If you haven’t seen news of the recent anniversary of the first man on the moon,you’ve probably been in inensive care. I watched the story of the moon landing on PBS. It was good to review the history of years condensed into a few programs. It was clear that Mars was deemed the next goal. NASA and the Soviets sent unmanned rockets into space to explore several planets and their moons besides Mars over the years. Such missions almost became routine.
Science fiction creatures from outer space seem inevitably to be Martians. Loss of life probably made NASA more cautious about humans landing on Mars, but the idea lingers. National Geographic ran an excellent series called Mars—a mix of a suspenseful fictional story with a history of efforts to explore Mars. Andy Weir’s novel, The Martian was so popular it was made into a movie. Both the National Geographic series and The Martian gave me a real sense of what the planet must look like.
Elon Musk sent a Tesla roadster to Mars in February 2018. It makes sense since there probably aren’t any gas stations there.
Despite all of what has been said about Mars, I was surprised to watch a Nova program on Mars and learn that scientists think that 4 billion years ago, Mars had tons of water: basins, flowing rivers, a magnificent waterfall, and possibly an ocean. Numerous landings sent back information on the shape of the terrain and the nature of the soil and rocks, providing evidence for water having been there. In fact, it appears that Earth, Mars, and other planets were similarly formed and were much alike originally. Only Earth retained its oceans.
So, what happened to the water on Mars? It turns out that Mars has a thin atmosphere, and is smaller, meaning weaker gravity and magnetic field determined by the size of its core. Earth’s gravity and magnetic field keep our molecules close to Earth, but Maven, which has orbited Mars in an elliptical orbit so that it varies between 150-6,000 kilometers from Mars, measures the number of molecules in Mars’s atmosphere. It loses two to three kilograms per second. The water has escaped over time.
If early conditions did match those of Earth, scientists wonder if life also began on Mars. They hope to find out.