DOCSLIB.ORG

Atmospheric Escape from TOI-700 D

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Atmospheric Escape from TOI-700 D U.S. DEPARTMENT OF ENERGY U.S. DEPARTMENT OF U.S. DEPARTMENT OF ENERGYENERGY U.S. DEPARTMENT OF U.S. DEPARTMENT OF ENERGY ENERGY U.S. DEPARTMENT OF U.S. DEPARTMENT OF ENERGYENERGY U.S. DEPARTMENT OF Atmospheric EscapeENERGY From TOI-700 d: Venus versus Earth Analogs Chuanfei Dong1,2, Meng Jin3,4, Manasvi Lingam5,6 1 Department of Astrophysical Sciences, Princeton University; [email protected] 2 Princeton Plasma Physics Laboratory, Princeton University, [email protected] 3 SETI Institute 4 Lockheed Martin Solar and Astrophysics Lab (LMSAL) 5 Department of Aerospace, Physics and Space Sciences, Florida Tech 6 Institute for Theory and Computation, Harvard University 18th Meeting of the Venus Exploration Analysis Group (VEXAG) Habitable Zone of TOI-700 Green Band: Habitable Zone semimajor axis = 0.163±0.015 AU The first Earth-size planet in its star’s habitable zone discovered by TESS. What will happen when considering the stellar wind and magnetic field? Unmagnetized Venus Magnetized Earth 3 How Does the Sun/Star Affect the Planetary System? Solar Wind Earth-like Magnetized Venus/Mars-like Unmagnetized Exosphere Ionospheric Density Profiles of Venus and Earth Venus Earth Density Peak (O2+) at ~135 km Density Peak (O+)at ~300 km 5 Mendillo et al., 2018 Atmospheric O+ Ion Source and Loss Phi -3 -1 Phi -3 -1 + -3 + -3 RO+ in cm s (early) RO+ in cm s (Carrington) 4 4 4 n(O ) in cm (early) n(O ) in cm (Carrington) 3 3 4 3 Photoionization 2 2 4 4 Z 2 1 1 3 0 0 1 2 2 -1 -1 0 -2 -2 Z 2 -2 Imp-1 0-3 -1 1 2 -2Imp -1 -3 0-1 1 2 RO+ in cm s (early) RO+ in cm s (Carrington) 4 X 4 X 4 0 0 Electron 3Impact Ionization 3 3 1 2 2 -2 -2 Z 2 1 1 0 0 0 1 -2 -1 0 1 2 -2 -1 0 1 2 -1 -1 0 -2 -2 X X -2 CX-1 0-3 -1 1 2 -2CX -1 -3 0-1 1 2 RO+ in cm s (early) RO+ in cm s (Carrington) 4 X 4 X 4 Ancient (4.02 Gyr) solar wind An extreme “Carrington-type” 3 Charge Exchange 3 parameters at 1 au (stellar input space weather event (stellar 3 2 2 from Boesswetter et al. 2010). input from Ngwira et al. 2014) Z 2 1 1 0 0 1 -1 -1 Joule heating included: 0 -2 -2 -2 -1 0 1 2 -2 -1 0 1 2 X X Dong et al., 2017, ApJL; Dong et al., 2019, ApJL Stellar Wind Velocity Stellar Wind Pressure Stellar Wind Density 7 Atmospheric Escape From TOI-700 d (at Pmin): Venus versus Earth Analogs Assuming exoplanets with Venus-like and Earth-like atmospheres orbiting M-type stars instead of solar-type stars. Given the close-in habitable zones of M-type stars, those exoplanets experience higher radiation and particle fluxes than our Venus and Earth. Unmagnetized Venus Unmagnetized Earth Magnetized Earth 2.10×1026 S-1 1.18×1028 S-1 1.39×1027 S-1 8 Dong et al., 2020, ApJL Conclusion • We assess the feasibility of TOI-700 d to retain an atmosphere – one of the chief ingredients for surface habitability – over long timescales by employing state-of-the-art magnetohydrodynamic models to simulate the stellar wind and the associated rates of atmospheric escape. • The simulations show that the unmagnetized TOI-700 d with a 1 bar Earth-like atmosphere could be stripped away rather quickly (< 1 gigayear), while the unmagnetized TOI-700 d with a 1 bar CO2-dominated atmosphere could persist for many billions of years; we find that the magnetized Earth-like case falls in between these two scenarios. • Space weather and stellar wind-induced atmospheric loss need to be taken into account for planetary habitability! Thank You for Your Attention! Traditional Habitable Zones Dong et al., 2018, PNAS Green Band: Habitable Zone.
