The Planet Mercury is the closest planet to our sun and is named after a roman god. Learn more about Planet Mercury and the other planets. But the delta V cost breakdown is interesting. Getting into orbit takes just a little bit of delta V. It is making sure you stay in space that takes a freaking 21st Century Earth History Introduction. When Gene Roddenberry conceived Star Trek in the 1960s, there was unanimous enthusiasm about space travel and other. The earth passes through four seasons as it orbits the sun, along with increasing daylight length in the six months between the winter and summer solstice.