Jupiter is not only our solar system’s most visually striking planet, it is also surrounded by a large number of moons — one of which is a promising location to search for life. Europa, one of the closest and largest of Jupiter’s 79 moons, has an icy crust which experts think could be hiding an ocean where life could potentially flourish.
Now, a new image from the Hubble Space Telescope captures both Jupiter and Europa in delightfully sharp detail.
Jupiter is full of surprises, and this image shows how the weather on the planet is changing — especially in the Great Red Spot, the large circular structure shown in orange which is a superstorm stretching nearly 10,000 miles across. That means this spot is so large it could swallow the Earth in its entirety.
This huge spot isn’t static though — it has actually been shrinking since early observations in the 1930s, but that shrinking seems to have slowed down and astronomers aren’t sure why. Another open question is why the spot is the color it is, in the attention-grabbing bright orange, as most storms on Jupiter appear white or brown. And its color changes over time as well, with this image showing it a more rich reddish color than it has been previously.
As for Europa, you can see it to the left of Jupiter. Hubble has previously observed water vapor being ejected from the moon’s surface which could be linked to liquid water beneath the icy crust. But it’s hard to know for sure what these plumes of water mean until we can study it up close. For that purpose, the European Space Agency is launching a mission to Jupiter’s moons in 2022, called JUICE (JUpiter ICy moons Explorer), which will explore Europa as well as its sibling moons Ganymede, Callisto, and Europa, to learn more about the ocean which could be hiding beneath the ice.