Jump to content

NASA: Some Icy Exoplanets May Have Habitable Oceans and Geysers


Recommended Posts

  • Publishers
Posted

5 min read

Preparations for Next Moonwalk Simulations Underway (and Underwater)

A NASA study expands the search for life beyond our solar system by indicating that 17 exoplanets (worlds outside our solar system) could have oceans of liquid water, an essential ingredient for life, beneath icy shells. Water from these oceans could occasionally erupt through the ice crust as geysers. The science team calculated the amount of geyser activity on these exoplanets, the first time these estimates have been made. They identified two exoplanets sufficiently close where signs of these eruptions could be observed with telescopes.

The search for life elsewhere in the Universe typically focuses on exoplanets that are in a star’s “habitable zone,” a distance where temperatures allow liquid water to persist on their surfaces. However, it’s possible for an exoplanet that’s too distant and cold to still have an ocean underneath an ice crust if it has enough internal heating. Such is the case in our solar system where Europa, a moon of Jupiter, and Enceladus, a moon of Saturn, have subsurface oceans because they are heated by tides from the gravitational pull of the host planet and neighboring moons.

cassini_enceladus_geysers
NASA’s Cassini spacecraft captured this image of Enceladus on Nov. 30, 2010. The shadow of the body of Enceladus on the lower portions of the jets is clearly visible.
NASA/JPL-Caltech/Space Science Institute

These subsurface oceans could harbor life if they have other necessities, such as an energy supply as well as elements and compounds used in biological molecules. On Earth, entire ecosystems thrive in complete darkness at the bottom of oceans near hydrothermal vents, which provide energy and nutrients.

“Our analyses predict that these 17 worlds may have ice-covered surfaces but receive enough internal heating from the decay of radioactive elements and tidal forces from their host stars to maintain internal oceans,” said Dr. Lynnae Quick of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “Thanks to the amount of internal heating they experience, all planets in our study could also exhibit cryovolcanic eruptions in the form of geyser-like plumes.” Quick is lead author of a paper on the research published on October 4 in the Astrophysical Journal.

The team considered conditions on 17 confirmed exoplanets that are roughly Earth-sized but less dense, suggesting that they could have substantial amounts of ice and water instead of denser rock. Although the planets’ exact compositions remain unknown, initial estimates of their surface temperatures from previous studies all indicate that they are much colder than Earth, suggesting that their surfaces could be covered in ice.

The study improved estimates of each exoplanet’s surface temperature by recalculating using the known surface brightness and other properties of Europa and Enceladus as models. The team also estimated the total internal heating in these exoplanets by using the shape of each exoplanet’s orbit to get the heat generated from tides and adding it to the heat expected from radioactive activity. Surface temperature and total heating estimates gave the ice layer thickness for each exoplanet since the oceans cool and freeze at the surface while being heated from the interior. Finally, they compared these figures to Europa’s and used estimated levels of geyser activity on Europa as a conservative baseline to estimate geyser activity on the exoplanets.

They predict that surface temperatures are colder than previous estimates by up to 60 degrees Fahrenheit (16 degrees Celsius). Estimated ice shell thickness ranged from about 190 feet (58 meters) for Proxima Centauri b and one mile (1.6 kilometers) for LHS 1140 b to 24 miles (38.6 kilometers) for MOA 2007 BLG 192Lb, compared to Europa’s estimated average of 18 miles (almost 29 kilometers). Estimated geyser activity went from just 17.6 pounds per second (about 8 kilograms/second) for Kepler 441b to 639,640 pounds/second (290,000 kilograms/second) for LHS 1140 b and 13.2 million pounds/second (six million kilograms/second) for Proxima Centauri b, compared to Europa at 4,400 pounds/second (2,000 kilograms/second).

“Since our models predict that oceans could be found relatively close to the surfaces of Proxima Centauri b and LHS 1140 b, and their rate of geyser activity could exceed Europa’s by hundreds to thousands of times, telescopes are most likely to detect geological activity on these planets,” said Quick, who is presenting this research December 12 at the American Geophysical Union meeting in San Francisco, California.

