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Sarah Peacock Surveys Stellar Radiation to Hunt for Habitable Worlds


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Preparations for Next Moonwalk Simulations Underway (and Underwater)

Knowing whether or not a planet elsewhere in the galaxy could potentially be habitable requires knowing a lot about that planet’s sun. Sarah Peacock relies on computer models to assess stars’ radiation, which can have a major influence on whether or not one of these exoplanets has breathable atmosphere.

Name: Sarah Peacock

Title: Assistant Research Scientist

Formal Job Classification: Astrophysicist

Organization: Exoplanets and Stellar Astrophysics Laboratory, Astrophysics Division, Science Directorate (Code 667)

Sarah Peacock stands next to the worm logo at NASA Headquarters.
Sarah Peacock is a research scientist with the Exoplanets and Stellar Astrophysics Laboratory at NASA’s Goddard Space Flight Center in Greenbelt, Md.
Courtesy of Sarah Peacock

What do you do and what is most interesting about your role here at Goddard?

My overarching research goal is to find habitable planets in other solar systems. To do this, I study the high-energy radiation that specific stars produce to help determine if life can exist on any earthlike planets that orbit them.

What is your educational background?

In 2013, I received a Bachelor of Arts in astrophysics from the University of Virginia. I received both my master’s and doctorate degrees from the Lunar and Planetary Laboratory at the University of Arizona in 2016 and 2019, respectively.

What drew you to study the stars?

In high school, I took an astronomy class. We had a planetarium in our school and I had a wonderful teacher who inspired me to fall in love with the stars. She also showed us how many of the Harry Potter characters are drawn from the constellations and that spoke to my heart because I am a Harry Potter fan!

How did you come to Goddard?

I started at Goddard as a NASA post-doctoral fellow in July 2020, but I first saw the center the day before Goddard shut down due to COVID.

How does high-energy radiation show you what planets outside our solar system might be habitable?

High-energy radiation can cause a planet to lose its atmosphere. If a planet is exposed to too much high-energy radiation, the atmosphere can be blown off, and if there is no atmosphere, then there is nothing for life as we know it to breathe.

We cannot directly measure the specific radiation that I study, so we have to model it. The universe has so many stars, and almost all stars host a planet. There are approximately 5,500 confirmed exoplanets so far, with an additional 7,500 unconfirmed exoplanets.

I help identify systems that either have too much radiation, so planets in the habitable zone (the region around a star where liquid water could exist on a planet’s surface) are probably lifeless, or systems that have radiation levels that are safer. Ultimately, my research helps narrow down the most likely systems to host planets that should have stable atmospheres.

Sarah Peacock stands with her arms out with two posters about the Sun behind her.
Sarah Peacock research goal is to find habitable planets in other solar systems.
Courtesy of Sarah Peacock

Where does your data come from?

I predominately use data from the Hubble Space Telescope and from the now-retired spacecraft GALEX. My work itself is more theory-focused though: I create a modeled stellar spectrum across all wavelengths and use observations to validate my modeling.

What other areas of research are you involved in?

I am working with a team analyzing data from the James Webb Space Telescope to see if earthlike planets around M-type stars (a star that is cooler and smaller than the Sun) have atmospheres and, if so, what the composition of those atmospheres is. An exciting result from this work is that we may have detected water in the atmosphere of a rocky planet for the first time ever. However, we cannot yet distinguish with our current observations if that water comes from the planet or from spots on the star (starspots on this host star are cold enough for water to exist in gas form).

I am also helping manage a NASA Innovative Advance Concept (NIAC) study led by my mentor, Ken Carpenter, to work on the Artemis Enabled Stellar Imager (AeSI). If selected for further development, this imager would be an ultraviolet/optical interferometer located on the South Pole of the Moon. With this telescope, we would be able to map the surface of stars, image accretion disks, and image the centers of Active Galactic Nuclei.

As a relatively new employee to Goddard, what have been your first impressions?

Everyone who I have met, especially those in my lab, are incredibly friendly and welcoming. Starting during the pandemic, I was worried about feeling isolated, but instead, I was blown away by how many folks in my lab reached out to set up calls to introduce themselves and suggest opportunities for collaboration. It made me feel welcome.

Who is your mentor and what did your mentor advise you?

Ken Carpenter is my mentor. He encourages me to pursue my aspirations. He supports letting me chart my own path and being exposed to many different areas of research. I thank Ken for his support and encouragement and for including me on his projects.

Sarah Peacock hugs a white dog in the snow.
“Everyone who I have met, especially those in my lab, are incredibly friendly and welcoming.”
Courtesy of Sarah Peacock

What do you do for fun?

I am a new mom, so my usual hobbies are on pause! Right now, fun is taking care of my baby and introducing life experiences to him.

As a recently selected member of the Executive Committee for NASA’s Exoplanet Exploration Program Analysis Group (ExoPAG), what are your responsibilities?

