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Renyu Hu

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Address:

4800 Oak Grove Drive
M/S 169-237

Pasadena, CA 91109

Phone:

818.354.6090

Fax:

818.393.4445

Curriculum Vitae:

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Website:

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Member of:

Exoplanet Discovery and Science

Biography

Dr. Renyu Hu is an expert in the physical and chemical processes, evolution, radiative transfer, and remote sensing of planetary and exoplanetary atmospheres. Dr. Hu received his Ph.D. in planetary science from the Massachusetts Institute of Technology in 2013, and joined JPL as a research scientist in 2015. Dr. Hu developed, from the first principles, a general-purpose photochemical and thermochemical model for exploring the diversity of exoplanets, which has led to the first classification framework of mini-Neptunes, a search strategy for helium-atmosphere exoplanets, and the prediction of an O2-CO runaway state on M stars' rocky planets. He also pioneered the method to detect minerals on bare-rock exoplanet surfaces. In addition to exoplanets, Dr. Hu uses stable isotopes to study the evolution of planetary atmospheres. For example, his research has led to evidence for a moderately dense early atmosphere on Mars, probably having a substantial fraction of nitrogen. Through these and many other research projects, Dr. Hu's research group has played a significant role in both the deep characterization of exoplanets and the debate on the ancient climate of Mars, leading multiple efforts to characterize exoplanets using Hubble, Spitzer, TESS, and JWST. Dr. Hu is a member of the Science, Technology, and Architecture Review Team (START) of the Habitable Worlds Observatory, and is leading the “Characterizing Exoplanets” sub working group. Dr. Hu is the Starshade Scientist of the NASA Exoplanet Exploration Program, providing scientific leadership to the Starshade Technology Development to TRL-5 (S5) activity.

Education

  • Ph.D. Planetary Science, Massachusetts Institute of Technology (2013)
  • M.S. Astrophysics, Tsinghua University (2009)
  • Diplome d'Ingenieur, Ecole Centrale Paris (2009)
  • B.S. Mathematics and Physics, Tsinghua University (2007)

Professional Experience

  • Jet Propulsion Laboratory
    • Research Scientist (2015-present)
    • Hubble Postdoctoral Fellow (2013-2015)
  • California Institute of Technology
    • Assistant Scientist (2013)

Space Mission Experience

  • Founder and Co-Lead of ExoPAG Study Analysis Group on exoplanet reflection spectroscopy for the Habitable Worlds Observatory
  • Member of NASA Science, Technology, Architecture Review Team (START) for the Habitable Worlds Observatory
    • Chartered to quantify the science objectives and guide the technology maturation program
    • Co-chair of the “Characterizing Exoplanets” sub working group
    • Steering Committee of the “Exoplanet Science Yield” working group
  • Starshade Scientist of NASA Exoplanet Exploration Program
    • Provided science leadership to the Starshade Technology Development to TRL-5 (S5) project and managed a national-level and community-facing Starshade Science and Industry Partnership program
    • Led a team of 6 scientists and engineers to formulate, develop, and conduct the Starshade Exoplanet Data Challenge, and managed the acquisition of two external participating teams through a proposal process
  • Atmospheric Science Lead of Starshade Rendezvous Probe concept study and Roman Space Telescope starshade accommodation study
  • Member of New Frontier 5 Venus Climate/Geophysics mission concept team
  • Member of TESS Atmospheric Characterization Working Group
  • Member of WFIRST (Roman) Coronagraph Science Investigation Teams
  • Collaborator of Ultraviolet Explorer (UVEX), a Medium-Class Explorer (MIDEX) mission
  • Co-chair, exoplanet working group of the Uranus flagship mission concept team

