Twin systems Double planets Binary planets Biplanetary systems
Enterprise Columbia Atlantis Discovery
9 3 7 5
The Hoyle Equation The Hawking Equation The Sagan Equation The Drake Equation
Orbiting Neptune Asteroid Belt Jupiter Ring System Kuiper Belt
Titan Io Callisto Ganymede
Titan Io Europa Mars
Leda Phobos Deimos Calypso
149 million km/second 299 million km/second 186 million km/second 93 million km/second
WAC Corporal Explorer 1 Sputnik 1 V2 Missile