Elon Musk just declared that his spaceflight company, SpaceX, could use it biggest rocket to send a crew-carrying spacecraft all the way to Jupiter. The giant planet Jupiter is itself an inhospitable hellhole. But planetary scientists have eyed one of its moons, Europa, for years.
Researchers are convinced that below Europa’s icy crust, a warm, salty ocean exists that contains more than twice as much water as all of Earth’s reserves combined. That vast subsurface ocean could mean Europa is the most likely place we could find alien life in our Solar System.
The "Falcon Heavy" is Musk’s next planned rocket. SpaceX has yet to build and launch one, but the company’s website states that the 230-foot-tall machine could be ready as soon as 2016 and lift "a 737 jetliner loaded with passengers, crew, luggage and fuel" into orbit around the Earth.
The "Dragon," meanwhile, is SpaceX’s capsule that can ferry people and supplies into space. (Musk recently used Instagram to show how he envisions using a Dragon to send humans to Mars.)
The last spacecraft we sent to Europa was NASA’s Galileo spacecraft in the 1990s. Galileo couldn’t hold people or supplies, it was a robotic probe, and it wasn’t equipped with the right instruments to investigate all of the secrets scientists now suspect Europa holds.
Europa’s giant ocean exists due to Jupiter’s massive size. The planet’s huge gravitational pull pushes and pulls on the ice moon’s rocky core, heating up the interior with enough friction that scientists believe it could melt ice into liquid water.
If enough nutrients are floating around in that water, it might contain life similar to the bacteria and tiny creatures that hang around hydrothermal vents at the bottom of Earth’s oceans. Or, if Europa’s ocean is exceptionally habitable, the moon may even have the potential to sustain larger lifeforms.