Dr. Vishnu Viswanathan’s research is focused on the analysis of tracking data such as radio, laser and images, to determine the geophysical, orbital, and rotational properties of planetary bodies. In 2017, Dr. Viswanathan improved the orbital-rotational dynamical model of the Moon and fitted it to over five decades of lunar laser ranging (LLR) data with gravity field constraints from the NASA GRAIL mission. This model is one of the three primary references in the world that provides high-precision planetary and lunar ephemerides. In 2018, Dr. Viswanathan used this model to perform a fundamental physics test of the universality of free fall using the Earth-Moon system as test bodies, improving upon previous constraints on the principle of equivalence. In 2019, Dr. Viswanathan further expanded the capabilities of this model resulting in the strongest constraint known for the shape and size of the lunar core-mantle boundary. In 2020, Dr. Viswanathan published two white papers submitted to the Committee on the Planetary Science Decadal Survey (2023-2032) of the National Academies of Sciences/USA, and to the Artemis III Science Definition Team, representing the interests, objectives and goals of the global LLR instrument, data analysis and observer community. In 2022, Dr. Viswanathan founded a Lunar Data Analysis Center at UMBC/NASA GSFC affiliated with the International Laser Ranging Service, and he is involved in inter-agency activities related to the US Lunar Reference System components. Dr. Viswanathan is currently at NASA GSFC employed by UMBC under the CRESST II cooperative agreement.
Vishnu Viswanathan
(ASSISTANT RESEARCH SCIENTIST)
| Email: | vishnu.viswanathan@nasa.gov |
| Phone: | 301.614.6466 |
| Org Code: | 698 |
| Address: |
NASA/GSFC Mail Code 698 Greenbelt, MD 20771 |
| Employer: | UMBC Univ. of MD, Baltimore |
Missions & Projects
Brief Bio
Positions/Employment
Asst. Research Scientist
NASA Goddard Space Flight Center | UMBC CRESST II - Greenbelt, MD, USA
August 2021 - Present
Post-doctoral Research Associate
NASA Goddard Space Flight Center | UMBC CRESST II - Greenbelt, MD, USA
April 2019 - August 2021
Post-doctoral Researcher
Institut de Méchanique Céleste et de Calcul des Éphéphérides (IMCCE), Observatoire de Paris - Paris, France
November 2017 - March 2019
Research Engineer
Centre National de la Recherche Scientifique (CNRS) - Sophia Antipolis, France
October 2017 - November 2017
Doctoral researcher
Observatoire de Paris & Observatoire de la Côte d'Azur - France
October 2014 - September 2017
Education
Ph.D. 2017, Astronomy and Astrophysics, Observatoire de Paris - France, "Improving the dynamical model of the Moon using lunar laser ranging (LLR) and spacecraft data", Supervisors: Prof. Agnès Fienga and Prof. Jacques Laskar
M.S. 2013, Space Systems Engineering, Institut Supérieur de l'Aéronautique et de l'Espace, Toulouse - France, "Emulation of a geostationary channel using software-defined radio platform", Supervisor: Prof. Laurent Franck
B.Tech. 2011, Electronics and Communication Engineering, National Institute of Technology, Trichy - India
Professional Societies
American Geophysical Union
Affiliate
2019 - Present
European Geophysical Union
Affiliate
2016 - Present
Division for Planetary Science
Affiliate
2021 - Present
International Laser Ranging Service
Associate member
2022 - Present
Professional Service
Reviewer for ApJL, A&A, ASR, CMDA, ESS, Icarus, JGeod, JGR:Pla, PSJ, Remote Sensing, Universe
Reviewer for NASA HQ’s ROSES and EONS programs as Panel Chair/Panelist/External Reviewer
Grants
Independent Measurement of Saturn's Dissipation using Cassini Astrometric Data
Cassini Data Analysis Program - NASA HQ Science Mission Directorate (NNH20ZDA001N) - Awarded: 2020-09-28
Dates: 2021-03-01 - 2024-02-29
Study of the interior structure of the Moon using lunar laser ranging data
Post-doctoral research grant - LABEX Exploration Spatiale des Environments Planétaires - France - Awarded: 2017-11-15
Dates: 2017-11-15 - 2018-11-15
Coverage: 1.0
