‘All these worlds are yours – except Europa. Attempt no landing there.” Thus spoke the mysterious aliens in Arthur C. Clarke’s 2010: Odyssey Two (as well as its film adaptation). Better-known as the beings behind the monolith in Stanley Kubrick’s adaptation of 2001: A Space Odyssey, the previous novel, these aliens discover aquatic life swimming beneath the surface of Jupiter’s icy moon, decide to transform Jupiter into a star to aid their evolution — and ban humans from it (though not the planet’s other three moons).
NASA’s Europa Clipper, the agency’s largest-ever robotic probe, isn’t planning to violate this proscription. Launched Monday (with a SpaceX assist), it will instead perform dozens of flybys of Europa, though it will at times come quite close to the surface — close enough possibly to sample and assess plumes of water vapor hypothesized to arise from the moon.
Why the interest in Europa, for both Clarke and NASA? Because it has perhaps the best probability of harboring life of any astronomical body in our solar system besides our own. As the Washington Post puts it: “The scientific community has been fascinated by Europa for decades. Multiple lines of evidence suggest there is a deep, salty ocean beneath the surface. Although Europa is icy at the surface, tidal forces created by Jupiter’s immense gravity squeeze the moon’s icy crust and generate heat to keep the subsurface water liquid, scientists suspect.”
The mission, which will cover 1.8 billion miles, take five and a half years, and include a Martian flyby, is not intended to discover life on Europa; merely to determine whether it could harbor life beneath its frozen surface. “We don’t expect fish and whales and that kind of thing,” Europa Clipper chief scientist Robert Pappalardo of the NASA Jet Propulsion Laboratory said. Maybe they’ll find a monolith instead.