Biosignatures Search in Habitable Planets
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Lurking in the Shadows: Wide-Separation Gas Giants As Tracers of Planet Formation
Lurking in the Shadows: Wide-Separation Gas Giants as Tracers of Planet Formation Thesis by Marta Levesque Bryan In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy CALIFORNIA INSTITUTE OF TECHNOLOGY Pasadena, California 2018 Defended May 1, 2018 ii © 2018 Marta Levesque Bryan ORCID: [0000-0002-6076-5967] All rights reserved iii ACKNOWLEDGEMENTS First and foremost I would like to thank Heather Knutson, who I had the great privilege of working with as my thesis advisor. Her encouragement, guidance, and perspective helped me navigate many a challenging problem, and my conversations with her were a consistent source of positivity and learning throughout my time at Caltech. I leave graduate school a better scientist and person for having her as a role model. Heather fostered a wonderfully positive and supportive environment for her students, giving us the space to explore and grow - I could not have asked for a better advisor or research experience. I would also like to thank Konstantin Batygin for enthusiastic and illuminating discussions that always left me more excited to explore the result at hand. Thank you as well to Dimitri Mawet for providing both expertise and contagious optimism for some of my latest direct imaging endeavors. Thank you to the rest of my thesis committee, namely Geoff Blake, Evan Kirby, and Chuck Steidel for their support, helpful conversations, and insightful questions. I am grateful to have had the opportunity to collaborate with Brendan Bowler. His talk at Caltech my second year of graduate school introduced me to an unexpected population of massive wide-separation planetary-mass companions, and lead to a long-running collaboration from which several of my thesis projects were born. -
Lecture-29 (PDF)
Life in the Universe Orin Harris and Greg Anderson Department of Physics & Astronomy Northeastern Illinois University Spring 2021 c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 1 / 95 Overview Dating Rocks Life on Earth How Did Life Arise? Life in the Solar System Life Around Other Stars Interstellar Travel SETI Review c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 2 / 95 Dating Rocks Zircon Dating Sedimentary Grand Canyon Life on Earth How Did Life Arise? Life in the Solar System Life Around Dating Rocks Other Stars Interstellar Travel SETI Review c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 3 / 95 Zircon Dating Zircon, (ZrSiO4), minerals incorporate trace amounts of uranium but reject lead. Naturally occuring uranium: • U-238: 99.27% • U-235: 0.72% Decay chains: • 238U −→ 206Pb, τ =4.47 Gyrs. • 235U −→ 207Pb, τ = 704 Myrs. 1956, Clair Camron Patterson dated the Canyon Diablo meteorite: τ =4.55 Gyrs. c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 4 / 95 Dating Sedimentary Rocks • Relative ages: Deeper layers were deposited earlier • Absolute ages: Decay of radioactive isotopes old (deposited last) oldest (depositedolder first) c 2012-2021 G. Anderson., O. Harris Universe: Past, Present & Future – slide 5 / 95 Grand Canyon: Earth History from 200 million - 2 billion yrs ago. Dating Rocks Life on Earth Earth History Timeline Late Heavy Bombardment Hadean Shark Bay Stromatolites Cyanobacteria Q: Earliest Fossils? Life on Earth O2 History Q: Life on Earth How Did Life Arise? Life in the Solar System Life Around Other Stars Interstellar Travel SETI Review c 2012-2021 G. -
BRAS Newsletter August 2013