Load more

Recommended publications
  • A Review of Possible Planetary Atmospheres in the TRAPPIST-1 System
    Space Sci Rev (2020) 216:100 https://doi.org/10.1007/s11214-020-00719-1 A Review of Possible Planetary Atmospheres in the TRAPPIST-1 System Martin Turbet1 · Emeline Bolmont1 · Vincent Bourrier1 · Brice-Olivier Demory2 · Jérémy Leconte3 · James Owen4 · Eric T. Wolf5 Received: 14 January 2020 / Accepted: 4 July 2020 / Published online: 23 July 2020 © The Author(s) 2020 Abstract TRAPPIST-1 is a fantastic nearby (∼39.14 light years) planetary system made of at least seven transiting terrestrial-size, terrestrial-mass planets all receiving a moderate amount of irradiation. To date, this is the most observationally favourable system of po- tentially habitable planets known to exist. Since the announcement of the discovery of the TRAPPIST-1 planetary system in 2016, a growing number of techniques and approaches have been used and proposed to characterize its true nature. Here we have compiled a state- of-the-art overview of all the observational and theoretical constraints that have been ob- tained so far using these techniques and approaches. The goal is to get a better understanding of whether or not TRAPPIST-1 planets can have atmospheres, and if so, what they are made of. For this, we surveyed the literature on TRAPPIST-1 about topics as broad as irradiation environment, planet formation and migration, orbital stability, effects of tides and Transit Timing Variations, transit observations, stellar contamination, density measurements, and numerical climate and escape models. Each of these topics adds a brick to our understand- ing of the likely—or on the contrary unlikely—atmospheres of the seven known planets of the system.
    [Show full text]
  • The Search for Another Earth – Part II
    GENERAL ARTICLE The Search for Another Earth – Part II Sujan Sengupta In the first part, we discussed the various methods for the detection of planets outside the solar system known as the exoplanets. In this part, we will describe various kinds of exoplanets. The habitable planets discovered so far and the present status of our search for a habitable planet similar to the Earth will also be discussed. Sujan Sengupta is an 1. Introduction astrophysicist at Indian Institute of Astrophysics, Bengaluru. He works on the The first confirmed exoplanet around a solar type of star, 51 Pe- detection, characterisation 1 gasi b was discovered in 1995 using the radial velocity method. and habitability of extra-solar Subsequently, a large number of exoplanets were discovered by planets and extra-solar this method, and a few were discovered using transit and gravi- moons. tational lensing methods. Ground-based telescopes were used for these discoveries and the search region was confined to about 300 light-years from the Earth. On December 27, 2006, the European Space Agency launched 1The movement of the star a space telescope called CoRoT (Convection, Rotation and plan- towards the observer due to etary Transits) and on March 6, 2009, NASA launched another the gravitational effect of the space telescope called Kepler2 to hunt for exoplanets. Conse- planet. See Sujan Sengupta, The Search for Another Earth, quently, the search extended to about 3000 light-years. Both Resonance, Vol.21, No.7, these telescopes used the transit method in order to detect exo- pp.641–652, 2016. planets. Although Kepler’s field of view was only 105 square de- grees along the Cygnus arm of the Milky Way Galaxy, it detected a whooping 2326 exoplanets out of a total 3493 discovered till 2Kepler Telescope has a pri- date.
    [Show full text]
  • The Subsurface Habitability of Small, Icy Exomoons J
    A&A 636, A50 (2020) Astronomy https://doi.org/10.1051/0004-6361/201937035 & © ESO 2020 Astrophysics The subsurface habitability of small, icy exomoons J. N. K. Y. Tjoa1,?, M. Mueller1,2,3, and F. F. S. van der Tak1,2 1 Kapteyn Astronomical Institute, University of Groningen, Landleven 12, 9747 AD Groningen, The Netherlands e-mail: [email protected] 2 SRON Netherlands Institute for Space Research, Landleven 12, 9747 AD Groningen, The Netherlands 3 Leiden Observatory, Leiden University, Niels Bohrweg 2, 2300 RA Leiden, The Netherlands Received 1 November 2019 / Accepted 8 March 2020 ABSTRACT Context. Assuming our Solar System as typical, exomoons may outnumber exoplanets. If their habitability fraction is similar, they would thus constitute the largest portion of habitable real estate in the Universe. Icy moons in our Solar System, such as Europa and Enceladus, have already been shown to possess liquid water, a prerequisite for life on Earth. Aims. We intend to investigate under what thermal and orbital circumstances small, icy moons may sustain subsurface oceans and thus be “subsurface habitable”. We pay specific attention to tidal heating, which may keep a moon liquid far beyond the conservative habitable zone. Methods. We made use of a phenomenological approach to tidal heating. We computed the orbit averaged flux from both stellar and planetary (both thermal and reflected stellar) illumination. We then calculated subsurface temperatures depending on illumination and thermal conduction to the surface through the ice shell and an insulating layer of regolith. We adopted a conduction only model, ignoring volcanism and ice shell convection as an outlet for internal heat.
