Europa is one of Jupiter’s 79 moons. It is one of four large moons that revolve around the planet, and is slightly smaller in size than our moon. Europa was discovered in 1610 by Galileo Galilei, and has the distinction of being the first moon found orbiting another planet in our solar system.
While Europa was the first of Jupiter’s moons to be discovered, it is also the most intriguing from the perspective of planetary scientists. Oxygen and water have been detected in its thin atmosphere, and it is known to have a massive ocean somewhere below the depths of its frozen surface. Estimates are that this ocean is 100 kilometres deep and has twice the volume of water of all the oceans on Earth combined.
And where there’s water, there could be life. Planetary scientists know this, and that is why they’ve identified Europa as a place worthy of exploring.
The Plumes of Europa
In 2014 and again in 2016, scientists observing images from the Hubble space telescope found confirmation of water on Europa, and in significant amounts. They were shocked and delighted to see vast, arcing plumes of liquid water spurting from the surface of the planet. Estimates are that these plumes were between 50 and 100 kilometres in length, and in each occasion they emerged from the same location on the planet’s surface.