Earth Day, without Earth? Envision it with a Free Ebook This Weekend.

Isn’t every day Earth Day? We don’t have any days on Mars or the newly discovered exoplanet orbiting dwarf star LHS 1140 (yet). Astronauts had a few days on the moon in the 1960s and 70s, but for most of the seven billion humans in the universe, the only days we have are Earth days. … Continue reading Earth Day, without Earth? Envision it with a Free Ebook This Weekend.