September 8th, 2017 | 1 hr 2 mins
barycentre, copernicus, eclipse, flat earth society, galileo, gravity assist, gravity well, halley's comet, heliocentric, kepler's laws, orbit, voyager, weight versus mass
What are orbits and eclipses?
April 21st, 2017 | 1 hr 1 min
albedo, atmosphere, barycentre, crater, eclipse, extraterrestrial real estate, gravity, lagrange point, mascon, moon, moonquake, regolith, water
What is the Moon?