The NASA ExoPAG is responsible for soliciting and coordinating scientific community input into the development and execution of NASA’s exoplanet exploration program. We solicit opinions and advice from any scientist who studies exoplanets. We are a bridge between NASA’s exoplanet scientists and NASA Headquarters in Washington.

What is a fun fact about yourself?

I got married the same day I defended my Ph.D. I had my defense in the morning and got married in the afternoon at the courthouse.

Who is your favorite author?

I love to read; I always have three books going. My favorite author is Louise Penny, who writes mysteries, but I read all genres. Right now, I am reading a biography about Marjorie Merriweather Post.

What is your favorite quote?

“The most that can be expected from any model is that it can supply a useful approximation to reality: All models are wrong; some models are useful.” —Box and Draper 1987

By Elizabeth M. Jarrell
NASA’s Goddard Space Flight Center, Greenbelt, Md.

A banner graphic with a group of people smiling and the text "Conversations with Goddard" on the right. The people represent many genders, ethnicities, and ages, and all pose in front of a soft blue background image of space and stars.

Conversations With Goddard is a collection of Q&A profiles highlighting the breadth and depth of NASA’s Goddard Space Flight Center’s talented and diverse workforce. The Conversations have been published twice a month on average since May 2011. Read past editions on Goddard’s “Our People” webpage.

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Last Updated
Dec 10, 2024

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      To view this video please enable JavaScript, and consider upgrading to a web browser that
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      Figure 5. Erica Tevere (at the operator’s station) and Ashish Goel (at the robot arm) setting up the OWLAT testbed for use. NASA/JPL – Caltech OceanWATERS
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      To view this video please enable JavaScript, and consider upgrading to a web browser that
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      Figure 7. Screenshot of OceanWATERS lander on a terrain modeled from the Atacama Desert. A scoop operation has just been completed. NASA/JPL – Caltech Because of Earth’s distance from the ocean worlds and the resulting communication lag, a planetary lander should be programmed with at least enough information to begin its mission. But there will be situation-specific challenges that will require onboard intelligence, such as deciding exactly where and how to collect samples, dealing with unexpected issues and hardware faults, and prioritizing operations based on remaining power. 
      Results
      All six of the research teams funded by the ARROW and COLDTech programs used OceanWATERS to develop ocean world lander autonomy technology and three of those teams also used OWLAT. The products of these efforts were published in technical papers, and resulted in development of software that may be used or adapted for actual ocean world lander missions in the future. The following table summarizes the ARROW and COLDTech efforts.
        Principal Investigator (PI) PI Institution Project Testbed Used Purpose of Project ARROW Projects Jonathan Bohren Honeybee Robotics Stochastic PLEXIL (SPLEXIL) OceanWATERS Extended PLEXIL with stochastic decision-making capabilities by employing reinforcement learning techniques. Pooyan Jamshidi University of South Carolina Resource Adaptive Software Purpose-Built for Extraordinary Robotic Research Yields (RASPBERRY SI) OceanWATERS & OWLAT Developed software algorithms and tools for fault root cause identification, causal debugging, causal optimization, and causal-induced verification. COLDTech Projects Eric Dixon Lockheed Martin Causal And Reinforcement Learning (CARL) for COLDTech OceanWATERS Integrated a model of JPL’s mission-ready Cold Operable Lunar Deployable Arm (COLDarm) into OceanWATERS and applied image analysis, causal reasoning, and machine learning models to identify and mitigate the root causes of faults, such as ice buildup on the arm’s end effector. Jay McMahon University of Colorado Robust Exploration with Autonomous Science On-board, Ranked Evaluation of Contingent Opportunities for Uninterrupted Remote Science Exploration (REASON-RECOURSE) OceanWATERS Applied automated planning with formal methods to maximize science return of the lander while minimizing communication with ground team on Earth. Melkior Ornik U Illinois, Urbana-Champaign aDaptive, ResIlient Learning-enabLed oceAn World AutonomY (DRILLAWAY) OceanWATERS & OWLAT Developed autonomous adaptation to novel terrains and selecting scooping actions based on the available image data and limited experience by transferring the scooping procedure learned from a low-fidelity testbed to the high-fidelity OWLAT testbed. Joel Burdick Caltech Robust, Explainable Autonomy for Scientific Icy Moon Operations (REASIMO) OceanWATERS & OWLAT Developed autonomous 1) detection and identification of off-nominal conditions and procedures for recovery from those conditions, and 2) sample site selection Acknowledgements: The portion of the research carried out at the Jet Propulsion Laboratory, California Institute of Technology was performed under a contract with the National Aeronautics and Space Administration (80NM0018D0004).  The portion of the research carried out by employees of KBR Wyle Services LLC at NASA Ames Research Center was performed under a contract with the National Aeronautics and Space Administration (80ARC020D0010). Both were funded by the Planetary Science Division ARROW and COLDTech programs.
      Project Leads: Hari Nayar (NASA Jet Propulsion Laboratory, California Institute of Technology), K. Michael Dalal (KBR, Inc. at NASA Ames Research Center)
      Sponsoring Organizations: NASA SMD PESTO
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