7.3% 0.1% 0.03% 0.02%
1 2 6 7 8 H He C N O Hydrogen Helium Carbon Nitrogen Oxygen Credit: NASA Sources: Wong et al. (2004). Icarus, Vol. 171. von Zahn et al. (1998). Journal of Geophysical Research, Vol. 103. JUPITER DR.Space Science JULIANNE Institute (SSI) MOSES Jupiter’s chemical composition is vastly different from that of Earth. Being composed largely of hydrogen and helium, with much smaller amounts of heavier elements, Jupiter has more in common with the Sun than with the terrestrial planets in our solar system. However, scientists do not know the precise composition of Jupiter’s atmosphere or interior. Clouds and the Dr. Julianne Moses is a senior research scattering of light by gases prevent us from peering deep into the atmosphere scientist at the Space Science Institute with remote-sensing instruments. In 1995, a probe released from NASA’s (SSI) at their Seabrook, Texas, branch. Galileo spacecraft fell through Jupiter’s atmosphere, providing excellent She investigates physical and chemical measurements of the amount of hydrogen, helium, and several heavier processes in planetary and satellite elements during its descent. atmospheres, with a particular emphasis However, the probe entered on giant-planet and exoplanet chemistry. Jupiter’s atmosphere in a She studies how planetary atmospheric meteorologically strange composition is altered by the chemistry region and may not have that is initiated when atmospheric gases penetrated deep enough absorb ultraviolet light or interact with before breaking up to sample high-energy charged particles. Her recent the full amount of water research projects include investigations into thought to be below the how interplanetary dust particles and comets affect giant-planet atmospheric cloud base. Therefore, the composition, how the abundance of hydrocarbon and oxygen molecules on oxygen abundance reported Uranus and Neptune vary with season, and how disequilibrium chemistry on the front is considered affects the composition of young extrasolar planets. The models she develops to be a lower limit. Because are typically compared with spectroscopic observations from groundbased the relative abundance This image of dramatic cloud formations in Jupiter’s telescopes and spacecraft such as Cassini and the Spitzer space telescope, of elements heavier than northern hemisphere was captured by JunoCam onboard or are used to help plan future observations from the James Webb Space the Juno spacecraft. Credit: NASA/JPL-Caltech/SwRI/ Telescope. Her research may aid in understanding the formation and evolution hydrogen and helium within MSSS/Kevin M. Gill Jupiter provides important of planetary systems. Moses is awed by the recent discoveries of extrasolar clues to the various processes involved with its formation and evolution, a planets and their apparent amazing diversity. Aside from conducting research, major goal of the current Juno mission is to better constrain the elemental she has been a director of SSI’s Center for Extrasolar Planetary Systems, a composition of Jupiter’s atmosphere, including the deep oxygen abundance. director of a summer undergraduate intern program, an editor for a planetary Scientists are eagerly awaiting the full results from Juno. science journal, and an advisor for high school and undergraduate students.
Founded at the height of the Apollo program in 1968, the Lunar and Planetary Institute (LPI) is an The year 2019 marks the 150th anniversary of Dmitri Mendeleev’s development of the Periodic intellectual leader in lunar and planetary science. LPI’s mission is to advance understanding of the System and has been proclaimed the “International Year of the Periodic Table of Chemical solar system by providing exceptional science, service, and inspiration to the world. The research Elements” (IYPT2019). carried out at LPI supports NASA’s efforts to explore the solar system. www.iypt2019.org www.lpi.usra.edu