SUMMARY The Sun is the closest star to Earth. Only thanks to the Sun life, as we know it today, exists. Plants convert solar energy into chemical energy, they give us oxygen to breathe, and so you can go the beach and have a sunbath. Just imagine our planet, all frozen, traveling through the Universe for billions of years, still conserving what is left of life before the Sun «left» us. Maybe one day it would come close enough to a different star and get into its gravitational pull and star orbiting around it. In this case, the ice would melt, and the planet would heat so those microbes would have a chance to evolve into other types of life. But in such conditions, the chances that humans would appear as a result of this evolution are slightly bigger than zero.
Text source: YouTube video description