Nasa is planning to launch a landing probe to Jupiter's moon Europa by mid-2020s in the hope of discovering alien life on the ocean-harbouring moon.
While the main thrust of the Europa mission, which Nasa aims to launch by the mid-2020s, involves characterising the icy satellite from afar during dozens of flybys, the space agency is considering sending a small probe down to the surface as well.
"We are actively pursuing the possibility of a lander," Robert Pappalardo, Europa project scientist at Nasa's Jet Propulsion Laboratory (JPL) said last week during a panel discussion at the American Institute of Aeronautics and Astronautics' Space 2015 conference in Pasadena.
"Nasa has asked us to investigate: What would it take? How much would it cost? Could we put a small surface package on Europa with this mission?" Pappalardo added.
Nasa has also asked the European Space Agency if it would be interested in contributing a lander, ice-penetrating impactor or other piggyback probe to the roughly USD 2 billion Europa mission, Space.com reported.
Europa is covered by an ice shell perhaps 80 kilometres thick, but underneath this crust is thought to lie a huge ocean of liquid water about 20 kilometres deep.
At least five other moons in the solar system are believed to harbour such subsurface seas, Kevin Hand, deputy chief scientist at JPL's Solar System Exploration Directorate, said.
However, only the oceans of Enceladus and Europa are likely in contact with the rocky mantle, a scenario that makes all sorts of interesting chemical reactions possible, he added.
The as-yet-unnamed Europa mission could launch as early as 2022. After reaching Jupiter orbit, the robotic probe will perform 45 flybys of Europa over the course of 2.5 years or so.