Year: 2019
Type: article
Abstract: Most rocky planets in the galaxy orbit a cool host star, and there is large uncertainty among theoretical models whether these planets can retain an atmosphere. The James Webb Space Telescope ( JWST ) might be able to settle this question empirically, but most proposals for doing so require large observational effort because they are based on spectroscopy. Here we show that infrared photometry of secondary eclipses could quickly identify “candidate” atmospheres, by searching for rocky planets with atmospheres thick enough that atmospheric heat transport noticeably reduces their dayside thermal emission compared to that of a bare rock. For a planet amenable to atmospheric follow-up, we find that JWST should be able to confidently detect the heat redistribution signal of an bar atmosphere with one to two eclipses. One to two eclipses is generally much less than the effort needed to infer an atmosphere via transmission or emission spectroscopy. Candidate atmospheres can be further validated via follow-up spectroscopy or phase curves. In addition, because this technique is fast it could enable a first atmospheric survey of rocky exoplanets with JWST . We estimate that the TESS mission will find ∼100 planets that are too hot to be habitable but that can be quickly probed via eclipse photometry. Knowing whether hot, rocky planets around M dwarfs have atmospheres is important not only for understanding the evolution of uninhabitable worlds: if atmospheres are common on hot planets, then cooler, potentially habitable planets around M dwarfs are also likely to have atmospheres.
Source: The Astrophysical Journal
Authors: Daniel D. B. Koll, Matej Malik, Megan Mansfield, Eliza M.-R. Kempton, Edwin Kite, Dorian Abbot, Jacob L. Bean
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: bronze
Awards: CAREER: Modeling of Super-Earth Atmospheres - Looking Toward the James Webb Space Telescope and Beyond, Combined Modeling of Exoplanetary Atmospheres, ORIGIN OF THE VOLATILE ENVELOPES OF SMALL-RADIUS EXOPLANETS SECTION UNDERSTANDING THE ORIGIN OF THE VOLATILES IS FUNDAMENTAL TO THE INTERPRETATION OF, TO ENABLE AND ADVANCE NASA S SEARCH FOR LIFE BEYOND THE SOLAR SYSTEM THE VIRTUAL PLANETARY LABORATORY TEAM WILL FOCUS ON A COMPELLING SCIENTIFIC QUESTION: HOW DO WE RECOGNIZE WHETHER AN EXOPLANET CAN OR DOES SUPPORT LIFE? IN ADVANCE OF CHALLENGING OBSERVATIONS THE VPL WILL COMBINE SCIENTIFIC MODELS OBSERVATIONS AND FIELD AND LABORATORY DATA FROM MANY DISCIPLINES TO EXPLORE HOW A PLANET BECOMES AND REMAINS HABITABLE AND IDENTIFY NEW BIOSIGNATURES IN THE CONTEXT OF THEIR ENVIRONMENTS. THIS RESEARCH WILL INFORM TARGET SELECTION FOR JWST FROM K2 TESS AND GROUND-BASED EXOPLANET DISCOVERIES; HELP OBSERVERS RECOGNIZE THE SIGNS OF PLANETARY HABITABILITY AND LIFE; AND INFORM UPCOMING NASA MISSIONS THAT WILL OBSERVE TERRESTRIAL EXOPLANETS SUCH AS JWST AND THE HABEX OST AND LUVOIR MISSION CONCEPTS. FIVE RESEARCH TASKS WILL ADDRESS OUR SCIENTIFIC QUESTION. TASKS A-D PROVIDE A SUITE