Improving the dynamical model of the Moon using lunar laser ranging (LLR) and spacecraft data
Doctoral research grant - Ministry of Higher Education, Research and Innovation - France - Awarded: 2014-10-01
Dates: 2014-10-01 - 2017-09-30
Coverage: 3.0
Publications
Refereed
2022. "The Contribution of Small Impact Craters to Lunar Polar Wander." The Planetary Science Journal 3 217 [10.3847/PSJ/ac8c39] [Journal Article/Letter]
2021. "A Recipe for the Geophysical Exploration of Enceladus." The Planetary Science Journal 2 (4): 157 [10.3847/psj/ac06d2] [Journal Article/Letter]
2020. "First Two-way Laser Ranging to a Lunar Orbiter: infrared observations from the Grasse station to LRO’s retro-reflector array ." Earth, Planets and Space [Full Text] [10.1186/s40623-020-01243-w] [Journal Article/Letter]
2019. "Observational constraint on the radius and oblateness of the lunar core-mantle boundary." Geophysical Research Letters 46 [10.1029/2019GL082677] [Journal Article/Letter]
2018. "The new lunar ephemeris INPOP17a and its application to fundamental physics." Monthly Notices of the Royal Astronomical Society 476 1877-1888 [10.1093/mnras/sty096] [Journal Article/Letter]
2017. "Lunar laser ranging in infrared at the Grasse laser station." Astronomy & Astrophysics 602 A90 [10.1051/0004-6361/201628590] [Journal Article/Letter]
Non-Refereed
2023. "Recent Developments at the Apache Point Lunar Laser Ranging Station." Proceedings of the 22nd International Workshop on Laser Ranging [Full Text] [Proceedings]
2021. "A Recipe for Geophysical Exploration of Enceladus." Bulletin of the American Astronomical Society 53 (4): [10.3847/25c2cfeb.b65f2c4c] [Journal Article/Letter]
2021. "Extending Science from Lunar Laser Ranging." Bulletin of the American Astronomical Society 53 (4): [10.3847/25c2cfeb.3dc2e5e4] [Journal Article/Letter]
2017. "INPOP17a planetary ephemerides." Notes Scientifiques et Techniques de l'Institut de mécanique céleste S108 [Full Text] [10.13140/RG.2.2.24384.43521] [Book]
2017. "Satellite and lunar laser ranging in infrared." Proceedings of the SPIE Conference on Photon Counting Applications, 2017 10229 UNSP 102290K [10.1117/12.2270573] [Proceedings]
Talks, Presentations and Posters
Invited
On the State of the Lunar Orientation: From Geological History to Modern-day Times
September 12, 2024
Invited by Dr. Susan Stewart (USNO) and Dr. Brent Archinal (USGS) to talk at the XXXII IAU General Assembly Division A Fundamental Astronomy | Lunar Standards about the state of the lunar orientation, covering geological time to modern-day observation. I presented work on the true polar wander of the Moon from >1M impact craters/basins down to 1 km diameter as informed by the high-resolution GRAIL gravity and LRO-LOLA topography datasets. I also showed evidence of substantial errors (>1m) propagated when transforming position coordinates from the JPL's DE440 lunar principal-axis (PA) frame to JPL's DE421 mean-Earth (ME) reference frame, raising caution on the usage of JPL's ME frames for applications requiring <1m surface accuracy on the Moon.
Recommendations on the Data, Models and Parameterization for Planning a Unified Lunar Geodetic System
August 18, 2024
In-depth presentation and discussion on Task #1 deliverable of the National Geospatial-Intelligence Agency (NGA)-NASA Inter-Agency Agreement (IAA) during the IAA close-out meeting held at NGA's Moonshot Labs, St. Louis, MO.
GRAIL-LLR Principal Axes Reference Frames
November 2023
Invited by the National Geospatial-Intelligence Agency's (NGA) Office of Geomatics (Space Branch) to present work and lead a discussion related to lunar reference frames realized from the analysis of GRAIL gravity and LLR data to members of the Lunar Geodetic System Working Group, consisting of ~180 members across USGOV, academia, and industry.
LLR and Lunar Reference Frames
July 2023
Invited by the National Geospatial-Intelligence Agency's (NGA) Office of Geomatics (Space Branch) for discussions regarding the realization of a lunar reference frame using LLR data analysis.