Community Service

  • Reviewer for Science, Nature, Nature Geoscience, Nature Astronomy, PNAS, ApJ, ApJS, A&A, MNRAS, EPSL, GRL, JGR, Icarus, and Astrobiology
  • Panel Reviewer for NASA Planetary Atmospheres Program, NASA Mars Data Analysis Program, NASA Exoplanets Research Program, NASA Astrophysics Research and Analysis Program, NASA Hubble Postdoctoral Fellowship, NSF Astronomy and Astrophysics Postdoctoral Fellowship, and NASA Earth and Space Science Fellowship
  • Founder of JPL Exoplanet Lunch Seminar Series
  • Member of NASA ExoPAG Study Analysis Group 15 on Science Questions for Direct Imaging Exoplanet Missions
  • Member of NASA ExoPAG Study Analysis Group 16 on Exoplanet Biosignatures
  • Chair of JPL Astrophysics Return to Lab Working Group
  • Chair of JPL Astrophysics Colloquium Committee
  • Panel Member of Hubble Space Telescope Time Allocation Committee Cycles 23, 28, and 30
  • Reviewer of James Webb Space Telescope Time Allocation Committee Cycle 2



Research Interests

  • Atmospheres of planets and exoplanets from Earth-sized to Jupiter-sized
  • Remote sensing of planets using transit spectroscopy, phase curve mapping, and direct imaging
  • Evolution of planetary atmospheres and stable isotope geochemistry
  • Search for habitable planets and biosignatures
  • Gas and aqueous phase chemical kinetics

Selected Awards

  • JPL Edward Stone Award for Outstanding Research Publication
  • NASA Early Career Public Achievement Medal
  • NASA Group Achievement Award for the Astrophysics Large Mission Studies (2019)
  • JPL Voyager Award for Individual Achievement (2017)
  • NASA Hubble Fellowship (2013)
  • Barrett Prize, MIT (2012)
  • NASA Earth and Space Science Fellowship (2011)
  • Presidential Fellowship, MIT (2009)
  • Wu You-Xun Prize, Tsinghua University (2009)
  • Scialog Fellow, Research Corporation for Science Advancement

