector device exactly copies itself. The first item produced must be a structure so as to be survival-selected. In turn this selection needs to have the eventual effect of selecting the assembler-glue-selector. The system requires the development of two different polymers, one for structures, the other for information transfer. During the development of this precision, the proto-life is sustained by a dissipative process. It is explored why the assembler-glue-selector becomes RNA and ATP. Nitrogen provides the key NH bonds that are broken for “gluing” in both nucleic acids and amino acids. The requirements for the process, abundant availability of the nitrogenous organic materials from space, freshwater for the origin of membranes, and high temperatures and pressures for natural condensation reactions seem to uniquely select terrestrial geyser regions about 4.4 Gy ago as the site of the origin of terrestrial life.

Wednesday, October 20 2010 - 12:00 pm, PDT Dark Matter: The Other Universe
Chung-Pei Ma

A startling discovery in science in the past few decades is most mass in the universe is in "dark matter"- some very clever form of matter capable of speeding up the motion of stars and galaxies while eluding direct detection at the same time. Dr. Ma will summarize the evidence for the existence of dark matter, discuss what it can and cannot be, and describe ongoing research on this mysterious component of the universe.

Wednesday, October 27 2010 - 12:00 pm, PDT New Search Strategies for SETI
Seth Shostak

SETI continues to embroider the search strategy pioneered by Frank Drake, a half-century ago. Although the technology of the search has enormously improved, are we being too conservative in our choice of targets? In this talk, we'll consider some of the other places we might look for ET.

Wednesday, November 03 2010 - 12:00 pm, PDT Computer simulations of convection and magnetic field generation in planets
Gary Glatzmaier

Dr. Glatzmaier will describe his studies of fluid flows and the magnetic fields they generate in the electrically conducting interiors of terrestrial planets, like the Earth, of giant planets, like Jupiter, and of satellites, like Europa, that orbit around giant planets. Dr. Glatzmaier develops computer models that solve a set of coupled nonlinear differential equations that describe the main physics of the problem in order to simulate the 3D time-dependent evolution of the flows and fields. He will show computer graphical movies of several simulations and discuss what we learn from them.

Wednesday, November 10 2010 - 12:00 pm, PST Statistical Equation for Habitable (SEH) and the Statistical Fermi Paradox
Claudio Maccone

In this lecture Dr. Maccone will provide a statistical equation that we call Statistical Equation for Habitables (SEH) as well as its relationship to the Statistical Fermi Paradox. He will start by noting that the statistics of habitable planets may be based on a set of ten (and possibly more) astrobiological requirements first pointed out by Stephen H. Dole in his book “Habitable planets for man” (1964). He will then provide the statistical generalization of the original (too simplistic) Dole equation by replacing a product of ten positive numbers by the product of ten positive random variables. This is called the “Statistical Equation for Habitables” or SEH. His proof is based on the Central Limit Theorem (CLT) of Statistics, stating that the sum of any number of independent random variables, each of which may be arbitrarily distributed, approaches a Gaussian (i.e. normal) random variable (Lyapunov form of the CLT). Dr. Maccone will then discuss the implications of this derivation, including a practical example of how the equation can be used to find the average distance between Habitables. Finally, this result will in turn be used to discover the statistical extension of the Fermi Paradox, namely the Fermi paradox re-read in terms of probability distributions.

Wednesday, November 17 2010 - 12:00 pm, PST Status of the James Webb Telescope and its Capabilities for Exoplanet Science
Mark Clampin

The James Webb Space Telescope (JWST) is a large aperture (6.5 meter), cryogenic space telescope with a suite of near and mid-infrared instruments covering the wavelength range of 0.6 µm to 28 µm. JWST’s primary science goal is to detect and characterize the first galaxies. It will also study the assembly of galaxies, stellar and planetary system formation, and the formation and evolution of planetary systems. Dr. Clampin will review the design of JWST, and discuss the current status of the project, with emphasis on recent technical progress in the construction of the observatory. He also review the capabilities of the observatory for observations of exosolar planets by means of transit photometry and spectroscopy, direct coronagraphic imaging, and high contrast imaging and spectroscopy. He will discuss the current predictions for the performance of the observatory, with special reference to the demands of exoplanet science observations.

Wednesday, December 01 2010 - 12:00 pm, PST IRIS: a new window on the physics of the solar interface region
Bart De Pontieu

The Sun's outer atmosphere or corona is heated to millions of degrees, considerably hotter than its cool surface or photosphere. Explanations for this long-standing enigma typically invoke the deposition in the corona of non-thermal energy generated by the interplay of convection and magnetic fields. However, the exact physical mechanism driving coronal heating remains unknown. During the past few years, recently built instruments like the Japanese Hinode satellite, the Swedish Solar Telescope in Spain and NASA's Solar Dynamics Observatory (SDO) combined with advanced numerical simulations have revealed a new window into how the Sun's atmosphere is energized. These results directly challenge current theories and highlight the importance of the interface region between the photosphere and corona for understanding how the solar atmosphere is heated. Dr. De Pontieu will present some of these results and describe how NASA's recently selected Interface Region Imaging Spectrograph, which is being built by Lockheed Martin's Solar and Astrophysics Laboratory in Palo Alto, in collaboration with NASA Ames, Smithsonian Astrophysical Observatory (SAO), Montana State University, Stanford University and the University of Oslo, will be able to address many of the outstanding issues and problems.

Wednesday, December 08 2010 - 10:42 am, PST Microbial Dark Matter in Glacial Ice and implications for Martian life
P. Buford Price

Life may have arisen independently on both Mars and Earth, may survive in subsurface niches on Mars, and may manifest itself via emission of gases such as methane. Microbes adapted to life in ice at low temperatures metabolize at a rate many orders of magnitude lower than their rate for exponential growth. Life in solid ice survives either until nutrients and bioelements are consumed or until alpha-particles from U and Th in the ice induce too many double-strand breaks. Our studies with scanning fluorimetry of ice cores and flow cytometry of microbes in melted ice have shown that Prochlorococcus, the dominant phototroph in the ocean, is also the dominant phototroph in Antarctic ice. Dr. Price will talk about the story of how this bacterium came to be discovered in ice and how changes in its tiny genome as a function of its depth may enable its evolution to be followed over up to a million generations.

Wednesday, December 15 2010 - 12:00 pm, PST Bringing a Chemical Laboratory Named Sam to Mars on the 2011 Curiosity Rover
Paul Mahaffy

Dr. Mahaffy is the Principle Investigator for the SAM analysis suite on Mars Science Laboratory Rover (Curiosity). An important goal of upcoming missions to Mars is to understand if life could have developed there. The task of the Sample Analysis at Mars (SAM) suite of instruments and the other Curiosity investigations is to move us steadily toward that goal with an assessment of the habitability of our neighboring planet through a series of chemical and geological measurements. SAM is designed to search for organic compounds and inorganic volatiles and measure isotope ratios. Other instruments on Curiosity will provide elemental analysis and identify minerals. Dr. Mahaffy will discuss how SAM will analyze both atmospheric samples and gases evolved from powdered rocks that may have formed billions of years ago with Curiosity providing access to interesting sites scouted by orbiting cameras and spectrometers.