NASA and the European Space Agency (ESA) have chosen Jupiter's moons as the destination for their upcoming joint outer-planet flagship mission. A trip to Saturn's moon Titan may yet go ahead but needs further investigation, the agencies announced on 18 February.

The Europa Jupiter System Mission will launch two orbiters, one built by NASA and the other by ESA, in 2020, with a scheduled arrival time in the Jupiter system of 2026. The NASA orbiter will study the icy shell of Jupiter's moon Europa — which may hold an ocean capable of supporting life — and will cost US$2.5 billion to $3 billion, says Jim Green, director of NASA's planetary-science division.

The European part of the mission, called Laplace, will investigate Ganymede, the largest moon in the Solar System. It must still compete with two other missions to secure funding.