The Cassini spacecraft has made some truly remarkable discoveries within the Saturnian system, where it has been orbiting for the last 13 years. One such discovery is of the walnut-shaped moons: Atlas, Daphnis, and Pan. These moons sport a prominent equatorial ridge pattern circumnavigating the moons (Saturn's moon Iapetus also as an equatorial feature, though not as prominent as these). The ridges are due to where the moons are located. They are all located in or very near to the ring system

Late last year, Elon Musk gave a talk at the 67th International Astronautical Congress outlining why he believes humans need to be a multi-planetary species, and how he plans to do it. Musk's talk, which you can watch here, has also been transcribed into this helpful document. This is a plain-language description of putting humans on Mars written by one of the leaders in the game. It's worth a read (or a watch).