    [Show full text]
  • The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI 700 D
    The Astrophysical Journal, 897:101 (11pp), 2020 July 1 https://doi.org/10.3847/1538-4357/ab9637 © 2020. The American Astronomical Society. All rights reserved. The Space Environment and Atmospheric Joule Heating of the Habitable Zone Exoplanet TOI 700 d Ofer Cohen1 , C. Garraffo2,3 ,Sofia-Paraskevi Moschou3 , Jeremy J. Drake3 , J. D. Alvarado-Gómez4 , Alex Glocer5, and Federico Fraschetti6 1 Lowell Center for Space Science and Technology, University of Massachusetts Lowell, 600 Suffolk Street, Lowell, MA 01854, USA; [email protected] 2 Institute for Applied Computational Science, Harvard University, 33 Oxford Street, Cambridge, MA, USA 3 Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, USA 4 Leibniz Institute for Astrophysics Potsdam, An der Sternwarte 16, D-14482 Potsdam, Germany 5 NASA Goddard Space Flight Center, Greenbelt, MD, USA 6 Dept. of Planetary Sciences-Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA Received 2020 February 22; revised 2020 May 5; accepted 2020 May 23; published 2020 July 7 Abstract We investigate the space environment conditions near the Earth-size planet TOI700d using a set of numerical models for the stellar corona and wind, the planetary magnetosphere, and the planetary ionosphere. We drive our simulations using a scaled-down stellar input and a scaled-up solar input in order to obtain two independent solutions. We find that for the particular parameters used in our study, the stellar wind conditions near the planet are not very extreme—slightly stronger than that near the Earth in terms of the stellar wind ram pressure and the intensity of the interplanetary magnetic field.
    [Show full text]
  • Open Engagment Group A
    Habitable Worlds 2021 Workshop Open Engagement – Group B Abstract Title 1st Author # 19 Obliquity Variation of Circumbinary Planets Gongjie Li Removing Stellar Activity Signals from Radial 34 Zoe de Beurs Velocity Measurements Using Neural Networks 40 Dayside land on tidally locked M-Earths Evelyn Macdonald Effect of mantle oxidation state on the magma ocean 87 Nisha Katyal atmospheric evolution Stellar Variability & Precision Radial Velocimetry: 89 Eric Ford Lessons for atmospheric characterization Is there any other habitable planets in universe 91 Md Redyan Ahmed except Earth? Stellar Energetic Particle-driven Production of Biologically Relevant Molecules in Atmospheres of 93 Guillaume Gronoff Young Earth-like Exoplanets Around Active G-K Stars 97 Stable, Closely-Spaced Three-Planet Systems Sacha Gavino Ground-Based Exoplanet Direct Imaging in the Next 98 Thayne Currie Decade: The Path to Imaging Another Earth Magma ocean differentiation regime in the earliest 101 Damanveer Grewal formed rocky bodies -Internal or External? A very early origin of isotopically distinct nitrogen 102 Damanveer Grewal in the inner Solar System protoplanets XUV-Driven Atmospheric Mass Loss of M Dwarf 103 Laura Amaral Planets due to Flaring Impact of Tides on the Potential for Exoplanets to 104 Armen Tokadjian Host Exomoons 105 Drifting into habitability Bradley Hansen 106 How to Detect a Dead Planet Sara Walker Computational study on the importance of UV light 107 in the production of molecules of prebiotic Marion Armas Vazquez importance in an astrobiological
    [Show full text]
  • Comparative Habitability of Transiting Exoplanets
