Prime targets include moons that harbor hidden oceans beneath a shell of ice: Europa, Enceladus, and Titan. A host of other bodies in the outer Solar System are inferred by a single type of observation or by theoretical modeling to have subsurface oceans.
The US House Appropriations Committee approved the bill on May 20, 2015, and directed NASA to create the Ocean Worlds Exploration Program.[2] The "Roadmaps to Ocean Worlds" (ROW) was started in 2016,[3][4] and was presented in January 2019.[5] The formal program is being implemented within the agency by supporting the Europa Clipper orbiter mission to Europa,[3][6] and the Dragonfly mission to Titan. The program is also supporting concept studies for a proposed Europa Lander,[7] and concepts to explore the moon Triton.[8][5]Amanda Hendrix and Terry A. Hurford are the co-leads of the NASA Roadmaps to Oceans World Group.[5][9]
^Cite error: The named reference Phys2017 was invoked but never defined (see the help page).
^ abcThe NASA Roadmap to Ocean Worlds. Amanda R. Hendrix, Terry A. Hurford, Laura M. Barge, Michael T. Bland, Jeff S. Bowman, William Brinckerhoff, Bonnie J. Buratti, Morgan L. Cable, Julie Castillo-Rogez, Geoffrey C. Collins, etal. Astrobiology, Vol. 19, No. 1. doi:10.1089/ast.2018.1955
^"NASA's FY2016 Budget Request"(PDF). Space Policy Online. 27 May 2015. Archived from the original(PDF) on 2020-07-31. Retrieved 2017-09-30. In fact, the report accompanying the bill directs NASA to create an "Ocean Worlds Exploration Program" of which the Europa mission is part.
^Europa Lander. Home Page at the Jet Propulsion Laboratory (JPL) NASA. Accessed on 22 September 2019.