Lunar Laser Ranging Data Analysis
April 2023
Invited by the National Geospatial-Intelligence Agency's (NGA) Office of Geomatics (Space Branch) to present work on LLR data analysis to the Lunar Reference System Working Group.
Orientation of the Moon using Lunar Laser Ranging data & GRAIL gravity field
December 2022
Invited by NASA HQ/ESD to talk at the Scripps Institution of Oceanography, La Jolla, CA during the Solid Earth Team (SET) meeting (November 7-11; consisting of ~200 participants) organized by NASA Earth Surface and Interior (ESI) focus group.
Extending Science from Lunar Laser Ranging
May 2021
Joint Seminar: Geodesy & Geophysics Laboratory; Planetary Geology, Geophysics & Geochemistry Laboratory at NASA GSFC
Other
A Simulation Study for Extending Lunar Laser Ranging Science
April 2021
Poster presented at 52nd LPSC, #2651, 3/2021
Science Opportunities for Lunar Retro-Reflectors
August 2020
NASA Exploration Science Forum 2020, #NESF2020-078
Scientific Exploration of the Lunar South Pole with Retro-Reflectors
May 2020
Talk at Lunar Surface Science Workshop 2020
Estimating the Lunar Core Equatorial Ellipticity Using Lunar Laser Ranging
April 2020
Poster presentation at the 51st Lunar and Planetary Science Conference (2020), Texas, USA
On the GRAIL-LLR Low-Degree Gravity Field Inconsistencies
2019
Poster presented at AGU Fall Meeting 2019, San Francisco, USA
Updates from INPOP ephemeris: From fundamental physics tests to lunar interior probe.
August 2018
Talk at 42nd COSPAR Scientific Assembly (H0.5-0006-18)
Recent updates from the INPOP lunar and planetary ephemeris team.
July 2018
Talk at Journées Scientifiques du Programme National GRAM (215219)
May 2017
Poster presented at EGU General Assembly Conference (Vol. 19, p. 7450)
Infrared Lunar Laser Ranging at Calern: Impact on Lunar Dynamics.
April 2017
Poster presented at Lunar and Planetary Science Conference (Vol. 48, p. 2329)
LLR data analysis and impact on lunar dynamics from recent developments at OCA LLR Station.
May 2016
Talk at EGU General Assembly Conference Abstracts (Vol. 18, p. 13995)
Teaching Experience
"Principles of Thermodynamics", Undergraduate level, ESAIP Graduate School of Engineering, Grasse - France
"Satellite systems", Graduate level, University of Nice, Sophia Antipolis
Selected Public Outreach
Science Update: From Apollo to Artemis, Get Ready for International Observe the Moon Night!
August 2024 - August 2024
Staci Tiedeken (NASA/GSFC) and I presented a talk at the Science Update webinar series hosted by the National Science Teaching Association (NSTA), highlighting the upcoming International Observe the Moon Night and the field of planetary geodesy, to a ~65-member audience consisting of teachers of science and general science enthusiasts. During the talk, I covered the critical role of lunar laser ranging data behind scientific discoveries about the Moon's interior structure and how it also goes on to help millions of people plan their trips around solar eclipses! I also had the honor of sharing updates and the excitement around NASA's Artemis missions. A recording of the event is available here.
"How bouncing lasers off the Moon paves the road to lunar science and exploration"
May 2023 - May 2023
I served as the keynote speaker for a NASA Goddard Visitor Center symposium involving nearly 110 high school students from MA/NY/NJ presenting their work on challenges in building a sustainable presence of humans on the Moon, followed by Q&A with the students and feedback on their work.
“Episode 42 – Watch a Total Lunar Eclipse”, NASA Science Live, May 15, 2022
June 2022 - June 2022
I was invited to participate along with Dr. Ryan Watkins (NASA/HQ) in this live stream organized by NASA to talk about my role and support Q&A from the public regarding lunar science and exploration in the Artemis era.
50th Anniversary of the Apollo Moon landing, National Mall
August 2019 - August 2019
Volunteering work at the Moon Tours (Moon trek + LRO) tent using lunar topographic data, 3D prints of the lunar surface and lunar simulant samples.