Exploring the nations paving the way for the future of AI
Scientists were first alerted to this hidden ocean in 2015 after NASA's Cassini mission observed geyser-like jets spewing water vapor and ice particles into space from the moon's south polar region.
The plumes the Cassini spacecraft encountered were pushed up by hydrothermal vents on the seafloor. Intriguingly, the mission confirmed Enceladus has the right chemical ingredients for microbial life in its ocean.
In 2018, NASA identified a large amount of water in the atmosphere of a giant exoplanet known as WASP-39b. Scientists used the Hubble and Spitzer space telescopes to find the "fingerprints" of water located around WASP-39b, which is 700 light-years from Earth. An exoplanet, by the way, is a planet that orbits a star outside the solar system.
The dwarf planet known as Ceres sits in the middle main asteroid belt between the orbits of Mars and Jupiter.
If their hypothesis is correct, Ceres likely has a solid core and a mantle made of water ice. If confirmed, this small planetary mass has more water than Earth does. The diagram illustrates a possible internal structure of Ceres.
NASA's James Webb Space Telescope made a further discovery when instruments revealed details of how Enceladus is feeding a water supply to the entire system of the ringed planet.
One astonishing discovery made in 2022 shocked and delighted astrophysicists and astronomers alike. Using two different telescopes, one in Hawaii and one in California, the scientists identified the largest and oldest mass of water ever detected in the universe—a gigantic, 12-billion-year-old cloud harboring 140 trillion times more water than all of Earth's oceans combined.
In 2015, the dark, narrow streaks on the slopes of Hale Crater observed by the Mars Reconnaissance Orbiter (MRO) were inferred to be formed by seasonal flow of water on the surface of Mars. An excited NASA later confirmed evidence that liquid water does indeed flow on the Martian surface.
And the planet's gigantic Valles Marineris can be compared to the Earth's Grand Canyon but is as long as the United States is wide. A study released by the University of Colorado and NASA on December 5, 2002, theorized that water, which might have carved canyons like Valles Marineris, came from short cataclysmic events caused by asteroids slamming into the Martian surface and melting ice under ground.
Further analysis undertaken by the orbiter, specifically designed to search for water on the Martian surface, revealed a cross-section of Mars underground ice exposed on a steep incline, seen here in bright blue after color enhancement. The spacecraft, launched in 2005, continues to operate at Mars, far beyond its intended design life.
These dark features on Mars' mountainous slopes are called recurring slope lineae, or RSL. The MRO, using a compact reconnaissance imaging spectrometer, detected hydrated salts, thus corroborating the hypothesis that the streaks are formed by briny liquid water.
NASA scientists determined as far back as the 1960s that Europa's surface composition is mostly water ice. Decades later, the fourth largest of Jupiter's 95 moons is proving as beguiling as ever. The recent discovery of new types of salty ice could explain the material in the light tan cracks and streaks characteristic of its surface, as well as provide clues on the composition of Europa's icy mantle.
In order to answer that question, any probe would need to burrow through Europa's iron-strength shell to the ocean below. This is because any material vented from Europa's ocean that ends up on the surface is bombarded by deadly radiation. The radiation breaks apart molecules and changes the chemical composition of the material, possibly destroying any biosignatures, or chemical signs that could imply the presence of life.
Europa is thought to have an iron core, a rocky mantle, and a ocean of salty water. This vast body of liquid lies below a shell of ice probably 10 to 15 miles (15 to 25 km) thick, and has an estimated depth of 40 to 100 miles (60 to 150 km). Could this environment support life forms?
Mimas, also imaged several times by the Cassini orbiter, is extremely cratered and outwardly inactive. But, in 2024, researchers based at the Paris Observatory in France revealed data that confirms the presence of an ocean beneath the entire icy surface of the satellite.
And it's hypothesized that the Eridania region in the southern highlands of Mars once contained a vast inland sea with a volume of water greater than that of all other Martian lakes combined. The relatively well-preserved seafloor hydrothermal deposits in Eridania are contemporaneous with the earliest evidence for life on Earth in potentially similar environments 3.8 billion years ago.
Earlier in 2004, NASA's Mars exploration rover Opportunity studied layers in the Burns Cliff slope of the Endurance Crater. It photographed what was later identified as ancient streams and groundwater set above what was once a vast sand dune.
Almost all water on Mars today exists as polar permafrost ice coating the red planet's two poles—the north polar cap (pictured) and the south polar cap.
Enceladus is one of the 146 moons of Saturn. It's also one of the solar system's most scientifically compelling destinations because this small icy world hides a global ocean of liquid salty water beneath its crust.