www.brastro.org August 2013 Next meeting Aug 12th 7:00PM at the HRPO Dark Site Observing Dates: Primary on Aug. 3rd, Secondary on Aug. 10th Photo credit: Saturn taken on 20” OGS + Orion Starshoot - Ben Toman 1 What's in this issue: PRESIDENT'S MESSAGE....................................................................................................................3 NOTES FROM THE VICE PRESIDENT ............................................................................................4 MESSAGE FROM THE HRPO …....................................................................................................5 MONTHLY OBSERVING NOTES ....................................................................................................6 OUTREACH CHAIRPERSON’S NOTES .........................................................................................13 MEMBERSHIP APPLICATION .......................................................................................................14 2 PRESIDENT'S MESSAGE Hi Everyone, I hope you’ve been having a great Summer so far and had luck beating the heat as much as possible. The weather sure hasn’t been cooperative for observing, though! First I have a pretty cool announcement. Thanks to the efforts of club member Walt Cooney, there are 5 newly named asteroids in the sky. (53256) Sinitiere - Named for former BRAS Treasurer Bob Sinitiere (74439) Brenden - Named for founding member Craig Brenden (85878) Guzik - Named for LSU professor T. Greg Guzik (101722) Pursell - Named for founding member Wally Pursell -
Lennon Reunion, Page 6 “There Will Be a Huge Transformation of the Page 2 July 4, 2013 TORRANCE TRIBUNE Calendar People FRIDAY, JULY 5 Torrance Blvd
The Weekly Newspaper of Torrance Herald Publications - Torrance, El Segundo, Manhattan Beach, Hawthorne, Lawndale, & Inglewood Community Newspapers Since 1911 - (310) 322-1830 - Vol. 3, No. 26 - July 4, 2013 Torrance Salutes Independence Inside Day Sans Fireworks Show This Issue Business & Professional ......................10 Calendar...............................2 Classifieds ...........................9 Crossword/Sudoku ............9 Police Reports ....................3 Politically Speaking ...........4 Real Estate. .......................12 The fourth of July, the most American of holidays, was again marked without parades or city-sponsored fireworks due to budget cuts but it did not stop residents from celebrating. Seen here is a skydiver with the American flag at the Torrance Centennial Celebration. Photo by TerriAnn Ferren. Sports ...................................5 City Council Previews Del Amo TerriAnn in Torrance .........6 Fashion Center Renovations By Dylan Little mall. The mall will not look anywhere near and going to other places in Southern California On Tuesday, the Torrance City Council heard how it looks today,” said Scotto. “When 2015 to shop, they’re going to stop in Torrance at a presentation from Simon Property Group on comes around, I think people will be extremely our Del Amo Mall. Come Thanksgiving this planned upgrades to the Del Amo Fashion pleased with the results we’re going to have year, we’ll get the first taste of that with the Center. Chuck Davis with Simon Property Group with this mall. Instead of driving by our mall See City Council, page 2 made a PowerPoint presentation that showed a nearly unrecognizable mall. One of the major Weekend changes was to divide the mall into the “Fashion Center” (focusing on clothes and high-end retail) TerriAnn: A Lennon and “Market Square” (focusing on home goods Forecast and furniture). -
Materials Challenges for the Starshot Lightsail
PERSPECTIVE https://doi.org/10.1038/s41563-018-0075-8 Materials challenges for the Starshot lightsail Harry A. Atwater 1*, Artur R. Davoyan1, Ognjen Ilic1, Deep Jariwala1, Michelle C. Sherrott 1, Cora M. Went2, William S. Whitney2 and Joeson Wong 1 The Starshot Breakthrough Initiative established in 2016 sets an audacious goal of sending a spacecraft beyond our Solar System to a neighbouring star within the next half-century. Its vision for an ultralight spacecraft that can be accelerated by laser radiation pressure from an Earth-based source to ~20% of the speed of light demands the use of materials with extreme properties. Here we examine stringent criteria for the lightsail design and discuss fundamental materials challenges. We pre- dict that major research advances in photonic design and materials science will enable us to define the pathways needed to realize laser-driven lightsails. he Starshot Breakthrough Initiative has challenged a broad nanocraft, we reveal a balance between the high reflectivity of the and interdisciplinary community of scientists and engineers sail, required for efficient photon momentum transfer; large band- Tto design an ultralight spacecraft or ‘nanocraft’ that can reach width, accounting for the Doppler shift; and the low mass necessary Proxima Centauri b — an exoplanet within the habitable zone of for the spacecraft to accelerate to near-relativistic speeds. We show Proxima Centauri and 4.2 light years away from Earth — in approxi- that nanophotonic structures may be well-suited to meeting such mately -