    Draft version October 1, 2015 A Preprint typeset using LTEX style emulateapj v. 04/17/13 COMPARATIVE HABITABILITY OF TRANSITING EXOPLANETS Rory Barnes1,2,3, Victoria S. Meadows1,2, Nicole Evans1,2 Draft version October 1, 2015 ABSTRACT Exoplanet habitability is traditionally assessed by comparing a planet’s semi-major axis to the location of its host star’s “habitable zone,” the shell around a star for which Earth-like planets can possess liquid surface water. The Kepler space telescope has discovered numerous planet candidates near the habitable zone, and many more are expected from missions such as K2, TESS and PLATO. These candidates often require significant follow-up observations for validation, so prioritizing planets for habitability from transit data has become an important aspect of the search for life in the universe. We propose a method to compare transiting planets for their potential to support life based on transit data, stellar properties and previously reported limits on planetary emitted flux. For a planet in radiative equilibrium, the emitted flux increases with eccentricity, but decreases with albedo. As these parameters are often unconstrained, there is an “eccentricity-albedo degeneracy” for the habitability of transiting exoplanets. Our method mitigates this degeneracy, includes a penalty for large-radius planets, uses terrestrial mass-radius relationships, and, when available, constraints on eccentricity to compute a number we call the “habitability index for transiting exoplanets” that represents the relative probability that an exoplanet could support liquid surface water. We calculate it for Kepler Objects of Interest and find that planets that receive between 60–90% of the Earth’s incident radiation, assuming circular orbits, are most likely to be habitable.
    [Show full text]
  • Canopus XVII Básicamente La Escribió Él
    N° 17 ENE 2020 rreevviissttaa ccaannooppuuss LA REVISTA DE COMUNICACIÓN CIENTÍFICA EDITORIAL Empezamos un nuevo año, 2020, siempre que cambia ese número, el común de las personas siente una renovación, nuevos objetivos, nuevo “aire” como comúnmente se dice. Por nuestra parte, en este enero 2020 estamos mucho mejor parados que en enero del año pasado, de hecho hace un año no hubo publicaciones, comenzamos en febrero con el número V cuando asumí la dirección editorial de este medio digital. Vale destacar algo que no mencionamos en el número pasado, hubo cambio de gestión y organigrama. El Complejo Planetario Malargüe no es más una dirección, si no que es una coordinación. Dicha coordinación, de Marcelo Salvadores depende de la dirección de Industrias y Negocios municipales, a cargo de Marilé Verón. Subiendo un escalón más está la Secretaría Rural, Tecnología Ciencia e Innovación bajo el mando de nuestro ex compañero, César Ojeda, a quien felicitamos desde nuestro pequeño espacio conformado por Agustín y yo. Como hemos ido haciendo estos últimos meses, se ha incrementado la cantidad de contenido, lo que nos lleva a agregar más páginas, digitales por suerte a esta revista. Este número supera las 70 páginas y hablamos de temáticas muy variadas. Quiero agradecer a Agustín, ya que desde el 10 de diciembre soy Coordinador Científico del Planetario, y, por temas de temporada y arreglos, el estar ocupado en esos temas, no he podido dedicarme a la escritura. Canopus XVII básicamente la escribió él. Comenzamos el año con la noticia de que ¡Argentina tiene un planeta! No es tan literal, pero sí que pudimos nombrar a uno, el concurso fue desde la UAI y canalizado desde el Nodo Nacional Argentino para la difusión de la Astronomía, donde el Planetario fue parte.
