Space and time

A message to Mars takes between 3 and 22 minutes, and a day there is 39 minutes longer than ours. This topic starts with how fast light is and climbs to distances in space, clocks and calendars on Mars, and Einstein's relativity, which a navigator to Mars must take into account.

8 levels. The ages are only a rough guide for parents and teachers; anyone can start at any level.

Level	Rough age	What it covers
Level 1: Day and night	5-6	Why we have day and night, a day on Mars
Level 2: Near and far	7-8	How far Mars is, a model of the solar system to scale
Level 3: How fast is light?	9-10	Light takes time, talking to a rover with a delay
Level 4: Clocks on Mars	11-12	The sol, Mars time, the Mars year and its seasons
Level 5: Measuring the sky	12-13	Angles, parallax, astronomical units and light-minutes
Level 6: Light delay	13-14	Planning commands across 3 to 22 minutes, signals behind the Sun
Level 7: Special relativity	15-16	The speed of light is the same for all, time dilation, E = mc²
Level 8: Gravity and time	17 and beyond	General relativity, clocks on Mars run faster, how navigation corrects for it