GALA is a 'laser altimeter' – an instrument that measures the heights and depths of a planetary landscape via the transit time of laser pulses. The GAnymede Laser Altimeter (GALA) for ESA's JUICE ...

Europa is the sixth largest satellite in our Solar System and the smallest of Jupiter’s four Galilean moons. Discovered by ...

At more than 5,000 kilometers (more than 3,000 miles) across, Ganymede rivals Mercury in size, taking first prize for the Solar System's largest natural satellite. The monolith has been a notable ...