artist's illustration of Europa's surface

Ocean Worlds Resources

Feature | August 17, 2020

Introduction

This page showcases our resources for those interested in learning more about ocean worlds. It includes activities that can be done at home as well as videos, animations, stories, and articles.

On this page:

Highlights

Videos & Animations

  • Life as we know it requires three ingredients: energy, organic molecules, and liquid water. Our search for life beyond Earth is a search for planets, dwarf planets, and moons that harbor substantial liquid water. Learn more about these places we call “ocean worlds.”

EUROPA


  • Scientists think there is an ocean within Jupiter’s moon Europa. Discover why scientists are so excited about the potential of this ice-covered world to answer one of humanity’s most profound questions – is there life beyond Earth?

NASA’s Scientific Visualization Studio (SVS)

Night Sky Network (NSN) Webinar

TITAN


NASA’s Scientific Visualization Studio (SVS)

  • Dragonfly is a NASA mission to explore the chemistry and habitability of Saturn’s largest moon, Titan. Dragonfly will send an autonomously-operated rotorcraft to visit dozens of sites on Titan, investigating the moon’s surface and shallow subsurface for organic molecules and possible biosignatures. Explore these animations to learn more about Dragonfly and its various instruments.

  • Discover how Dragonfly’s suite of science instruments will investigate the chemistry and habitability of Titan.

  • Learn about how Saturn’s moon, Titan, is expanding our understanding of the chemical complexity of the solar system and the potential for life in the universe.

Johns Hopkins University Applied Physics Laboratory

  • Search this gallery for videos, animations, images, and illustrations of the Dragonfly mission to Titan.

Activities

  • Exploring the Universe: Ice Orbs

    Learn how NASA planetary scientists are probing ocean worlds in the outer solar system, searching for evidence of liquid water and possible signs of life beneath the icy surface. Put what you learn into practice by investigating a frozen sphere using various tools to learn about objects hidden inside.

    This activity can be adapted to include other tools and probes, whatever you may already have on-hand.

    Note: This activity is also available in Spanish.

  • Planetary (Egg) Wobble and Newton’s First Law

    By observing the motions of spinning eggs, you will learn how to determine which are raw and which are hard-boiled. You can then use what you learn to discover how scientists conclude whether the center of a planetary body is liquid or solid.

    In this activity, the raw egg can be compared to an ocean world while the hard-boiled egg can be compared to a solid planetary body.

    Note: This activity was made for NASA’s InSight mission to Mars but can be adapted to discuss ocean worlds.

Stories

1. Ocean World Diversity (no two are the same!)

Triton's surface

Enceladus

Tiny moon (313.3 miles or 504.2 kilometers), about as wide as Arizona!

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Layers: Ice crust, then global ocean, then rocky core

Scientists predict that a regional reservoir about 6 miles (10 kilometers) deep lies under a shell of ice 20 to 25 miles (30 to 40 kilometers) thick at Enceladus’s south pole.

This underground ocean is thought to feed the moon’s impressive jets, which spray from deep fissures (called “tiger stripes”) in the moon’s surface.

One of Saturn’s moons

Titan

Titan is believed to have a salty subsurface ocean – as salty as the Dead Sea on Earth – beginning about 30 miles (50 kilometers) below its ice shell.

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It is possible that Titan’s ocean is thin and sandwiched between layers of ice or that it is thick and extends all the way down to the moon’s rocky interior.

Titan is expanding our understanding of the chemical complexity of the solar system and the potential for life in the universe. The Dragonfly mission (a rover-size drone-like vehicle) will take advantage of the moon’s environment (thick atmosphere and low surface gravity) to sample materials and determine surface composition in dozens of locations across the icy world.

One of Saturn’s moons

Europa

NASA’s Europa Clipper mission will conduct a detailed survey of Jupiter’s moon, Europa, to determine whether the icy moon could harbor conditions suitable for life.