Scientists attached to NASA's Dawn space probe mission ascertained that Ceres has water seeping onto its surface, suggesting the presence of an ancient underground ocean.
Within this system lies Mimas, another one of Saturn's moons believed to harbor vast reserves of water. Mimas is pictured against the cool, blue-streaked backdrop of Saturn's northern hemisphere.
They deduced this by studying the effect of Mimas' rotation on its orbit caused by small oscillations, called librations. These characteristics can only be explained by the presence of an undulating sea. Their findings were published in the journal Nature on February 8, 2024.
The cloud of water vapor was seen surrounding a supermassive black hole called a quasar. Its presence shows that water has been prevalent in the universe for nearly its entire existence, researchers said.
Sources: (The Planetary Society) (Nature) (NASA Science) (Space.com) (ESA/Hubble)
See also: Mysterious moons of our solar system
Ganymede is Jupiter's largest moon. It's also the largest satellite in the solar system. In 2015, NASA's Hubble Space Telescope found the best evidence yet for an underground saltwater ocean.
Six years later, Hubble discovered evidence of water in the moon's atmosphere, the result of the thermal escape of water vapor from the moon's icy surface.
But it's what lies below that fascinates scientists. Ganymede may hold more water than all of Earth's oceans, but temperatures there are so cold that water on the surface freezes and the ocean lies roughly 100 miles (160 km) below the crust. Pictured is a cutaway view of the possible internal structures of the massive moon.
Launched by the European Space Agency in 2004, Rosetta's lander, Philae, landed on the comet's surface and collected close-up data from its surface. Rosetta determined that the composition of water vapor from Churyumov–Gerasimenko was mixed with significant quantities of formaldehyde and methanol.
A comet's characteristic tail is explained by the melting and evaporation of volatile substances. We know this because of a daring study undertaken in 2014 when the Rosetta space probe rendezvoused with Comet 67P/Churyumov-Gerasimenko.
The interiors of Neptune (pictured) and Uranus each contain about 50,000 times the amount of water in Earth's oceans. These planets are the ice giants of the universe, but their composition is not quite what you'd expect.
Neptune has no definite surface layer. Instead, the gas transits into a soup of slushy ice and water. Both planets may contain an ocean.
Neptune, the eighth and farthest known planet from the sun, is the denser of the two, though slightly smaller. Most of its mass (80% or more) is made up of a hot dense fluid of "icy" material—water, methane, and ammonia. Similarly, below Uranus' 3,000-mile (4,828-km)-thick atmosphere lies a fluid-rich layer not unlike Neptune's.
Beyond the orbit of Neptune, in a region of space that Pluto and most of the other known dwarf planets and some comets call home, is the Kuiper Belt. This flat ring of icy small bodies is so distant from the sun that even gases are in a solid state. This dark, frozen boundary of our solar system is vast and mysterious and little understood.
Comets contain huge amounts of water. And no wonder. These small solar system bodies are essentially cosmic snowballs of frozen gasses, rock, and dust. Pictured is Comet Hale-Bopp seen above the ancient stone circle of Stonehenge in England on March 28, 1997.
Did you know that vast amounts of water exist throughout our galaxy? Much of this is in gaseous form, but scientists believe that some moons and planets within our own solar system harbor huge subterranean oceans.
Billions of years ago, Mars had oceans and rivers. In time, that water disappeared, leaving only ice on the surface, most of it in the polar caps. In 2015, however, NASA scientists confirmed evidence that liquid water does indeed flow on the Martian surface. But it was the discovery in 2022 of a gigantic, 12-billion-year-old cosmic "rain cloud" 700 light-years from Earth that reaffirmed the belief that water has been prevalent in the universe for nearly its entire existence. So, where in space has extraterrestrial liquid been found?
Click through this gallery and launch yourself through a sea of discovery.
How much water is in space?
Where in the universe is extraterrestrial liquid found?
LIFESTYLE Science
Did you know that vast amounts of water exist throughout our galaxy? Much of this is in gaseous form, but scientists believe that some moons and planets within our own solar system harbor huge subterranean oceans.
Billions of years ago, Mars had oceans and rivers. In time, that water disappeared, leaving only ice on the surface, most of it in the polar caps. In 2015, however, NASA scientists confirmed evidence that liquid water does indeed flow on the Martian surface. But it was the discovery in 2022 of a gigantic, 12-billion-year-old cosmic "rain cloud" 700 light-years from Earth that reaffirmed the belief that water has been prevalent in the universe for nearly its entire existence. So, where in space has extraterrestrial liquid been found?
Click through this gallery and launch yourself through a sea of discovery.