    [Show full text]
  • PLANETARY CANDIDATES OBSERVED by Kepler. VIII. a FULLY AUTOMATED CATALOG with MEASURED COMPLETENESS and RELIABILITY BASED on DATA RELEASE 25
    Draft version October 13, 2017 Typeset using LATEX twocolumn style in AASTeX61 PLANETARY CANDIDATES OBSERVED BY Kepler. VIII. A FULLY AUTOMATED CATALOG WITH MEASURED COMPLETENESS AND RELIABILITY BASED ON DATA RELEASE 25 Susan E. Thompson,1, 2, 3, ∗ Jeffrey L. Coughlin,2, 1 Kelsey Hoffman,1 Fergal Mullally,1, 2, 4 Jessie L. Christiansen,5 Christopher J. Burke,2, 1, 6 Steve Bryson,2 Natalie Batalha,2 Michael R. Haas,2, y Joseph Catanzarite,1, 2 Jason F. Rowe,7 Geert Barentsen,8 Douglas A. Caldwell,1, 2 Bruce D. Clarke,1, 2 Jon M. Jenkins,2 Jie Li,1 David W. Latham,9 Jack J. Lissauer,2 Savita Mathur,10 Robert L. Morris,1, 2 Shawn E. Seader,11 Jeffrey C. Smith,1, 2 Todd C. Klaus,2 Joseph D. Twicken,1, 2 Jeffrey E. Van Cleve,1 Bill Wohler,1, 2 Rachel Akeson,5 David R. Ciardi,5 William D. Cochran,12 Christopher E. Henze,2 Steve B. Howell,2 Daniel Huber,13, 14, 1, 15 Andrej Prša,16 Solange V. Ramírez,5 Timothy D. Morton,17 Thomas Barclay,18 Jennifer R. Campbell,2, 19 William J. Chaplin,20, 15 David Charbonneau,9 Jørgen Christensen-Dalsgaard,15 Jessie L. Dotson,2 Laurance Doyle,21, 1 Edward W. Dunham,22 Andrea K. Dupree,9 Eric B. Ford,23, 24, 25, 26 John C. Geary,9 Forrest R. Girouard,27, 2 Howard Isaacson,28 Hans Kjeldsen,15 Elisa V. Quintana,18 Darin Ragozzine,29 Avi Shporer,30 Victor Silva Aguirre,15 Jason H. Steffen,31 Martin Still,8 Peter Tenenbaum,1, 2 William F.
    [Show full text]
  • Recipe for a Habitable Planet
    Recipe for a Habitable Planet Aomawa Shields Clare Boothe Luce Associate Professor Shields Center for Exoplanet Climate and Interdisciplinary Education (SCECIE) University of California, Irvine ASU School of Earth and Space Exploration (SESE) December 2, 2020 A moment to pause… Leading effectively during COVID-19 • Employees Need Trust and Compassion: Be Present, Even When You're Distant • Employees Need Stability: Prioritize Wellbeing Amid Disruption • Employees Need Hope: Anchor to Your "True North" From “3 strategies for leading effectively during COVID-19” (https://www.gallup.com/workplace/306503/strategies-leading-effectively-amid-covid.aspx) Hobbies: reading movies, shows knitting mixed media/collage violin tea yoga good restaurants spa days the beach hiking smelling flowers hanging with family BINGO Ill. Niklas Elmehed. Ill. Niklas Elmehed. © Nobel Media. © Nobel Media. RadialVelocity (m/s) Nobel Prize in Physics 2019 Mayor & Queloz 1995 https://exoplanets.nasa.gov/ As of December 2, 2020 Aomawa Shields Recipe for a Habitable World Credit: NASA NNASA’sASA’s KKeplerepler MMissionission TESS Transiting Exoplanet Survey Satellite Credit: NASA-JPL/Caltech Proxima Centauri b Credit: ESO/M. Kornmesser LHS 1140b Credit: ESO TOI 700d Credit: NASA TESS planets in the Earth-sized regime Credit: NASA’s Goddard Space Flight Center Which ones do we follow up on? 20 The Habitable Zone (Kasting et al. 1993, Kopparapu et al. 2013) ) Runaway greenhouse Maximum CO2 greenhouse Stellar Mass (M Mass Stellar Distance from Star (AU) Snowball Earth Many factors can affect planetary habitability Aomawa Shields Recipe for a Habitable World Liquid water Aomawa Shields Recipe for a Habitable World Isotopic Birth Tides Orbit Abundance Environ.
    [Show full text]
  • Erosion of an Exoplanetary Atmosphere Caused by Stellar Winds J
    A&A 630, A52 (2019) https://doi.org/10.1051/0004-6361/201935543 Astronomy & © ESO 2019 Astrophysics Erosion of an exoplanetary atmosphere caused by stellar winds J. M. Rodríguez-Mozos1 and A. Moya2,3 1 University of Granada (UGR), Department of Theoretical Physics and Cosmology, 18071 Granada, Spain 2 School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK e-mail: [email protected]; [email protected] 3 Stellar Astrophysics Centre, Department of Physics and Astronomy, Aarhus University, Ny Munkegade 120, 8000 Aarhus C, Denmark Received 26 March 2019 / Accepted 8 August 2019 ABSTRACT Aims. We present a formalism for a first-order estimation of the magnetosphere radius of exoplanets orbiting stars in the range from 0.08 to 1.3 M . With this radius, we estimate the atmospheric surface that is not protected from stellar winds. We have analyzed this unprotected surface for the most extreme environment for exoplanets: GKM-type and very low-mass stars at the two limits of the habitable zone. The estimated unprotected surface makes it possible to define a likelihood for an exoplanet to retain its atmosphere. This function can be incorporated into the new habitability index SEPHI. Methods. Using different formulations in the literature in addition to stellar and exoplanet physical characteristics, we estimated the stellar magnetic induction, the main characteristics of the stellar wind, and the different star-planet interaction regions (sub- and super- Alfvénic, sub- and supersonic). With this information, we can estimate the radius of the exoplanet magnetopause and thus the exoplanet unprotected surface.
