Currently viewing the tag: "Talks"
In honor of the arsenic-loving microbe GFAJ-1 that lives in Mono Lake, California, here’s a clip from the documentary, A Life’s Work. For more on this story, go to: alifesworkmovie.com
SETI Talks Archive: seti.org 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.
SETI Talks Archive: seti.org In late 2006, NASA’s Constellation Program (CxP) sponsored a study to examine the feasibility of sending a piloted Orion spacecraft to a near-Earth Object (NEO). One of the significant advantages of this type of mission is that it strengthens and validates the foundational infrastructure of the United States Space Exploration Policy and his highly complementary to NASA’s planned lunar sortie and outpost missions circa 2020. Rob Landis will discuss how human expedition to a NEO would not only underline the broad utility of the Orion Crew Exploration Vehicle (CEV) and Ares launch systems, but would also be the first human expedition to an interplanetary body beyond the Earth-Moon system.
SETI Talks Archive: seti.org 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 Talks Archive: seti.org Extra dimensions of space may be present in our universe. Their discovery would dramatically change our view of the cosmos and would prompt many questions. How do they hide? What is their shape? How many are there? How big are they? Do particles and forces feel their presence? This lecture will explain the concept of dimensions and show that current theoretical models predict the existence of extra spatial dimensions which could be in the discovery reach of present and near-term experiments. The manner by which these additional dimensions reveal their existence will be described.
Is there alien life in the universe – or does it only exist in science fiction? Dr. Seth Shostak, the Chief Astronomer for SETI (the Search for Extra Terrestrial Intelligence) gives a funny and candid look on our fascination with aliens, and the real world efforts by SETI to find extra terrestrial life. Dr. Shostak looks both at our history of “looking for ET” as well as the current and future potential for first contact. Dr. Shostak’s speech was sponsored by the Beyond Center, an institute with the College of Liberal Arts and Sciences at Arizona State University.
SETI Talks Archive: seti.org 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 Talks Archive: seti.org 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.
SETI Talks Archive: seti.org Richard Muller and his collaborators have recently analyzed the most complete record of marine animal fossils ever compiled, the “Compendium” of Jack Sepkoski, which lists all known fossil marine animal genera back 542 million years. When the fossil diversity (number of distinct genera) is plotted, it shows a very strong 62 Myr cycle. The cycle is particularly evident in the species that endured for relatively short times, as shown in the diagram below (published in Nature, vol 434, 208-210, 10 March 2005).
SETI Talks Archive: seti.org 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.
SETI Talks archive: seti.org 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.