CSC/SETI Institute Colloquium Series 2010

January 17, 2010

Modeling the Effects of the Interstellar Medium on Engineered Signals of Extraterrestrial Origin.

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.

SETI Archive: http://www.seti.org/talks

Kepler: Are There Any Good Worlds Out There?

Jon Jenkins, SETI Institute

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.

SETI Archive: http://seti.org/talks

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.

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Building a habitable planet: the physics and chemistry of planet formation

Monika Kress, Department of Physics and Astronomy, San Jose State University

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.

SETI Archive: http://seti.org/talks

The Evolving Intersection of Physics and Biology

Jan Liphardt, UC Berkeley Physics Department

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.

SETI Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

Cosmic Microwave Background Measurements with the QUaD Experiment

Sarah Church, Deputy Director of KIPAC, Stanford University

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.

SETI Talks archive: http://seti.org/talks

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.

SETI Talks Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

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.

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SETI Archive: http://seti.org/talks

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.

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SETI Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

The Research Experience for Undergraduates Summer Class of 2010 present their work in a short, 2 minute format. A variety of very interesting topics are covered!

SETI Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

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)

SETI Archive: http://seti.org/talks
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.

SETI Archive: http://seti.org/talks
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.

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.

SETI Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

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.

SETI Archive: http://seti.org/talks

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. Dr. Howell will discuss current results and upcoming improved capabilities of the Arecibo planetary radar system.