Space
Orbits, distance, and the mechanics of going anywhere.
The solar system, to scale
Explore the Sun, eight planets, thirteen moons and four spacecraft, with sizes and distances shown on the same scale.
Why is it hard to fly above the solar system?
The planets orbit the Sun in roughly the same plane. Sending a spacecraft steeply out of that plane takes a large change in motion, because it starts with Earth’s orbital speed.
Trajectories to other planets
Reaching another planet means planning for where it will be when the spacecraft arrives. Explore how the departure date changes the journey.