This activity could be seen when the exoplanet passes in front of its star. Certain colors of starlight could be dimmed or blocked by water vapor from the geysers. “Sporadic detections of water vapor in which the amount of water vapor detected varies with time, would suggest the presence of cryovolcanic eruptions,” said Quick. The water might contain other elements and compounds that could reveal if it can support life. Since elements and compounds absorb light at specific “signature” colors, analysis of the starlight would let scientists determine the geyser’s composition and evaluate the exoplanet’s habitability potential.

For planets like Proxima Centauri b that don’t cross their stars from our vantage point, geyser activity could be detected by powerful telescopes that are able to measure light that the exoplanet reflects while orbiting its star. Geysers would expel icy particles at the exoplanet’s surface which would cause the exoplanet to appear very bright and reflective.

The research was funded by NASA’s Habitable Worlds Program, the University of Washington’s Astrobiology Program, and the Virtual Planetary Laboratory, a member of the NASA Nexus for Exoplanet System Science coordination group.

Share

Details

Last Updated
Dec 13, 2023
Editor
William Steigerwald
Contact
Location
Goddard Space Flight Center

View the full article

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Similar Topics

    • By NASA
      6 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Sunlight reflects off the ocean surface near Norfolk, Virginia, in this 1991 space shuttle image, highlighting swirling patterns created by features such as internal waves, which are produced when the tide moves over underwater features. Data from the international SWOT mission is revealing the role of smaller-scale waves and eddies.NASA The international mission collects two-dimensional views of smaller waves and currents that are bringing into focus the ocean’s role in supporting life on Earth.
      Small things matter, at least when it comes to ocean features like waves and eddies. A recent NASA-led analysis using data from the SWOT (Surface Water and Ocean Topography) satellite found that ocean features as small as a mile across potentially have a larger impact on the movement of nutrients and heat in marine ecosystems than previously thought.
      Too small to see well with previous satellites but too large to see in their entirety with ship-based instruments, these relatively small ocean features fall into a category known as the submesoscale. The SWOT satellite, a joint effort between NASA and the French space agency CNES (Centre National d’Études Spatiales), can observe these features and is demonstrating just how important they are, driving much of the vertical transport of things like nutrients, carbon, energy, and heat within the ocean. They also influence the exchange of gases and energy between the ocean and atmosphere.
      “The role that submesoscale features play in ocean dynamics is what makes them important,” said Matthew Archer, an oceanographer at NASA’s Jet Propulsion Laboratory in Southern California. Some of these features are called out in the animation below, which was created using SWOT sea surface height data.

