Space Telescope Science Institute Webcast Series Seminars Hopkins University and the Space Telescope Science Institute present live and on-demand webcasts related to science, technology, and business to the scientific community and the public at-large. Live webcasts, production services, and the webcast archive are managed by the Information Technology Services division of the Space Telescope Science Institute. Seminarsen-usSat, 06 Jun 2020 05:18:41 +0000Contemporary Water and Habitability of Mars is the only other planet besides Earth with multiple lines of geomorphic and spectral evidence for the past existence of flowing water on the surface. In the current climate, water on Mars exists almost entirely in the form of ice and in minor form as a gas. The notion of contemporary liquid water on Mars has been controversial. Pure liquid water on the surface would be rapidly lost to the tenuous atmosphere of Mars via evaporation; however, brines can be stable on the Martian surface for an extended period due to their lower eutectic temperature and evaporation rate. One of the major Mars discoveries of recent years is the existence of recurring slope lineae (RSL), which suggests that liquid water may occur on or near the surface of Mars today. Recently, hydrated oxychlorine salts, including perchlorates, were spectrally detected at sites hosting RSL which implicates that water does play a role in the formation of RSL, although the magnitude of the role is uncertain. If RSL are indeed contemporary brines on Mars, they might provide transiently wet conditions near the surface on Mars, although the water activity in oxychlorine-salt solutions may be too low to support known terrestrial life. Widespread perchlorates may also challenge our ability to characterize some organic species via traditional pyrolysis experiments on Mars because of their reactivity with organics. Further astrobiological characterization and exploration of these unique regions on Mars are necessary to fully assess the current habitability of Mars. and the Antropocene Epoch by comparative planetology and a survey of the major episodes in Earth history, this lecture will offer taxonomy of planetary catastrophes meant to illuminate the unusual nature of the “Anthropocene”, the current era 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 attempting to create a wisely managed Earth., Life, and the Universe Lecture Series (2009 - Present) Planets, Life, and the Universe lecture series brings high-profile speakers to the JHU/STScI campus to discuss current topics of interest in astrobiology. All lectures are presented live online and are available for <a href="" target="_blank">viewing on the website .</a> Falls: Portal Into an Antarctic Subglacial Microbial World Falls is an iron-rich, saline feature at the terminus of Taylor Glacier in the McMurdo Dry Valleys, Antarctica. Geophysical and geochemical data indicate that the source of this surface outflow originates below the glacier, however the extent of the subglacial brine remains unknown. The brine harbors a microbial community that persists, despite cold, dark isolation. In order to better understand this ecosystem, drilling into the subglacial source will be required. Antarctic subglacial environments, like astrobiological targets on extraterrestrial worlds, are pristine ecosystems that warrant protection. Modern ice drilling projects, such as those planned for Blood Falls, are developing clean access approaches to prevent the contamination of both the subglacial environment and the samples retrieved. In this talk I will highlight recent expeditions to Blood Falls, which collectively shape our current understanding of the Taylor Glacier ecosystem. The brine below Taylor Glacier is an example of the diversity of potential microbial habitats hidden beneath Antarctic ice and provides important insight into subice microbial community structure and function. Collaborative, interdisciplinary studies of Blood Falls, such as those presented here, will enable the development of relevant tools for geomicrobiological examination of other subglacial environments on Earth and help prepare us for the exploration of icy extraterrestrial targets. Ingredients for Life's Cassini mission has revealed Saturn's larger moon Titan to be a world rich in the "stuff of life." Reactions occurring in its dense nitrogen-methane atmosphere produce a wide variety of organic molecules, which subsequently rain down onto its surface. If these molecules mix with water found in cryovolanic lavas or impact melts on Titan's surface, they may react to form biological molecules such as amino acids. In this presentation, I will report on experimental work seeking to determine the type and quantity of biomolecules formed under conditions analogous to those found in transient liquid water environments on Titan. These reactions are intriguingly similar to reactions that may have occurred on the early Earth, and provide clues to the origin of life on our own world and worlds throughout the universe. and Temperatures of Exoplanet Atmospheres With HST/WFC3 Wide Field Camera 3 (WFC3) on HST provides the opportunity for spectroscopic characterization of molecular features in transiting exoplanet atmospheres, a capability that has not existed in space since the demise of NICMOS on HST and the IRS on Spitzer. WFC3's slitless grism design and the stable and reliable pointing and thermal environment of HST provide an excellent platform for high-precision spectroscopic monitoring