- Europa, Jupiter's moon, is covered by a 30 km thick solid ice shell
- A vast liquid ocean exists beneath Europa’s icy crust, warmed by tidal heating
- Europa’s ocean may contain water, chemical elements, and an energy source
Jupiter's moon Europa may appear like a frozen, lifeless world covered in ice, but scientists believe it could be one of the most promising places to search for life beyond our Solar System, reported BBC. Europa is covered by a thick shell of solid ice that is almost 30 kilometres thick. The moon faces intense radiation from Jupiter, and its surface temperature remains below -160 degrees Celsius. Despite these harsh conditions, scientists believe a vast ocean of liquid water exists beneath its icy crust.
Researchers estimate that Europa's hidden ocean contains more than twice the water found in all of Earth's oceans combined. The ocean is warmed by Jupiter's gravitational pull, which stretches and flexes Europa's interior through tidal heating. Scientists believe this underground ocean may have three important ingredients needed for life: liquid water, chemical elements, and an energy source.
Europa has a mean radius of around 1,500 kilometres and is smaller and lighter than Jupiter's other three large Galilean moons, Ganymede, Callisto and Io.
The moon cannot be seen with the naked eye, but it can be observed with binoculars or a small telescope when Jupiter is at its best.
Europa's outer surface is completely made of water ice, giving it a high ability to reflect sunlight. Beneath the icy crust, the moon has an iron core surrounded by a mantle of magma, mostly made of silicate rock.
Unlike Earth, which has a rocky crust and oceans above it, Europa has an icy crust with a large liquid ocean below.
Scientists have also found evidence that Europa's icy crust may have plate tectonics. Similar to Earth's moving rocky plates, giant plates of ice on Europa may slide over or under each other.
Although Europa itself is around 4 to 4.5 billion years old, its surface is believed to be between 20 million and 180 million years old. Scientists know this because the moon has very few impact craters, making it the smoothest surface of any solid object in the Solar System.
Europa completes one orbit around Jupiter every 3.55 Earth days.
Most of Europa's energy comes from tidal heating. Its slightly tilted axis, egg-shaped orbit around Jupiter, and gravitational interactions with other Galilean moons create a constant push and pull that heats its interior.
Europa also has a thin atmosphere that extends up to 190 kilometres above its surface. The atmosphere mostly contains molecular oxygen, created when radiation from Jupiter breaks down water ice on the surface. However, the amount of oxygen is not enough for humans to breathe.
