Earth as seen from Apollo 11 as it coasted to the Moon.

Solar System Exploration

During June, NASA, NOAA, and people around the world are celebrating Earth’s Ocean as part of National Ocean Month. NASA has been observing Earth's ocean from space for more than 20 years. Now, NASA is launching missions to explore other ocean worlds.

Why Oceans Matter

The story of oceans is the story of life.

Life as we know it requires three ingredients: energy, organic molecules, and liquid water. Our search for life beyond Earth is, in part, a search for planets and moons that harbor substantial liquid water. We call these places “ocean worlds,” and we’re learning that they could be ubiquitous in the galaxy. 

As we learn more about our own ocean, we better understand these worlds beyond Earth. NASA has missions planned to explore two ocean moons.

NASA Missions to Ocean Worlds

Europa Clipper

NASA's Europa Clipper is launching Oct. 10, 2024, on the first mission to conduct a detailed science investigation of Jupiter's moon Europa. Scientists predict Europa has a salty ocean beneath its icy crust that could hold the building blocks necessary to sustain life.

Learn About Europa Clipper
Illustration of the surface of Europa - shown as icy blue - with Jupiter behind it, and the Europa Clipper spacecraft in front of Jupiter.
An illustration of NASA's Europa Clipper spacecraft above the surface of Europa and in front of Jupiter.
NASA/JPL-Caltech

Dragonfly

Making multiple flights, the Dragonfly rotorcraft will explore a variety of locations on Saturn's moon Titan. Titan’s abundant complex carbon-rich chemistry, interior ocean, and past presence of liquid water on the surface make it an ideal destination to study prebiotic chemical processes and the potential habitability of an extraterrestrial environment.

Learn About Dragonfly
A shiny spacecraft sits on a red-brown sandy surface. Sand dunes are shown rising high in the distance.
An artist's concept of NASA's Dragonfly rotorcraft-lander on Titan.
NASA

Featured Ocean Worlds

A view of Europa showing most of one side of the moon. The moon is gray with reddish bands running across it.

Europa

Europa is the fourth largest of Jupiter’s 95 moons. Scientists believe it has a saltwater ocean beneath its icy shell, holding twice as much water as Earth's global ocean.

Hazy, yellowish Titan against the darkness of space

Titan

Saturn’s largest moon Titan has liquids like methane and ethane flowing on its surface. Beneath Titan’s thick crust of water ice is more liquid—an ocean primarily of water.

Brightly lit moon of Saturn

Enceladus

Saturn’s moon Enceladus is a small, icy world that has geyser-like jets spewing water vapor and ice particles into space.

A half-globe view of Jupiter's moon, Ganymede. The moon is gray with a big crater on the right side of the image. The moon also has streaks of lighter and darker materials.

Ganymede

Jupiter’s icy moon Ganymede is the largest moon in our solar system. There’s strong evidence Ganymede has an underground saltwater ocean that may hold more water than all the water on Earth's surface. 

Jupiter's moon Callisto appears in space, pockmarked by many bright craters in its dark, brown surface.

Callisto

Once thought to be a dead world, data gathered by NASA's Galileo spacecraft indicates Callisto may have a salty ocean beneath its icy surface.

Ocean Month Articles

A portion of Earth and its global ocean as seen from the International Space Station. A piece of the station is visible in this image. The Sun is reflecting off something off to the left side.

National Ocean Month: Astrobiology and Earth's Oceans

Earth's Gakkel Ridge and the Exploration of Icy Worlds

Part of research ship can be seen in icy waters.

Exploring Enceladus in the Arctic

A mostly red submersible research vessel hangs over the ocean.

Exploring the Aurora Hydrothermal Vent Field

Ocean Worlds Research

An artist's concept showing ocean worlds against a blue background with comets and stars, and part of spacecraft's solar panels showing.

Oceans Across the Solar System

A graphic showing hydrothermal activity in Enceladus' core

Identifying Hydrothermal Activity on Icy Ocean Worlds

Blue, green and white-capped waves.

Reactions for Life at the Ocean Surface

Featured Story

Ocean Worlds: Water in the Solar System and Beyond

The story of oceans is the story of life. Life as we know it requires three ingredients: energy, organic molecules,…

Read the Story
An illustration shows the curving horizon of an icy moon's surface, from which several jets of ice particles and water vapor spray, catching the Sun's light. A robotic spacecraft, Cassini, is visible as a small shape in the distance, headed for the icy plumes.

Ocean World Videos

A colorful slate promoting a video for the Ask an Astrobiologist video series.

How to Detect Life on Ocean Worlds and Become a Viral Sensation with Dr. Lena Vincent

A colorful slate promoting a video for the Ask an Astrobiologist video series.

The Secret World of Hydrothermal Systems with Dr. Geoff Wheat

A colorful slate promoting a video for the Ask an Astrobiologist video series.

Deep-sea Diving and Searching for Life on Ocean Worlds with Dr. Kevin Hand

10 THINGS about our solar system

This is an updated montage of planetary images taken by spacecraft managed by NASA’s Jet Propulsion Laboratory in Pasadena, CA. Included are from top to bottom images of Mercury, Venus, Earth and Moon, Mars, Jupiter, Saturn, Uranus and Neptune.

Our solar system has eight planets, and five dwarf planets.

Gray-colored asteroid Bennu is shaped like a spinning top.

More than 1.3 million asteroids, and about 3,900 comets are in our solar system.

Our solar system has more than 200 moons.

A swirling Milky Way Galaxy, with our Sun seen on the outskirts.

Our solar system is in one of the Milky Way galaxy’s four spiral arms.

Sun and planets in solar system

Our solar system takes about 230 million years to orbit the galactic center.

Spitzer Milky Way 1600px

The Milky Way is a spiral galaxy.

The blue limb of Earth as viewed from the space station.

Our solar system has many worlds with many types of atmospheres.

The four giant planets – and at least one asteroid – have rings.

Man in the moon with American flag

More than 300 robotic spacecraft have left Earth's orbit, and 24 U.S. astronauts have traveled to the Moon.

Earth blue marble photo

So far, Earth is the only place we've found life in our solar system.

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