Great news! In just ten years we will see two space travels explore one of the most habitable places in the solar system beyond Earth (if we exclude Saturday evening).
Life on Europe: it would be an extraordinary discovery. The exciting announcement to NASA that it gave the green light to Europa Clipper makes everyone dream. The first orbiting spacecraft will reach Jupiter's moon in the early 30s of the new millennium. Astronomy says it clearly: we will not find life on Jupiter, that planet is also quite thorny to visit, but we can well hope for its satellite.
The go-ahead of the mission on europa is coupled with that of ESA, which 4 months ago started the development of JUICE, which stands for Jupiter Icy Moons Explorer. JUICE will precede the Clipper a little, will arrive in Europe in just over 9 years.
At the dawn of the space age, everyone imagined that all life depended on the energy of the sun. The icy moons of the outer planets were considered the last place to look. The discovery of entire ecosystems in the depths of the Earth's ocean depths has completely changed the perception of it.
Curiously, we now know that life can also be born "without the sun", and indeed the ice may have protected and accompanied its development.
Europe, the cradle of life?
Europa can host in its liquid body an ocean under ice caps, life of all kinds, from the microbial one onwards.
This is because it contains 3 essential prerequisites to life: an energy source, a liquid solvent where interacting chemicals dissolve, and biochemical molecules.
The energy of Europa derives from the combination of its orbit around Jupiter and the gravitational interaction between the two celestial bodies and two other moons. This combination of forces allows for gravitational changes on Europa at each orbit: a kind of "vibration" that prevents the water from freezing completely.
The presence of biochemical molecules on Europa, if not coming from the star's core, is guaranteed by ascertained impacts with comets in the (relatively) recent past.
An "icebreaker" radar
Both Europa Clipper and JUICE will carry a special radar to "pierce" the frozen surface of Europa. Technologies not recent but effective, if you consider that both in Antarctica and on Mars have done their duty very well in scanning the subsoil.
The search for life on Europa seems the ideal gym for this technology, because the colder the ice, the clearer the response to radar. The average temperature in Europe is -170 ° C. Current estimates say that between 15 and 25km of depth there is liquid water.
The Hubble Space Telescope has indeed located many cases where liquid water is even closer. In the southern hemisphere it even emerges to the surface in the form of "icy feathers" and crystallizes instantly, like lava from a volcano.
JUICE and Europa Clipper, "studying" ice and gravitational anomalies, aim to understand which is the best or most promising point to look for. After them will come probes that will actually start piercing the ice.
The challenges to face
The next generation of probes will encounter many more problems than JUICE and Europa Clipper. A drill will not be enough to collect any life samples: for kilometers of ice as hard as granite, a laser will be needed, or perhaps nuclear reactors to be allowed to melt inside to make way. Maybe a small submarine to be lowered into the "hole" made.
Even in the case of areas with thin ice and water close to the surface, it will not be easy to bring "heavy" vehicles up there. Europa's proximity to Jupiter creates a strong gravitational field that requires a lot of speed and a lot of fuel to avoid being caught by it. JUICE will also find complications in exploring Ganymede, another moon of Jupiter. To visit it you will need 3000kg of fuel.
The presence of strong radiation from Jupiter it constitutes another danger for the spacecraft: for this reason the Clipper will make very wide orbits, in order to resist as long as possible.
We do not forget the absence of a dense atmosphere on Europe: another problem that will force you to maneuver without parachutes or brakes of some kind. Everything can only be achieved with rockets, increasing the use of fuel.
Did you think it was over? There are also the problems that we will bring: Europe is currently a completely unspoiled environment. Tasks such as those we have set ourselves could contaminate it with rocket fuels, or with terrestrial microbes that we will have brought by mistake (they always tend to pocketing clandestine passengers).