      This animation shows small ocean features — including internal waves and eddies — derived from SWOT observations in the Indian, Atlantic, and Pacific oceans, as well as the Mediterranean Sea. White and lighter blue represent higher ocean surface heights compared to darker blue areas. The purple colors shown in one location represent ocean current speeds.
      NASA’s Scientific Visualization Studio “Vertical currents move heat between the atmosphere and ocean, and in submesoscale eddies, can actually bring up heat from the deep ocean to the surface, warming the atmosphere,” added Archer, who is a coauthor on the submesoscale analysis published in April in the journal Nature. Vertical circulation can also bring up nutrients from the deep sea, supplying marine food webs in surface waters like a steady stream of food trucks supplying festivalgoers.
      “Not only can we see the surface of the ocean at 10 times the resolution of before, we can also infer how water and materials are moving at depth,” said Nadya Vinogradova Shiffer, SWOT program scientist at NASA Headquarters in Washington.
      Fundamental Force
      Researchers have known about these smaller eddies, or circular currents, and waves for decades. From space, Apollo astronauts first spotted sunlight glinting off small-scale eddies about 50 years ago. And through the years, satellites have captured images of submesoscale ocean features, providing limited information such as their presence and size. Ship-based sensors or instruments dropped into the ocean have yielded a more detailed view of submesoscale features, but only for relatively small areas of the ocean and for short periods of time.
      The SWOT satellite measures the height of water on nearly all of Earth’s surface, including the ocean and freshwater bodies, at least once every 21 days. The satellite gives researchers a multidimensional view of water levels, which they can use to calculate, for instance, the slope of a wave or eddy. This in turn yields information on the amount of pressure, or force, being applied to the water in the feature. From there, researchers can figure out how fast a current is moving, what’s driving it and —combined with other types of information — how much energy, heat, or nutrients those currents are transporting.  
      “Force is the fundamental quantity driving fluid motion,” said study coauthor Jinbo Wang, an oceanographer at Texas A&M University in College Station. Once that quantity is known, a researcher can better understand how the ocean interacts with the atmosphere, as well as how changes in one affect the other.
      Prime Numbers
      Not only was SWOT able to spot a submesoscale eddy in an offshoot of the Kuroshio Current — a major current in the western Pacific Ocean that flows past the southeast coast of Japan — but researchers were also able to estimate the speed of the vertical circulation within that eddy. When SWOT observed the feature, the vertical circulation was likely 20 to 45 feet (6 to 14 meters) per day.
      This is a comparatively small amount for vertical transport. However, the ability to make those calculations for eddies around the world, made possible by SWOT, will improve researchers’ understanding of how much energy, heat, and nutrients move between surface waters and the deep sea.
      Researchers can do similar calculations for such submesoscale features as an internal solitary wave — a wave driven by forces like the tide sloshing over an underwater plateau. The SWOT satellite spotted an internal wave in the Andaman Sea, located in the northeastern part of the Indian Ocean off Myanmar. Archer and colleagues calculated that the energy contained in that solitary wave was at least twice the amount of energy in a typical internal tide in that region.
      This kind of information from SWOT helps researchers refine their models of ocean circulation. A lot of ocean models were trained to show large features, like eddies hundreds of miles across, said Lee Fu, SWOT project scientist at JPL and a study coauthor. “Now they have to learn to model these smaller scale features. That’s what SWOT data is helping with.”
      Researchers have already started to incorporate SWOT ocean data into some models, including NASA’s ECCO (Estimating the Circulation and Climate of the Ocean). It may take some time until SWOT data is fully a part of models like ECCO. But once it is, the information will help researchers better understand how the ocean ecosystem will react to a changing world.
      More About SWOT
      The SWOT satellite was jointly developed by NASA and CNES, with contributions from the Canadian Space Agency (CSA) and the UK Space Agency. Managed for NASA by Caltech in Pasadena, California, JPL leads the U.S. component of the project. For the flight system payload, NASA provided the Ka-band radar interferometer (KaRIn) instrument, a GPS science receiver, a laser retroreflector, a two-beam microwave radiometer, and NASA instrument operations. The Doppler Orbitography and Radioposition Integrated by Satellite system, the dual frequency Poseidon altimeter (developed by Thales Alenia Space), the KaRIn radio-frequency subsystem (together with Thales Alenia Space and with support from the UK Space Agency), the satellite platform, and ground operations were provided by CNES. The KaRIn high-power transmitter assembly was provided by CSA.
      To learn more about SWOT, visit:
      https://swot.jpl.nasa.gov
      News Media Contacts
      Jane J. Lee / Andrew Wang
      Jet Propulsion Laboratory, Pasadena, Calif.
      626-491-1943 / 626-379-6874
      jane.j.lee@jpl.nasa.gov / andrew.wang@jpl.nasa.gov
      2025-070
      Share
      Details
      Last Updated May 15, 2025 Related Terms
      SWOT (Surface Water and Ocean Topography) Jet Propulsion Laboratory Oceanography Oceans Explore More
      6 min read NASA’s Magellan Mission Reveals Possible Tectonic Activity on Venus
      Article 23 hours ago 6 min read NASA Studies Reveal Hidden Secrets About Interiors of Moon, Vesta
      Article 1 day ago 5 min read NASA’s Europa Clipper Captures Mars in Infrared
      Article 3 days ago Keep Exploring Discover Related Topics
      Missions
      Humans in Space
      Climate Change
      Solar System
      View the full article
    • By NASA
      1 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      Will the Sun ever burn out?

      Well, the Sun, just like the stars we see at night, is a star. It’s a giant ball of super hot hydrogen.

      Gravity squeezes it in and it creates energy, which is what makes the Sun shine. Eventually, it will use up all of that hydrogen. But in the process, it’s creating helium. So it will then use the helium. And it will continue to use larger and larger elements until it can’t do this anymore.

      And when that happens, it will start to expand into a red giant about the size of the inner planets. Then it will shrink back down into a very strange star called a white dwarf — super hot, but not very bright and about the size of the Earth.

      But our Sun has a pretty long lifetime. It’s halfway through its 10-billion-year lifetime.