Water, Habitability, and Detectability Steve Desch
Water, Habitability, and Detectability Steve Desch PI, “Exoplanetary Ecosystems” NExSS team School of Earth and Space Exploration, Arizona State University with Ariel Anbar, Tessa Fisher, Steven Glaser, Hilairy Hartnett, Stephen Kane, Susanne Neuer, Cayman Unterborn, Sara Walker, Misha Zolotov Astrobiology Science Strategy NAS Committee, Beckmann Center, Irvine, CA (remotely), January 17, 2018 How to look for life on (Earth-like) exoplanets: find oxygen in their atmospheres How Earth-like must an exoplanet be for this to work? Seager et al. (2013) How to look for life on (Earth-like) exoplanets: find oxygen in their atmospheres Oxygen on Earth overwhelmingly produced by photosynthesizing life, which taps Sun’s energy and yields large disequilibrium signature. Caveats: Earth had life for billions of years without O2 in its atmosphere. First photosynthesis to evolve on Earth was anoxygenic. Many ‘false positives’ recognized because O2 has abiotic sources, esp. photolysis (Luger & Barnes 2014; Harman et al. 2015; Meadows 2017). These caveats seem like exceptions to the ‘rule’ that ‘oxygen = life’. How non-Earth-like can an exoplanet be (especially with respect to water content) before oxygen is no longer a biosignature? Part 1: How much water can terrestrial planets form with? Part 2: Are Aqua Planets or Water Worlds habitable? Can we detect life on them? Part 3: How should we look for life on exoplanets? Part 1: How much water can terrestrial planets form with? Theory says: up to hundreds of oceans’ worth of water Trappist-1 system suggests hundreds of oceans, especially around M stars Many (most?) planets may be Aqua Planets or Water Worlds How much water can terrestrial planets form with? Earth- “snow line” Standard Sun distance models of distance accretion suggest abundant water. -
Polarimetry in Bistatic Configuration for Ultra High Frequency Radar Measurements on Forest Environment Etienne Everaere
Polarimetry in Bistatic Configuration for Ultra High Frequency Radar Measurements on Forest Environment Etienne Everaere To cite this version: Etienne Everaere. Polarimetry in Bistatic Configuration for Ultra High Frequency Radar Measure- ments on Forest Environment. Optics [physics.optics]. Ecole Polytechnique, 2015. English. tel- 01199522 HAL Id: tel-01199522 https://hal.archives-ouvertes.fr/tel-01199522 Submitted on 15 Sep 2015 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. École Doctorale de l’École Polytechnie Thèse présentée pour obtenir le grade de docteur de l’École Polytechnique spécialité physique par Étienne Everaere Polarimetry in Bistatic Conguration for Ultra High Frequency Radar Measurements on Forest Environment Directeur de thèse : Antonello De Martino Soutenue le 6 mai 2015 devant le jury composé de : Rapporteurs : François Goudail - Professeur à l’Institut d’optique Graduate School Fabio Rocca - Professeur à L’École Polytechnique de Milan Examinateurs : Élise Colin-K÷niguer - Ingénieur de recherche à l’ONERA Carole Nahum - Responsable -
Breakthrough Propulsion Study Assessing Interstellar Flight Challenges and Prospects
Breakthrough Propulsion Study Assessing Interstellar Flight Challenges and Prospects NASA Grant No. NNX17AE81G First Year Report Prepared by: Marc G. Millis, Jeff Greason, Rhonda Stevenson Tau Zero Foundation Business Office: 1053 East Third Avenue Broomfield, CO 80020 Prepared for: NASA Headquarters, Space Technology Mission Directorate (STMD) and NASA Innovative Advanced Concepts (NIAC) Washington, DC 20546 June 2018 Millis 2018 Grant NNX17AE81G_for_CR.docx pg 1 of 69 ABSTRACT Progress toward developing an evaluation process for interstellar propulsion and power options is described. The goal is to contrast the challenges, mission choices, and emerging prospects for