Selected Publications

  1. Michael Zhang, Renyu Hu, et al. (2024), GJ 367b is a dark, hot, airless sub-Earth, ApJ Letters, 961, L44
  2. Mario Damiano, Renyu Hu, and Bertrand Mennesson (2023), Reflected Spectroscopy of Small Exoplanets. III. Probing the UV Band to Measure Biosignature Gases, AJ, 166, 157
  3. Renyu Hu, Fabrice Gaillard, and Edwin Kite (2023), Narrow loophole for H2-dominated atmospheres on habitable rocky planets around M dwarfs, ApJ Letters, 948, L20
  4. Trent Thomas, Renyu Hu, and Daniel Y. Lo (2023), Constraints on the size and composition of the ancient Martian atmosphere from coupled CO2-N2-Ar isotopic evolution models, PSJ, 4, 41
  5. JWST Transiting Exoplanet Community Early Release Science Team (2023), Identification of carbon dioxide in an exoplanet atmosphere, Nature, 614, 649
  6. Mario Damiano and Renyu Hu (2022), Reflected spectroscopy of small planets II: characterization of terrestrial exoplanets, AJ, 163, 299
  7. Renyu Hu and Trent Thomas (2022), A nitrogen-rich atmosphere on ancient Mars consistent with isotopic evolution models, Nature Geoscience, 15, 106
  8. Mario Damiano and Renyu Hu (2021), Reflected spectroscopy of small exoplanets I: determining the atmospheric composition of sub-Neptune planets, AJ, 162, 200
  9. Renyu Hu, Mario Damiano, Markus Scheucher, Edwin Kite, Sara Seager, and Heike Rauer (2021), Unveiling shrouded oceans on temperate sub-Neptunes via transit signatures of solubility equilibria vs. gas thermochemistry, ApJ Letters, 921, L8
  10. Renyu Hu (2021), Photochemistry and Spectral Characterization of Temperate and Gas-Rich Exoplanets, ApJ, 921, 27
  11. Eva L. Scheller, Bethany Ehlmann, Renyu Hu, Danica Adams, and Yuk Yung (2021), Long-Term Drying of Mars by Sequestration of Ocean-Scale Volumes of Water in the Crust, Science, 372, 56
  12. Renyu Hu, Doug Lisman, Stuart Shaklan, Stefan Martin, Phil Willems, and Kendra Short (2021), Overview and Reassessment of Noise Budget of Starshade Exoplanet Imaging, Journal of Astronomical Telescopes, Instruments, and Systems, 7, 021205
  13. Mario Damiano, Renyu Hu, and Sergi Hildebrandt (2020), Multi-orbital-phase and Multiband Characterization of Exoplanetary Atmospheres with Reflected Light Spectra, AJ, 160, 206
  14. Mario Damiano and Renyu Hu (2020), ExoREL-R: A Bayesian Inverse Retrieval Framework for Exoplanetary Reflected Light Spectra, AJ, 159, 175
  15. Renyu Hu, Luke Peterson, and Eric T. Wolf (2020), O2-Dominated Atmospheres for Potentially Habitable Environments on TRAPPSIT-1 Planets, ApJ, 888, 122
  16. Clara Sousa-Silva, Sara Seager, Sukrit Ranjan, Janusz Petkowski, Zhuchang Zhan, Renyu Hu, and William Bains (2020), Phosphine as a Biosignature Gas in Exoplanet Atmospheres, Astrobiology, 20, 2
  17. Renyu Hu (2019), Information in the Reflected Light Spectra of Widely Separated Giant Exoplanets, ApJ, 887, 166
  18. Renyu Hu and Héctor Delgado Diaz (2019), Stability of Nitrogen in Planetary Atmospheres in Contact with Liquid Water, ApJ, 886, 126
  19. Megan Mansfield, Edwin S. Kite, Renyu Hu, Daniel Koll, Matej Malik, Jacob Bean, and Eliza Kempton (2019), Identifying Atmospheres on Rocky Exoplanets through Infrared High Albedo, ApJ, 886, 141
  20. Laura Kreidberg, Daniel Koll, Caroline Morley, Renyu Hu, Laura Schaefer, Drake Deming, Kevin B. Stevenson, Jason Dittmann, Andrew Vanderburg, Berardo, Xueying Guo, Keivan Stassun, Ian Crossfield, David Charbonneau, David W. Latham, Abraham Loeb, George Ricker, Sara Seager, and Roland Vanderspek (2019), Absence of a thick atmosphere on the terrestrial exoplanet LHS 3844b, Nature, 573, 87
  21. Jonathan Jiang, Xuan Ji, Nicholas Cowan, Renyu Hu, and Zonghong Zhu (2019), Empirical Predictions for the Period Distribution of Planets to be Discovered by the Transiting Exoplanet Survey Satellite, AJ, 158, 96
  22. Renyu Hu (2019), Predicted Diurnal Variation of the Deuterium to Hydrogen Ratio in Water at the Surface of Mars Caused by Mass Exchange with the Regolith, Earth Planet Sci Lett, 519, 192
  23. Yui Kawashima, Renyu Hu, and Masahiro Ikoma (2019), Detectable molecular features above hydrocarbon haze via transmission spectroscopy with JWST: Case studies of GJ 1214b, GJ 436b, HD 97658b, and Kepler-51b, ApJ Letters, 876, L5
