SETI Institute Weekly Colloquium - Upcoming Speakers
Pressurized rovers are airtight all-terrain motorhomes in which future planetary explorers will live, work, sleep, and drive during multiple-day excursions far away from their home base. Although pressurized rovers are commonly featured in science-fiction lore and technical studies on paper, there is still very little practical experience with the use of such vehicles in terrestrial field exploration. Since 2003, the NASA Haughton-Mars Project (HMP) has begun leading a series of field simulations of planetary pressurized rover traverses on Devon Island, High Arctic, a bleak and barren polar analog often described as Mars On Earth. As stand-ins for pressurized rovers, the HMP uses specially modified Humvees equipped with living quarters, satellite comms & nav systems, robotic arms, and spacesuit ports. Rover traverses at HMP are also set in a true field exploration operations environment in which dangers, while not as unforgiving as on Mars, are nevertheless real and relevant.
This talk summarizes the HMP’s experience with simulated pressurized rover treks to date, and lessons learned for planning future road trips on the Moon or Mars. Focus is placed on the HMP’s Northwest Passage Drive Expedition (2009-2011), an epic rover journey from the continental United States to Mars On Earth, across hundreds of kilometers of sea-ice along the fabled Northwest Passage. During the voyage, the expedition crew encountered conditions and challenges analogous in basic ways to those awaiting future pressurized rover crews on Mars: hostile environment, dust storm-like blizzards, uncertain route, treacherous terrain, equipment failure, tight crew quarters, limited resources, remoteness, and isolation.
While pressurized rover treks will dramatically expand the range and productivity of human planetary exploration, they will remain expeditions within an expedition. If not planned and implemented with care, they will quickly spell doom for their crews.
We are poised to take advantage of a remarkable confluence of technological advances and scientific opportunity. For the first time, very fast, wide bandwidth, high-gain, low noise near-infrared avalanche photo diode (APDs) detectors are available and reasonably priced. Dr. Wright and her team are designing and constructing a new SETI instrument to search for direct evidence of interstellar communications via pulsed laser signals at near-infrared (900 - 1700 nm) wavelengths. The new instrument design builds upon our past optical SETI work, and is the first step toward a new, more versatile, and more sophisticated generation of very fast optical and near-infrared pulse search devices. Dr. Wright will discuss the advantages of SETI searches at near-infared wavelengths. Dr. Wright will also present the instrument layout, including an overview of the opto-mechanical design, detector selection and characterization, signal processing, and integration procedure. Finally, she will describe our initial observational setup and search strategies for SETI targets and other astronomical studies.
Informed by comparative planetology and a survey of the major episodes in Earth history, Dr. Grinspoon will offer a taxonomy of planetary catastrophes meant to illuminate the unusual nature of the “Anthropocene”, the current epoch of human-driven planetary-scale changes, and reframe our current environmental and technological predicaments as part of a larger narrative of planetary evolution. This saga has now reached the pivotal moment when humans have become a dominant force of planetary change, and geological and human history are becoming irreversibly conjoined. Is this a likely or even inevitable challenge facing other complex life in the universe? Possible implications for exoplanet characterization and SETI will be considered, as well as the choices our civilization faces in seeking to foster a wisely managed Earth.
While the Curiosity mission to Mars is not designed to test for life past or present, it is very much involved in determining whether Mars could have once supported life. And the answer coming back from Gale Crater is an unequivocal "yes." The Curiosity team determined that at Yellowknife Bay, but is continuing and broadening its search for habitable environments at Mount Sharp. The question now front and center is whether that habitability was local to Gale or may well have been widespread. Adding to the sense of exciting progress in the likely identification of Martian organic material at Gale -- what would be a first if fully confirmed. And as a backdrop to the search for life and life-supporting habitats on Mars is the understanding that if signs of ancient and distinctly Martian life are found, then the case for a universe filled with life increases dramatically.
Dark Matter remains a profound mystery at the intersection of particle physics, astrophysics, and cosmology. One of the leading candidates, the Weakly Interacting Massive Particle, or WIMP, may be detectable using terrestrial particle detectors. Recent technological advances are enabling very rapid increases in sensitivity in the search for these particles. I will talk about the LUX experiment, a liquid xenon time projection chamber, which currently holds the best upper limit over much of the WIMP mass range. I will also discuss plans for a larger follow up experiment, LZ, which will just begin to measure a background neutrino signal that will set a fundamental limit our ability to search for WIMP dark matter.
The Yellowstone Plateau Volcanic Field is characterized by extensive seismicity, episodes of uplift and subsidence, and a hydrothermal system that comprises more than 10,000 thermal features. Some of the recent advances include more refined geophysical images of the magmatic system, characterization of fluid sources and water-rock interactions, quantitative estimates of heat and magmatic volatile fluxes, discovering and quantifying the role of thermophile microorganisms in the geochemical cycle, defining possible links between hydrothermal activity, deformation, and seismicity; quantifying the dynamics of geyser eruptions, and the discovery of extensive hydrothermal activity in Yellowstone Lake.
Saturn's ring system is an astrophysical disk that is neither light-years away nor billions of years in the past. We can visit this disk at close range and observe a number of phenomena that also operate in disks of other kinds. As a result, we see small-scale processes that shape ring texture, connect those processes to the bodies and structures that cause them, and watch closely as the disk changes with time. We will discuss recent Cassini observations that elucidate disk processes including 1) "self-gravity wakes" and "spiral density waves," both of which were originally proposed for galaxies but are observed with exquisite precision in Saturn's rings, 2) "propeller" features caused by 100-meter to km-sized moonlets embedded in the disk; these are the first objects ever to have their orbits tracked while embedded in a disk, rather than orbiting in free space, and hold the potential of deepening our understanding of planetary migration, and 3) irregular edge shapes in the gaps opened up by larger moons (10 km and more), which may hold clues to angular momentum transport.