of transiting exoplanet host stars. Additionally, the wavelength range of WFC3's long-wavelength grism covers several molecular absorption bands which are relevant to planetary atmospheres, most notably the 1.4 micron water band. I will present analysis of WFC3 transit and eclipse measurements for a number of highly irradiated, Jupiter-mass planets observed over several HST cycles, with a focus on confirming which planets exhibit water absorption in transit and/or eclipse and measuring the characteristic brightness temperature at these wavelengths. Measurements of molecular absorption in the atmospheres of these planets offer the chance to explore several outstanding questions regarding the atmospheric structure and composition of hot Jupiters, including the possibility of bulk compositional variations between planets and the presence or absence of a stratospheric temperature inversion, and I will describe our progress and plans towards resolving some of these questions. Origins: Snowlines During Star and Planet Formation the cold and dense stages of star and planet formation, volatile molecules condense out on interstellar grains forming icy mantles. This condensation process results in a series of snowlines, or condensation fronts, whose exact locations are set by a combination of thermal and non-thermal adsorption and desorption processes. The icy grain mantles are also active chemical sites, resulting in a changing ice composition with time, typically to include an increasing fraction of complex organic molecules. The nature of these snowlines in protoplanetary disks are predicted to have large impacts on planet formation efficiencies, on the bulk compositions of the forming planets, and on the amount of prebiotic material available on planet surfaces. We have used a combination of IR and millimeter observations, theory, and laboratory experiments to characterize interstellar ices, snow line locations (i.e. where these ices are located), and the chemical and planet formation consequences of the exact locations of different snow lines. I will discuss how the outcome of these studies have impacted our understanding of ice formation during star and planet formation, and also future prospects as complete ALMA and the next generation of laboratory experiments come online. of Exoplanetary Atmospheres and Interiors advances in exoplanet observations and theoretical methods are leading to unprecedented constraints on the physicochemical properties of exoplanetary atmospheres, interiors, and their formation conditions. In this talk, I will present some of the latest results in this emerging frontier. I will present constraints on the atmospheric chemical compositions and temperature profiles for a variety of exoplanets based on infrared observations from a wide range of facilities including HST, Spitzer, and ground-based telescopes. I will discuss how these constraints are being used to understand various equilibrium and non-equilibrium processes in exoplanetary atmospheres, to develop new classification schemes for exoplanets, and to understand the conditions of their formation and subsequent evolution. I will also present the latest constraints emerging on the atmospheres, interior structures, and formation environments of super-Earths, whose interior compositions span a wide gamut - from water worlds with thick volatile envelopes to super-Mercuries, lava planets, and carbon planets - thereby testing the limits of our understanding of planetary mineralogies and their equations of state under exotic astrophysical conditions. The exciting future prospects of characterizing exoplanetary atmospheres, interiors, and formation conditions, using current, upcoming, and future observational facilities will be discussed, along with several open questions of fundamental nature in the field. Zones and the Frequency of Potential Habitable Planets in Extrasolar Planetary Systems terrestrial planets in the habitable zones (HZs) of other stars is one of the primary goals of ongoing exoplanet surveys and proposed space-based flagship missions. In this talk, I will discuss about our recent results on new estimates of HZs around Main-sequence stars. According to our new model, the inner and outer HZ limits for our Solar System are at 0.99 AU and 1.67 AU, respectively, suggesting that the present Earth lies near the inner edge. Our model does not include the radiative effects of clouds; thus, the actual HZ boundaries may be broader than our estimates. Applying the new HZ limits to cool, low mass stars (M-dwarfs) in NASA's "Kepler" data, we find that potentially habitable planets around M-dwarfs are more common than previously reported. The mean distance to the nearest habitable planet may be as close as 7 light years from us. Your Curiosity: The Search for Habitable Environments on Mars this talk, Glavin will describe the concept of a ?habitable environment? and the requirements for life as we know it. Understanding the basic requirements for life and the prebiotic chemistry that led to the emergence of life on Earth will help guide our search for life on Mars. Glavin will also give an overview of NASA's Mars Science Laboratory mission with an update on the progress of the Curiosity rover and a summary of the analytical capabilities and measurement objectives of the SAM experiment. Curiosity is currently getting ready for the first SAM analysis of a drilled rock on Mars and will take a step closer to answering the question of whether Mars could have ever supported life.