  24. R. O. Parke Loyd, Kevin France, Allison Youngblood, Christian Schneider, Alexander Brown, Renyu Hu, Antígona Segura, Jeffrey Linsky, Seth Redfield, Feng Tian, Sarah Rugheimer, Yamila Miguel, and Cynthia S. Froning (2018), The Muscles Treasury Survey. V. FUV Flares On Active And Inactive M Dwarfs, ApJ, 867, 71
  25. Tre’Shunda James and Renyu Hu (2018), Photochemical Oxygen in Non-1 Bar CO2 Atmospheres of Terrestrial Exoplanets, ApJ, 867, 17
  26. Chester E. Harman, Ryan Felton, Renyu Hu, Shawn Domagal-Goldman, Antígona Segura, Feng Tian, and James Kasting (2018), Abiotic O2 Levels on Planets around F, G, K, and M Stars: Effects of Lightning-Produced Catalysts in Eliminating Oxygen False Positives, ApJ, 866, 56
  27. Ji Wang, Dimitri Mawet, Renyu Hu, Garreth Ruane, Jacques-Robert Delorme, and Nikita Klimovich (2018), Baseline Requirements for Detecting Biosignatures with the HabEx and LUVOIR Mission Concepts, Journal of Astronomical Telescopes, Instruments, and Systems, 4, 035001
  28. Jonathan Jiang, Albert Zhai, Jay Herman, Chengxing Zhai, Renyu Hu, Hui Su, Vijay Natraj, Jiazheng Li, Feng Xu, and Yuk L. Yung (2018), Using Deep Space Climate Observatory Measurements to Study the Earth as An Exoplanet, AJ, 156, 26
  29. Isabel Angelo and Renyu Hu (2017), A Case for an Atmosphere on Super-Earth 55 Cancri e, AJ, 154, 6
  30. Ji Wang, Dimitri Mawet, Garreth Ruane, Renyu Hu, and Björn Benneke (2017), Observing Exoplanets with High Dispersion Coronagraphy. I. The scientific potential of current and next-generation large ground and space telescopes, AJ, 153, 183
  31. Renyu Hu, Anthony Bloom, Peter Gao, Charles E. Miller, and Yuk L. Yung (2016), Hypotheses for near-surface exchange of methane on Mars, Astrobiology, 16, 539
  32. Brice-Oliver Demory, Michael Gillon, Julien de Wit, Nikku Madhusudhan, Emeline Bolmont, Kevin Heng, Tiffany Kataria, Nikole Lewis, Renyu Hu, Jessican Krick, Vlada Stamenkovic, Björn Benneke, Stephen Kane, and Didier Queloz (2016), A map of the large day-night temperature gradient of a super-Earth exoplanet, Nature, 532, 207
  33. Renyu Hu, David Kass, Bethany L. Ehlmann, and Yuk L. Yung (2015), Tracing the Fate of Carbon and the Atmospheric Evolution of Mars, Nature Communications, 6, 10003
  34. Renyu Hu, Sara Seager, and Yuk L. Yung (2015),  Helium Atmospheres on Warm Neptune- and Sub-Neptune-Sized Exoplanets and Applications to GJ 436 b, ApJ, 807, 8
  35. Renyu Hu, Brice-Olivier Demory, Sara Seager, Nikole Lewis, and Adam P. Showman (2015), A Semi-Analytical Model of Visible-Wavelength Phase Curves of Exoplanets and Applications to Kepler-7 b and Kepler-10 b, ApJ, 802, 51
  36. Avi Shporer and Renyu Hu (2015), Studying Atmosphere-Dominated Kepler Phase Curves, AJ, 150, 4
  37. Peter Gao, Renyu Hu, Tyler Robinson, Cheng Li, and Yuk L. Yung (2015), Stabilization of CO2 Atmospheres on Exoplanets around M Dwarf Stars, ApJ, 806, 249
  38. Renyu Hu, and Sara Seager (2014), Photochemistry in Terrestrial Exoplanet Atmospheres III: Photochemistry and Thermochemistry in Thick Atmospheres on Super Earths, ApJ, 784, 63
  39. Renyu Hu, Sara Seager, and William Bains (2013), Photochemistry in Terrestrial Exoplanet Atmospheres II: H2S and SO2 Photochemistry in Anoxic Atmospheres, ApJ, 769, 6
  40. Renyu Hu, Sara Seager, and William Bains (2012), Photochemistry in Terrestrial Exoplanet Atmospheres I: Photochemistry Model and Benchmark Cases, ApJ 761, 166
  41. Renyu Hu, Kerri Cahoy, and Maria T. Zuber (2012), Mars CO2 Condensation Above The North and South Poles Revealed by Radio Occultation, Climate Sounding, and Laser Ranging, JGR, 117, E07002
  42. Renyu Hu, Bethany L. Ehlmann, and Sara Seager (2012), Theoretical Spectra of Terrestrial Exoplanet Surfaces, ApJ, 752, 7.
  43. Renyu Hu (2010), Transport of the First Rocks of the Solar System by X-winds, ApJ, 725, 1421
  44. Renyu Hu and Yu-Qing Lou (2009), Magnetic Massive Stars as Magnetar Progenitors, MNRAS, 396, 878
  45. Renyu Hu, Yulia V. Bogdanova, Christopher J. Owen, Claire Foullon, Andrew N. Fazakerley, and Henri Rème (2008), Cluster Observations of the Mid-Altitude Cusp under Strong Northward Interplanetary Magnetic Field, JGR, 113, A07S05

Projects

Nancy Grace Roman Space Telescope
Starshade
TESS