      So the Sun will never really burn out, but it will change and be a very, very different dim kind of star when it reaches the end of its normal life.

      [END VIDEO TRANSCRIPT]

      Full Episode List

      Full YouTube Playlist
      Share
      Details
      Last Updated May 15, 2025 Related Terms
      Science Mission Directorate Heliophysics Heliophysics Division The Solar System The Sun The Sun & Solar Physics Explore More
      4 min read Eclipses, Auroras, and the Spark of Becoming: NASA Inspires Future Scientists
      In the heart of Alaska’s winter, where the night sky stretches endlessly and the aurora…
      Article 16 hours ago 6 min read NASA Observes First Visible-light Auroras at Mars
      On March 15, 2024, near the peak of the current solar cycle, the Sun produced…
      Article 19 hours ago 6 min read NASA’s Magellan Mission Reveals Possible Tectonic Activity on Venus
      Article 19 hours ago Keep Exploring Discover Related Topics
      Missions
      Humans in Space
      Climate Change
      Solar System
      View the full article
    • By Amazing Space
      LIVE NOW: 15th May Sun Close up Views/ Backyard Astronomy with Lunt Telescope
    • By Amazing Space
      LIVE NOW: 15th May Sun Close up Views/ Backyard Astronomy with Lunt Telescope
    • By NASA
      6 min read
      Preparations for Next Moonwalk Simulations Underway (and Underwater)
      New research suggests vast surface features on Venus called coronae continue to be shaped by tectonic processes. Observations of these features from NASA’s Magellan mission include, clockwise from top left, Artemis Corona, Quetzalpetlatl Corona, Bahet Corona, and Aine Corona.NASA/JPL-Caltech Using archival data from the mission, launched in 1989, researchers have uncovered new evidence that tectonic activity may be deforming the planet’s surface.
      Vast, quasi-circular features on Venus’ surface may reveal that the planet has ongoing tectonics, according to new research based on data gathered more than 30 years ago by NASA’s Magellan mission. On Earth, the planet’s surface is continually renewed by the constant shifting and recycling of massive sections of crust, called tectonic plates, that float atop a viscous interior. Venus doesn’t have tectonic plates, but its surface is still being deformed by molten material from below.
      Seeking to better understand the underlying processes driving these deformations, the researchers studied a type of feature called a corona. Ranging in size from dozens to hundreds of miles across, a corona is most often thought to be the location where a plume of hot, buoyant material from the planet’s mantle rises, pushing against the lithosphere above. (The lithosphere includes the planet’s crust and the uppermost part of its mantle.) These structures are usually oval, with a concentric fracture system surrounding them. Hundreds of coronae are known to exist on Venus.
      Published in the journal Science Advances, the new study details newly discovered signs of activity at or beneath the surface shaping many of Venus’ coronae, features that may also provide a unique window into Earth’s past. The researchers found the evidence of this tectonic activity within data from NASA’s Magellan mission, which orbited Venus in the 1990s and gathered the most detailed gravity and topography data on the planet currently available.
      “Coronae are not found on Earth today; however, they may have existed when our planet was young and before plate tectonics had been established,” said the study’s lead author, Gael Cascioli, assistant research scientist at the University of Maryland, Baltimore County, and NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “By combining gravity and topography data, this research has provided a new and important insight into the possible subsurface processes currently shaping the surface of Venus.”
      This artist’s concept of the large Quetzalpetlatl Corona located in Venus’ southern hemisphere depicts active volcanism and a subduction zone, where the foreground crust plunges into the planet’s interior. A new study suggests coronae are the locations of several types of tectonic activity.NASA/JPL-Caltech/Peter Rubin As members of NASA’s forthcoming VERITAS (Venus Emissivity, Radio science, InSAR, Topography, and Spectroscopy) mission, Cascioli and his team are particularly interested in the high-resolution gravity data the spacecraft will provide. Study coauthor Erwan Mazarico, also at Goddard, will co-lead the VERITAS gravity experiment when the mission launches no earlier than 2031.
      Mystery Coronae
      Managed by NASA’s Jet Propulsion Laboratory in Southern California, Magellan used its radar system to see through Venus’ thick atmosphere and map the topography of its mountains and plains. Of the geological features the spacecraft mapped, coronae were perhaps the most enigmatic: It wasn’t clear how they formed. In the years since, scientists have found many coronae in locations where the planet’s lithosphere is thin and heat flow is high.