    [Show full text]
  • Early Mars As a Key to Understanding Planetary Habitability
    Early Mars as a Key to Understanding Planetary Habitability Bethany Ehlmann Professor of Planetary Science, Geological & Planetary Sciences Research Scientist, Jet Propulsion Laboratory California Institute of Technology July 13, 2017 | Midterm Review Planetary Decadal Survey Outline: Early Mars as a Key to Understanding Planetary Habitability • What we have learned and what we can learn about early Mars [15 min] • Suggested exploration plans [5 min] • Questions/Discussion [10 min] Key Discoveries in Mars Science since 2010 *Publication date of last Mars references in V&V • Extent and diversity of potential ancient habitats (lakes, rivers, aquifers, hydrothermal systems, soil formation) • Mafic, Ultramafic, and Felsic igneous rocks • Modern liquid water • Recent Ice Ages and Episodicity of Climates above the Triple Point of Water • Modern active methane, likely with local sources • Modern active surface processes • Modern atmospheric loss rates See also MEPAG report to V&V Decadal Midterm (May 4, 2017): https://mepag.jpl.nasa.gov/meeting/2017-07/MEPAG_Johnson_MTDS_v04.pdf Key Discoveries in Mars Science since 2010 *Publication date of last Mars references in V&V • Extent and diversity of potential ancient habitats (lakes, Ancient rivers, aquifers, hydrothermal systems, soil formation) • Mafic, Ultramafic, and Felsic igneous rocks • Modern liquid water • Recent Ice Ages and Episodicity of Climates above the Triple Point of Water [see also Byrne talk, next] • Modern active methane, likely with local sources • Modern active surface processes • Modern atmospheric loss rates [see Jakosky talk, next] Modern See also MEPAG report to V&V Decadal Midterm (May 4, 2017): https://mepag.jpl.nasa.gov/meeting/2017-07/MEPAG_Johnson_MTDS_v04.pdf Key Finding since V&V: Modern Mars is active (methane, geomorphology, ice, water) Bridges et al., 2011; 2012 Mass wasting of the N.
    [Show full text]
  • The Tessmann Planetarium Guide to Exoplanets
    The Tessmann Planetarium Guide to Exoplanets REVISED SPRING 2020 That is the big question we all have: Are we alone in the universe? Exoplanets confirm the suspicion that planets are not rare. -Neil deGrasse Tyson What is an Exoplanet? WHAT IS AN EXOPLANET? Before 1990, we had not yet discovered any planets outside of our solar system. We did not have the methods to discover these types of planets. But in the three decades since then, we have discovered at least 4158 confirmed planets outside of our system – and the count seems to be increasing almost every day. We call these worlds exoplanets. These worlds have been discovered with the help of new and powerful telescopes, on Earth and in space, including the Hubble Space Telescope (HST). The Kepler Spacecraft (artist’s conception, below) and the Transiting Exoplanet Survey Satellite (TESS) were specifically designed to hunt for new planets. Kepler discovered 2662 planets during its search. TESS has discovered 46 planets so far and has found over 1800 planet candidates. In Some Factoids: particular, TESS is looking for smaller, rocky exoplanets of nearby, bright stars. An earth-sized planet, TOI 700d, was discovered by TESS in January 2020. This planet is in its star’s Goldilocks or habitable zone. The planet is about 100 light years away, in the constellation of Dorado. According to NASA, we have discovered 4158 exoplanets in 3081 planetary systems. 696 systems have more than one planet. NASA recognizes another 5220 unconfirmed candidates for exoplanets. In 2020, a student at the University of British Columbia, named Michelle Kunimoto, discovered 17 new exoplanets, one of which is in the habitable zone of a star.
    [Show full text]