SETI Institute Weekly Colloquium - Upcoming Speakers
Abstract: Dark energy is a phenomena causing the Universe to expand more rapidly than can be explained by Einstein's laws of gravity. Its discovery merited the 2011 Nobel Prize in Physics. The effects of dark energy imprint on large galaxy maps.
The Baryon Oscillation Spectroscopic Survey (BOSS) on the Sloan Telescope has
mapped 200 million galaxies in 2-D, and 1.5 million galaxies and quasars
in 3-D. We measure the scale of the universe to percent-level precision at
redshifts z=2.4, z=0.6 and z=0.3, from the deceleration to acceleration
driven by dark energy. Recent maps are consistent with the "simplest"
modification of Einstein's laws, the additional of a cosmological constant.
Dr. Zee will talk about a proposal that a sufficiently advanced civilization may employ Cepheid variable stars as beacons to transmit all-call information throughout the galaxy and beyond. They might employ a pulsed neutrino beam to trigger the expansion of a Cepheid at an earlier than normal time, generating a binary signature of normal period or artificially shortened period.
One can construct many scenarios wherein it would be desirable for such a civilisation of star ticklers to transmit data to anyone else within viewing range.
The beauty of employing Cepheids is that these stars can be seen from afar (we monitor them out through the Virgo cluster), and any developing technological society would seem to be likely to closely observe them as distance markers. Records exist of Cepheids for well over 100 years. We propose that these (and other regularly variable types of stars) be searched for signs of phase modulation (in the regime of short pulse duration) and patterns, which could be indicative of intentional signalling.
Abstract: Like the Earth, Mars experiences seasonal cycles due to its ~25-degree
axial tilt. Unlike the Earth, polar winter on Mars brings temperatures
cold enough to freeze out the atmosphere, in the form of carbon dioxide
surface frosts and snowfalls. The ice caps of Mars grow and shrink in
response to seasonal changes in the polar heat balance. Since 2006, we
have been monitoring the martian polar regions with multi-spectral thermal
infrared measurements acquired by the Mars Climate Sounder (MCS). From
these data, we retrieve vertical profiles of temperature and aerosol
opacity, as well as surface properties such as ice granularity and dust
content. This dataset provides an unprecedented view of the rich and
complex ice caps and polar atmosphere. In this talk, I will highlight the
dynamic polar processes at the heart of the martian CO2 cycle, as revealed
by MCS. We will see evidence for striking inter-annual repeatability,
diverse thermal and precipitation regimes, and intense localized
snowstorms. In light of these new observations, we will explore the
implications for the present and past climate of Mars.
The International Space Station is a US taxpayers investment estimated at about $70 billion spent over 30 years (with an overall price tag of $100 billion by all member nations), thus it is natural to ask about the ISS’s Return on Investment to justify its continuous operation and existence its scientific payoff. While this is not a trivial financial question, a more appropriate measure for the ISS would be the Return on Innovation phrased from the perspective of: “What is the cost of NOT innovating and NOT exploring in microgravity?” This simply correlates with the otherwise-not-accessible-knowledge, the number of unique “lessons learned” and discoveries, especially those that enable humanity to pursue solutions for global critical problems and open up new avenues in areas at big impasse. To add to it, maybe space is the necessary step that humanity will have to undertake to progress, to change consciousness and awareness and to encourage creative cooperation coupled with a communitarian view of Earths future.
ISS is a top engineering achievement in space harboring a myriad of outstanding fundamental scientific investigations. There is a growing interest in highlighting the ISS achievements especially from the perspective of their impact on terrestrial technologies and by being the source of a cascade of accomplishments and developments ranging from the seed scientific discoveries to direct applications, many of them serendipitous in nature. The ultimate goal is to build upon these successes to increase the potential of commercialization and to create a stable, self-sustainable space based market. An overview of already identified microgravity benefits to material and life sciences will be given as well as examples highlighting the breadth of these scientific investigations and the aforementioned serendipitous effects. The value of a space-based novel initiatives will be explored with specific examples in the works.
The talk will also touch upon the need for a customized on-demand payload return from the ISS to augment the current payload downmass to Earth and increase the ISS commercialization potential. The existing transportation infrastructure is correlated with the current ISS utilization demands in terms of bulk downmass and schedule frequency and it is operated by the SpaceX Dragon Capsule and the Russian Soyuz with a combined frequency of about three to seven times per year. Based on previous experience with commercial partners it appears that a customized on-demand payload return system better meets the customers' needs and directly encourages potential emerging markets of ISS users. The talk will briefly step through the rationale behind defining a metric (requirements and design functions) that identifies/assigns quantifiable system level parameters to capture the various aspects of the need for a customized on-demand payload return from the ISS.
ISS is the first platform of its kind that enabled long term human presence in space, long term exploration of skills needed to survive the extreme environment, long terms exposure of basic scientific experiments to the microgravity environment. No matter what angle we look at it, the ISS is first and foremost a learning platform. As such its primary role is to help answer fundamental questions about living and working in space and help figure out the capabilities we need that we don’t have to ensure a future sustainable human exploration: one facet oriented towards the depths of space, the other towards Earth.
Abstract: With its subsurface water ocean and relatively young icy surface Europa is among the top candidates in the search for habitable environments in our solar system. Existence of water vapor plumes on Europa has long been speculated and could possibly provide accessibility of subsurface liquid reservoirs.
Images of auroral emissions obtained in December 2012 by the Hubble Space Telescope (HST) revealed coincident signals from hydrogen and oxygen pointing to the existence of transient water vapor near the moon’s south pole. The aurora is excited by impinging charged particles from Jupiter’s huge magnetosphere, which interacts with Europa’s atmosphere and interior water ocean.
Dr. Roth will provide an overview of the complex interaction between Europa and Jupiter’s magnetosphere, the generation of the plume aurora signals and our HST detection method, and the important implications of the plume discovery for the future exploration of Europa and its hidden water ocean.
Abstract: Sona Hosseini will report on progress toward development of a tunable spatial heterodyne spectrometer (TSHS) at the fixed focus of the Coudé Auxiliary Telescope (CAT) in the Shane Telescope at Lick Observatory (Khayyam). Spatial Heterodyne Spectrometer (SHS) instruments are a class of interferometric sensor capable of providing a combination of large étendue, high resolving power (R=λ/dλ~ 105) and wide field of view (FOV~0.5 degree) at Optical and NUV wavelengths in a compact format.
The TSHS implementation addresses the bandpass limitation of the basic SHS through controlled rotation of pilot mirrors in the interferometer. The use of a single grating as both a dispersing and beam-splitting element in the all reflective SHS greatly relaxes the precision required in the alignment of the other optical elements relative to a more typical scanning Fourier Transform Spectrometer and allows the TSHS implementation to be accomplished with low cost commercial rotation stages. The new design builds on a previous design originally tested in 2007, and will address several issues identified with the input beam, output imaging, and grating efficiency. Here she will discuss the design considerations going into this new system and the initial results of the installation and testing of the TSHS and the future plans.
Following completion of the ground based TSHS version (Khayyam), the longer term goals of the TSHS project are to provide in flight testing on a sounding rocket platform that Sona’s research group is developing and then ultimately a translation to satellite applications.