      “Coronae are abundant on Venus. They are very large features, and people have proposed different theories over the years as to how they formed,” said coauthor Anna Gülcher, Earth and planetary scientist at the University of Bern in Switzerland. “The most exciting thing for our study is that we can now say there are most likely various and ongoing active processes driving their formation. We believe these same processes may have occurred early in Earth’s history.”
      The researchers developed sophisticated 3D geodynamic models that demonstrate various formation scenarios for plume-induced coronae and compared them with the combined gravity and topography data from Magellan. The gravity data proved crucial in helping the researchers detect less dense, hot, and buoyant plumes under the surface — information that couldn’t be discerned from topography data alone. Of the 75 coronae studied, 52 appear to have buoyant mantle material beneath them that is likely driving tectonic processes.
      One key process is subduction: On Earth, it happens when the edge of one tectonic plate is driven beneath the adjacent plate. Friction between the plates can generate earthquakes, and as the old rocky material dives into the hot mantle, the rock melts and is recycled back to the surface via volcanic vents.
      These illustrations depict various types of tectonic activity thought to persist beneath Venus’ coronae. Lithospheric dripping and subduction are shown at top; below are and two scenarios where hot plume material rises and pushes against the lithosphere, potentially driving volcanism above it.Anna Gülcher, CC BY-NC On Venus, a different kind of subduction is thought to occur around the perimeter of some coronae. In this scenario, as a buoyant plume of hot rock in the mantle pushes upward into the lithosphere, surface material rises and spreads outward, colliding with surrounding surface material and pushing that material downward into the mantle.
      Another tectonic process known as lithospheric dripping could also be present, where dense accumulations of comparatively cool material sink from the lithosphere into the hot mantle. The researchers also identify several places where a third process may be taking place: A plume of molten rock beneath a thicker part of the lithosphere potentially drives volcanism above it.
      Deciphering Venus
      This work marks the latest instance of scientists returning to Magellan data to find that Venus exhibits geologic processes that are more Earth-like than originally thought. Recently, researchers were able to spot erupting volcanoes, including vast lava flows that vented from Maat Mons, Sif Mons, and Eistla Regio in radar images from the orbiter.
      While those images provided direct evidence of volcanic action, the authors of the new study will need sharper resolution to draw a complete picture about the tectonic processes driving corona formation. “The VERITAS gravity maps of Venus will boost the resolution by at least a factor of two to four, depending on location — a level of detail that could revolutionize our understanding of Venus’ geology and implications for early Earth,” said study coauthor Suzanne Smrekar, a planetary scientist at JPL and principal investigator for VERITAS.
      Managed by JPL, VERITAS will use a synthetic aperture radar to create 3D global maps and a near-infrared spectrometer to figure out what the surface of Venus is made of.  Using its radio tracking system, the spacecraft will also measure the planet’s gravitational field to determine the structure of Venus’ interior. All of these instruments will help pinpoint areas of activity on the surface.
      For more information about NASA’s VERITAS mission, visit:
      https://science.nasa.gov/mission/veritas/
      News Media Contacts
      Ian J. O’Neill
      Jet Propulsion Laboratory, Pasadena, Calif.
      818-354-2649
      ian.j.oneill@jpl.nasa.gov
      Karen Fox / Molly Wasser
      NASA Headquarters, Washington
      202-358-1600
      karen.c.fox@nasa.gov / molly.l.wasser@nasa.gov
      2025-068
      Share
      Details
      Last Updated May 14, 2025 Related Terms
      Magellan Jet Propulsion Laboratory Planetary Science Venus VERITAS (Venus Emissivity, Radio Science, InSAR, Topography & Spectroscopy) Explore More
      6 min read NASA Studies Reveal Hidden Secrets About Interiors of Moon, Vesta
      Article 3 hours ago 5 min read NASA’s Europa Clipper Captures Mars in Infrared
      Article 2 days ago 3 min read NASA Study Reveals Venus Crust Surprise
      New details about the crust on Venus include some surprises about the geology of Earth’s…
      Article 5 days ago Keep Exploring Discover Related Topics
      Missions
      Humans in Space
      Climate Change
      Solar System
      View the full article
  • Check out these Videos

×
×
  • Create New...