GALERIE FOTO: Motivul pentru care discul de aur al lui „Voyager”, sonda spațială aflată în afara Sistemului Solar, conține o mică mostră de uraniu

CALLISTO 10 March 1995 This close up of Callisto shows the heavily cratered surface and the prominent ring structure known as Valhalla. It was acquired by Voyager 1 on March, 6 1979. Valhalla's bright central area is about 300 km across with sets of concentric ridges extending out to 1,500 km from the center. Credit: Calvin J. Hamilton, and NASA.