Jupiter has often been referred to as the King of Planets, and for good reason, as it is a massive gas giant, much larger than Earth and the largest planet in our Solar System. It is more than 2.5 times as massive as all the other planets combined, and is a mesmerizing world of colourful bands of clouds wrapping around the globe, which can be seen even in a small telescope, but exhibit incredible detail when seen by spacecraft. Jupiter is also itself the center of a sort of miniature solar system, with dozens of moons orbiting around it. We’ve seen this world up close before by spacecraft such as Voyager and Galileo, but now a new visitor has arrived in the Jovian system: NASA’s spacecraft Juno.
The impact of comet Shoemaker-Levy 9 into Jupiter in 1994 was a spectacular event for astronomers. The scars in Jupiter’s atmosphere lasted for weeks afterward; while those have long since faded, there are still other features of the impact visible even now, it was announced last Tuesday.
These are a couple of great images from many years ago, taken by the Voyager 1 spacecraft as it passed Jupiter. The first, in dramatic black & white, shows the moon Europa (with its subsurface ocean) passing in front of Jupiter’s turbulent clouds below, including the Great Red Spot on the left. It kind of looks like a Van Gogh painting, but it’s very real.
As one of the few places in the solar system other than Earth known to have an ocean, Europa has become one of the most fascinating worlds that we know of. This moon of Jupiter is small, but enticing – beneath its frozen surface of ice is a global ocean of water, making it a primary focus of study, especially in terms of the search for life elsewhere.
Jupiter’s moon Europa is often referred to as a “waterworld,” and for good reason: a global ocean almost definitely exists below its outer icy crust, making it a primary focus of interest in the search for life elsewhere in the solar system. So far, most of the information we have about this fascinating moon has come from flybys of the Galileo and Voyager spacecraft; these missions have been invaluable, of course, although limited. If we want to learn more about what is going on below in the Europan ocean, it will require new spacecraft with the necessary instruments to carry out long-term studies. Budgets are tight for an orbiter or lander, but a newly proposed “clipper” mission may just fit the bill.