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Scientists strongly suspect that a subsurface salty ocean lies beneath Europa’s icy crust. Tidal heating from its parent planet maintains this ocean’s liquid state and could also create partially melted pockets, or lakes, throughout the moon’s outer shell. Europa also has huge geysers, and scientists have detected water vapor erupting from these plumes above the moon’s surface.

Ganymede

Ganymede is the largest moon in our solar system (similar in size to the planet Mercury) and is the only moon with its own magnetic field.

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Possible layers: ice crust, salty liquid ocean, another ice layer, liquid ocean, another ice layer (could be similar to Titan’s potentially sandwiched ocean)

One of Jupiter’s moons

Triton

Triton, a moon of Neptune, was the first place in the solar system where scientists found cryovolcanoes, ice volcanoes which spew out plumes of water-ice and other frozen molecules rather than molten rock.

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Active geysers on Triton spew nitrogen gas, making this moon one of the known active worlds in the outer solar system.

A subsurface ocean at Triton is considered possible but is unconfirmed.

Volcanic features and fractures mark its cold, icy surface, likely results of past tidal heating.

2. Ocean Worlds and Astrobiology

Saturn’s moon Encedalus sends out regular plumes of water vapor — as seen here as imaged by the Cassini spacecraft — that are known to contain complex organic molecules.

Ocean Worlds May Harbor Life!

Did you know that there are other objects in our solar system (besides Earth!) that are considered “ocean worlds” and that these worlds have the potential to harbor life?

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Jupiter’s moon, Europa, is just one of these worlds, and the Europa Clipper mission is preparing to uncover its mysteries, including learning more about the moon’s water vapor plumes.

Saturn’s moon, Titan, is expanding our understanding of the chemical complexity of the solar system and the potential for life in the universe with its unique chemical composition.

Where We Look

Key places to find potential life is at two different boundaries/layers: an ice-liquid ocean boundary and/or a rock-liquid ocean boundary.

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A water-rock interface can be found at both Europa and Enceladus.

The Dragonfly mission’s target is an impact crater because such a site is more likely to have mixing of organics with liquid water at the surface (i.e. exchange of material between the surface and the interior).

Cryovolcanism (like on Neptune’s moon, Triton) is another way that this mixing of surface materials with the interior can occur.

Planetary Ingredients for Life

Water, essential elements, chemical energy, stability

Astrobiology Resources

3. Are Planets with Oceans Common in the Galaxy? It’s Likely, NASA Scientists Find

Illustration of Enceladus plumes

Exoplanets, or planets beyond our solar system, might resemble some of the watery moons around Jupiter and Saturn.

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Though some of these moons don’t have atmospheres and are covered in ice, they are still among the top targets in NASA’s search for life beyond Earth. Saturn’s moon Enceladus and Jupiter’s moon Europa, which scientists classify as “ocean worlds,” are good examples.

The more scientists can learn about Europa and other potentially habitable moons of our solar system, the better they’ll be able to understand similar worlds around other stars — which may be plentiful. Upcoming missions (such as the Europa Clipper mission to Jupiter’s moon Europa and the Dragonfly mission to Saturn’s moon Titan) will give scientists a chance to see whether ocean moons in our solar system could support life. If scientists find chemical signatures of life at these moons, they can then try to look for similar signs at interstellar distances.

Other Resources

  • Enceladus surface features
    NASA’s Solar System Treks

    The Solar System Treks are online, browser-based portals that allow you to visualize, explore, and analyze the surfaces of other worlds using real data returned from a growing fleet of spacecraft. You can view the worlds through the eyes of many different instruments, pilot real-time 3D flyovers above mountains and into craters, and conduct measurements of surface features.

  • Learn about ocean worlds and their potential for harboring life in this handout.

  • Ocean Worlds Poster thumb
    Ocean Worlds Poster

    Earth isn’t the only ocean world in our solar system. Use this poster to discover the oceans that could exist in diverse forms on moons and dwarf planets.

    Horizontal version

    • Note: A Spanish version of this poster is available here.

    Vertical version

    • Note: A Spanish version of this poster is available here.
  • Flip through this slideshow to see what we know about ocean worlds in our solar system.