Humankind has always been fascinated with space. In some of the earliest recorded history, ancient Greeks and Romans both made references to the Milky Way.
Long before humans could consider sending civilians to space or exploring other planets, Edwin Hubble discovered the distance to the Andromeda Galaxy. Before that, astronomers thought everything in the universe existed within our own Milky Way. Scientists now predict there are at least 100-200 billion galaxies and an indeterminate amount of stars.
With all of the progress the world's space programs keep making, it can be hard to keep up with the latest information. For starters, astronauts can now grow their own food on the International Space Station, and NASA's Osiris-Rex spacecraft is studying an asteroid named Bennu, hoping to get some answers about the early days of the solar system.