propulsion and power, to identify which prospects might be more advantageous and under what circumstances, and to identify which technology details might have greater impacts. Unlike prior studies, the infrastructure expenses and prospects for breakthrough advances are included. This first year's focus is on determining the key questions to enable the analysis. Accordingly, a work breakdown structure to organize the information and associated list of variables is offered. A flow diagram of the basic analysis is presented, as well as more detailed methods to convert the performance measures of disparate propulsion methods into common measures of energy, mass, time, and power. Other methods for equitable comparisons include evaluating the prospects under the same assumptions of payload, mission trajectory, and available energy. Missions are divided into three eras of readiness (precursors, era of infrastructure, and era of breakthroughs) as a first step before proceeding to include comparisons of technology advancement rates. Final evaluation "figures of merit" are offered. Preliminary lists of mission architectures and propulsion prospects are provided. -
The Detectability and Constraints of Biosignature Gasses in the Near & Mid-Infrared from Transit Transmission Spectroscopy B
The Detectability and Constraints of Biosignature Gasses in the Near & Mid-Infrared from Transit Transmission Spectroscopy by Luke Tremblay A Thesis Presented in Partial Fulfillment of the Requirements for the Degree Master of Science Approved November 2019 by the Graduate Supervisory Committee: Michael Line, Chair Evgenya Schkolnik Sara Walker ARIZONA STATE UNIVERSITY December 2019 ABSTRACT The James Webb Space Telescope (JWST ) is expected to revolutionize the cur- rent understanding of Jovian worlds over the coming decade. However, as the field pushes towards characterizing cooler, smaller, \terrestrial-like" planets, dedicated next-generation facilities will be required to tease out the small spectral signatures indicative of biological activity. Here, the feasibility of determining atmospheric prop- erties, from near to mid-infrared transmission spectra, of transiting temperate ter- restrial M-dwarf companions, has been evaluated. Specifically, atmospheric retrievals were utilized to explore the trade space between spectral resolution, wavelength cover- age, and signal-to-noise on the ability to both detect molecular species and constrain their abundances. Increasing spectral resolution beyond R=100 for near-infrared wavelengths, shorter than 5µm, proves to reduce the degeneracy between spectral features of different molecules and thus greatly benefits the abundance constraints. However, this benefit is greatly diminished beyond 5µm as any overlap between broad features in the mid-infrared does not deconvolve with higher resolutions. Additionally, the inclusion of features beyond 11µm did not meaningfully improve the detection sig- nificance nor abundance constraints results. The findings of this study indicate that an instrument with continuous wavelength coverage from approximately 2-11µm and with a resolution of R'50-300, would be capable of detecting H2O, CO2, CH4,O3, and N2O in the atmosphere of an Earth-analog transiting an M-dwarf (magK =8.0) within 50 transits, and obtain better than an order-of-magnitude constraint on each of their abundances. -
Naming the Extrasolar Planets
Naming the extrasolar planets W. Lyra Max Planck Institute for Astronomy, K¨onigstuhl 17, 69177, Heidelberg, Germany [email protected] Abstract and OGLE-TR-182 b, which does not help educators convey the message that these planets are quite similar to Jupiter. Extrasolar planets are not named and are referred to only In stark contrast, the sentence“planet Apollo is a gas giant by their assigned scientific designation. The reason given like Jupiter” is heavily - yet invisibly - coated with Coper- by the IAU to not name the planets is that it is consid- nicanism. ered impractical as planets are expected to be common. I One reason given by the IAU for not considering naming advance some reasons as to why this logic is flawed, and sug- the extrasolar planets is that it is a task deemed