Our exploration of the outer Solar System has revealed a host of icy moons, many with surface features that suggest a complex geology. In some cases, these featuresβmost notably the geysers of Enceladusβhint at the presence of oceans beneath the icy surfaces. These oceans have been ascribed to gravitational interactions that cause flexing and friction within the moon, creating enough heat to melt the bodyβs interior.
Something that has received a bit less attention is that some of these orbital interactions are temporary or cyclical. The orbits of any body are not always regular and often have long-term cycles. Thatβs also true for the other moons that provide the gravitational stress. As a result, the internal oceans may actually come and go, as the interiors of the moons melt and refreeze.
A new study, released today by Nature Astronomy, looks at one of the consequences of the difference in density between liquid water and ice (about 10 percent): the potential for the moonβs interior to shrink as it melts, leaving an area of low pressure immediately below its icy shell. If the moon is small enough, this study suggests, that could cause the surface of the ocean to boil.
In this artistβs concept, the ocean-observing satellite Sentinel-6B orbits Earth with its deployable solar panels extended.
Credit: NASA/JPL-Caltech
NASA will provide live coverage of prelaunch and launch activities for Sentinel-6B, an international mission delivering critical sea level and ocean data to protect coastal infrastructure, improve weather forecasting, and support commercial activities at sea.
Launch is targeted at 12:21 a.m. EST, Monday, Nov. 17 (9:21 p.m. PST, Sunday, Nov. 16) aboard a SpaceX Falcon 9 rocket from Space Launch Complex 4 East at Vandenberg Space Force Base in California.
Watch coverage beginning at 11:30 p.m. EST (8:30 p.m. PST) on NASA+, Amazon Prime, and more. Learn how to watch NASA content through a variety of platforms, including social media.
The Sentinel-6B mission continues a decades-long effort to monitor global sea level and ocean conditions using precise radar measurements from space. Since the early 1990s, satellites launched by NASA and domestic and international partners have collected precise sea level data. The launch of Sentinel-6B will extend this dataset out to nearly four decades.
NASAβs mission coverage is as follows (all times Eastern and subject to change based on real-time operations):
Saturday, Nov. 15
4 p.m. β NASA Prelaunch Teleconference on International Ocean Tracking Mission
Karen St. Germain, director, Earth Science Division, NASA Headquarters in Washington
Pierrik Veuilleumier, Sentinel-6B project manager, ESA (European Space Agency)
Parag Vaze, Sentinel-6B project manager, NASAβs Jet Propulsion Laboratory in Pasadena, California
Tim Dunn, senior launch director, Launch Services Program, NASAβs Kennedy Space Center in Florida
Julianna Scheiman, director, NASA Science Missions, SpaceX
1st Lt. William Harbin, launch weather officer, U.S. Air Force
11:30 p.m. β Launch coverage begins on NASA+, Amazon Prime, and more.
Audio-only coverage
Audio-only of the launch coverage will be carried on the NASA βVβ circuits, which may be accessed by dialing 321-867-1220 or -1240. On launch day, βmission audioβ countdown activities without NASA+ launch commentary will be carried at 321-867-7135.
NASA website launch coverage
Launch day coverage of the mission will be available on the agencyβs website. Coverage will include links to live streaming and blog updates beginning no earlier than 11 p.m. EST, Nov. 16, as the countdown milestones occur. Streaming video and photos of the launch will be accessible on demand shortly after liftoff. Follow countdown coverage on NASAβs Sentinel-6/Jason-CS blog.
For questions about countdown coverage, contact the NASA Kennedy newsroom at: 321-867-2468.
Attend launch virtually
Members of the public can register to attend this launch virtually. NASAβs virtual guest program for this mission includes curated launch resources, notifications about related opportunities or changes, and a stamp for the NASA virtual guest passport following launch.
Watch, engage on social media
Let people know youβre watching the mission on X, Facebook, and Instagram by following and tagging these accounts:
Sentinel-6B is the second of twin satellites in the Copernicus Sentinel-6/Jason-CS (Continuity of Service) mission, a collaboration among NASA, ESA, EUMETSAT (European Organisation for the Exploitation of Meteorological Satellites), and the National Oceanic and Atmospheric Administration (NOAA). The first satellite in the mission, Sentinel-6 Michael Freilich, launched in November 2020. The European Commission contributed funding support, while Franceβs space agency CNES (Centre National dβΓtudes Spatiales) provided technical expertise. The mission also marks the first international involvement in Copernicus, the European Unionβs Earth Observation Programme.