NASA’s Search for Water in the Universe

December 2017

Briefing date: December 7, 2017 (3:30pm)


Dr. Emma Marcucci (STScI)


  • Dr. Emma Marcucci (STScI)

  • Dr. Gary Melnick (Harvard CfA)

  • Dr. Rob Zellem (JPL – California Institute of Technology)

  • Dr. Avi Mandell (GSFC)

Slide presentation:

Transcript and audio recording:

Additional resources:

  • NASA Wavelength resources* (PDF file) 1.1 MB
    *Due to changes in the NASA Wavelength resource database, please use the attached resource PDF in lieu of URLs listed in slides. Original activity URLs should operate as normal.



On Earth, water is found across the planet and life could not survive without it. However, our understanding of how Earth came to have its water and the extent of water beyond Earth, and beyond the Solar System, remains open to debate. Water in the interstellar medium (ISM) was first detected in the 1960s, and with missions growing increasingly sensitive to resolving spectral features, we are now beginning to see how widespread water can be in the universe, including planets, moons, stars, star-forming clouds, and the ISM. Composed of hydrogen and oxygen, two abundant elements in the universe, water has been mapped throughout the ISM. This science briefing will focus on two locations that are in the forefront of the search for water studies. NASA missions are searching for water in the ISM where new stars and planets form, as well as in the atmospheres of exoplanets. Understanding the presence and distribution of water through astronomical objects helps us understand the evolution of the universe.

The search for water is one piece in our search for life, addressing one of NASA’s big Astrophysics questions—Are we alone?—and several NASA missions have made strides to understand the origin, abundance, and location of water across the universe.


Dr. Emma Marcucci is an Education and Outreach Scientist at the Space Telescope Science Institute. She received her Ph.D. in planetary geology from the University of Colorado at Boulder in 2013. As a Postdoctoral Fellow, she worked with satellite stereo images to derive topographic models of locations that lack good elevation information, such as locations in Alaska and on Mars and Mercury. Dr. Marcucci is now part of the Office of Public Outreach at STScI, sharing the science of Hubble and Webb with the general public and astrophysics content as a member of the Universe of Learning, an Astrophysics-based STEM learning and literacy program funded through NASA SMD.

Dr. Gary Melnick is a Senior Astronomer at the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts. As a graduate student at Cornell University, he built spectrometers designed to fly aboard specially modified NASA aircraft that flew into the stratosphere to observe cosmic emission unobservable from the ground. After receiving his Ph.D. in astronomy from Cornell in 1980, he joined the scientific staff at the Center for Astrophysics. Since 1980, he has been involved in four NASA and ESA space astronomy missions – the Space Shuttle-borne Infrared Telescope (IRT), the Submillimeter Wave Astronomy Satellite (SWAS), the Spitzer Space Telescope, and the Herschel Space Telescope. He served as the Principal Investigator (PI) for SWAS, the Deputy PI for Spitzer, and a Co-Investigator on the IRT and Herschel missions. SWAS, Spitzer, and Herschel all carried instruments that studied interstellar water. He is now involved in a NASA-funded mission study of a space telescope capable of mapping water ice throughout the Milky Way.

Dr. Rob Zellem is a Scientist at NASA’s Jet Propulsion Laboratory. He received his Ph.D. in planetary science at the University of Arizona’s Lunar and Planetary Laboratory in 2015. As a California Institute of Technology Postdoctoral Fellow, he simulated mission performances as a Science Team Member of both FINESSE and CASE, two proposed missions dedicated to studying exoplanet atmospheres. As a JPL Scientist, Dr. Zellem is leading the testing and implementation of the NESSI multi-object spectrograph for installation at Palomar Observatory. With NESSI and other ground- and space-based telescopes, Dr. Zellem uses the transit method to study the structure and composition of the atmospheres of other worlds.

Dr. Avi Mandell is a scientist in the Planetary Systems Laboratory at NASA Goddard; his research focuses on the characterization of extrasolar planets and the formation and evolution of planetary systems, with the specific goal of understanding factors that determine whether a planetary system can form habitable planets and what the characteristics of these planets will be.  He works on analyzing observations of transiting and directly imaged exoplanets and circumstellar disks, as well as modeling spectra of planetary atmospheres and the dynamical evolution of planetesimals during the formation of terrestrial planets.  He is the Director of the GSFC Sellers Exoplanet Environments Collaboration, and is the Project Scientist for the Coronagraph Integral Field Spectrograph for the WFIRST space telescope.