OF SELF-CONSISTENT PLANETARY ENVIRONMENTS BASED ON DATA AND MODELS THAT ARE VALIDATED AGAINST SOLAR SYSTEM PLANETS. THESE PLANETARY ENVIRONMENTS ARE THEN INPUT TO TASK E TO SIMULATE PLANETARY OBSERVATIONS AND DETERMINE THE DETECTABILITY OF SIGNS OF HABITABILITY AND LIFE. TASK A: SOLAR SYSTEM ANALOGS FOR EXOPLANETS. WE WILL USE OBSERVATIONS AND ATMOSPHERIC MODELS OF EARTH AND VENUS AS WELL AS REALISTIC SIMULATIONS OF THE DISTANT SOLAR SYSTEM AND OTHER PLANETARY SYSTEMS TO EXPLORE PROCESSES AND REMOTE-SENSING DISCRIMINANTS RELEVANT TO HABITABLE ENVIRONMENTS BIOSIGNATURES AND FALSE POSITIVES. TASK B: THE EARTH THROUGH TIME. WE WILL UNDERTAKE AN INTERDISCIPLINARY SYNTHESIS OF FIELD LABORATORY AND MODELING EFFORTS TO CONSTRAIN ENVIRONMENTAL ECOLOGICAL AND REMOTELY OBSERVABLE PARAMETERS OF EARLY EARTH AND SIMILAR EXOPLANETS AROUND OTHER STARS AS A FUNCTION OF DOMINANT METABOLISM. TASK C: THE HABITABLE PLANET. WE WILL DEVELOP AND USE COUPLED STELLAR ORBITAL INTERIOR AND 1-D TO 3-D ATMOSPHERIC MODELS TO EXPLORE TERRESTRIAL EXOPLANET FORMATION DYNAMICS COMPOSITION ATMOSPHERIC EVOLUTION AND HABITABILITY. THESE ANALYSES WILL INFORM HABITABILITY ASSESSMENTS TO PRIORITIZE PROMISING EXOPLANETS FOR BIOSIGNATURE SEARCHES. TASK D: THE LIVING PLANET. WE WILL INTEGRATE FIELD AND LABORATORY RESEARCH WITH COUPLED CHEMICAL CLIMATE AND ECOSYSTEM MODELS TO EXPLORE THE NATURE AND DETECTABILITY OF BIOSIGNATURES FOR DIFFERENT GEOCHEMICAL AND STELLAR ENVIRONMENTS. WE WILL IDENTIFY NEW REMOTESENSING ATMOSPHERIC SURFACE AND TEMPORAL BIOSIGNATURES AND THEIR FALSE POSITIVES AND NEGATIVES AND QUANTIFY THE ENVIRONMENTAL LIMITS TO PHOTOSYNTHETIC PRODUCTIVITY. TASK E: THE OBSERVER. WE WILL COMBINE OBSERVATIONS ANALYSIS TECHNIQUES AND SIMULATIONS TO IMPROVE THE DETECTION AND CHARACTERIZATION OF POTENTIALLY HABITABLE EXOPLANETS. WE WILL IMPROVE RETRIEVAL OF PLANETARY PROPERTIES FROM EXOPLANET MAPPING AND FROM DIRECT IMAGING TRANSIT TRANSMISSION AND HIGH-RESOLUTION SPECTROSCOPY. OUR ANALYSES WILL DETERMINE OPTIMAL MEASUREMENTS AND OBSERVATION STRATEGIES FOR TERRESTRIAL EXOPLANET CHARACTERIZATION. THE PROPOSED EFFORT BENEFITS ASTROBIOLOGY AND THE NAI WITH A PROVEN PRODUCTIVE INTERDISCIPLINARY SCIENCE TEAM WHOSE RESEARCH ADDRESSES KEY ASTROBIOLOGY PROGRAM GOALS INCLUDING CONSTRUCTING HABITABLE WORLDS IDENTIFYING EXPLORING AND CHARACTERIZING ENVIRONMENTS FOR HABITABILITY AND BIOSIGNATURES AND THE COEVOLUTION OF LIFE AND THE PHYSICAL ENVIRONMENT. THE UW S ASTROBIOLOGY DUAL-TITLE PHD PROGRAM AND OUR ASTROBIOLOGY RESEARCH OPPORTUNITIES FOR MINORITY UNDERGRADUATES STRONGLY SUPPORT THE TRAINING OF THE NEXT GENERATION OF ASTROBIOLOGISTS. OUR TEAM MEMBERS WILL CONTINUE TO PROVIDE KEY SCIENTIFIC LEADERSHIP FOR RELEVANT NASA MISSIONS. THE VPL WILL LEVERAGE THE MASSIVELY INTERDISCIPLINARY COLLABORATION ENABLED BY THE NAI TO PROVIDE A UNIQUE SYNTHESIS OF NASA PLANETARY AND EARTH SCIENCE MISSION DATA MODELING AND RETRIEVAL TECHNIQUES THAT INFORM AND SUPPORT NASA ASTROBIOLOGY AND ASTROPHYSICS MISSION OBJECTIVES.
OpenAlex ID: W2965599940