impractical. gest names for the 403 extrasolar planet candidates known One source is quoted as having said “if planets are found to as of Oct 2009. The names follow a scheme of association occur very frequently in the Universe, a system of individual with the constellation that the host star pertains to, and names for planets might well rapidly be found equally im- therefore are mostly drawn from Roman-Greek mythology. practicable as it is for stars, as planet discoveries progress.” Other mythologies may also be used given that a suitable 1. This leads to a second argument. It is indeed impractical association is established. to name all stars. But some stars are named nonetheless. In fact, all other classes of astronomical bodies are named. -
Can There Be Additional Rocky Planets in the Habitable Zone of Tight Binary
Mon. Not. R. Astron. Soc. 000, 1–10 () Printed 24 September 2018 (MN LATEX style file v2.2) Can there be additional rocky planets in the Habitable Zone of tight binary stars with a known gas giant? B. Funk1⋆, E. Pilat-Lohinger1 and S. Eggl2 1Institute for Astronomy, University of Vienna, Vienna, Austria 2IMCCE, Observatoire de Paris, Paris, France ABSTRACT Locating planets in Habitable Zones (HZs) around other stars is a growing field in contem- porary astronomy. Since a large percentage of all G-M stars in the solar neighborhood are expected to be part of binary or multiple stellar systems, investigations of whether habitable planets are likely to be discovered in such environments are of prime interest to the scientific community. As current exoplanet statistics predicts that the chances are higher to find new worlds in systems that are already known to have planets, we examine four known extrasolar planetary systems in tight binaries in order to determine their capacity to host additional hab- itable terrestrial planets. Those systems are Gliese 86, γ Cephei, HD 41004 and HD 196885. In the case of γ Cephei, our results suggest that only the M dwarf companion could host ad- ditional potentially habitable worlds. Neither could we identify stable, potentially habitable regions around HD 196885A. HD 196885 B can be considered a slightly more promising tar- get in the search forEarth-twins.Gliese 86 A turned out to be a very good candidate, assuming that the system’s history has not been excessively violent. For HD 41004 we have identified admissible stable orbits for habitable planets, but those strongly depend on the parameters of the system. -
Gemini Planet Imager Spectroscopy of the Dusty Substellar Companion HD 206893 B
The Astronomical Journal, 161:5 (24pp), 2021 January https://doi.org/10.3847/1538-3881/abc263 © 2020. The American Astronomical Society. All rights reserved. Gemini Planet Imager Spectroscopy of the Dusty Substellar Companion HD206893B K. Ward-Duong1,2 , J. Patience2, K. Follette3 , R. J. De Rosa4,5 , J. Rameau6,7 , M. Marley8 , D. Saumon9 , E. L. Nielsen4 , A. Rajan10 , A. Z. Greenbaum11 , J. Lee12, J. J. Wang13,14,40 , I. Czekala4,14,41 , G. Duchêne6,14 , B. Macintosh4 , S. Mark Ammons15 , V. P. Bailey16 , T. Barman17 , J. Bulger18,19 , C. Chen10 , J. Chilcote4,20 , T. Cotten12 , R. Doyon7, T. M. Esposito14 , M. P. Fitzgerald21 , B. L. Gerard22,23 , S. J. Goodsell24 , J. R. Graham14, P. Hibon5 , J. Hom2 , L.-W. Hung25 , P. Ingraham26 , P. Kalas14,27 , Q. Konopacky28 , J. E. Larkin21 , J. Maire28, F. Marchis27 , C. Marois23,29 , S. Metchev30,31 , M. A. Millar-Blanchaer16,42 , R. Oppenheimer32 , D. Palmer15 , M. Perrin10 , L. Poyneer15, L. Pueyo10, F. T. Rantakyrö33 , B. Ren34 , J.-B. Ruffio4 , D. Savransky35 , A. C. Schneider36,37 , A. Sivaramakrishnan10 , I. Song12 , R. Soummer10 , M. Tallis4, S. Thomas26 , J. Kent Wallace16 , S. Wiktorowicz38 , and S. Wolff39 1 Five College Astronomy Department, Amherst College, Amherst, MA 01002, USA; [email protected] 2 School of Earth and Space Exploration, Arizona State University, P.O. Box 871404, Tempe, AZ 85287, USA 3 Physics & Astronomy Department, Amherst College, 21 Merrill Science Drive, Amherst, MA 01002, USA 4 Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA 5 European Southern Observatory, Alonso de Córdova 3107, Vitacura, Santiago, Chile 6 Univ.