Oh, the Sahara dust plume will be mostly done by the time you read this. We had hazy skies, our allergies got pumped up, and it of course exacerbated serious respiratory health issues. Weather forecasters had a fun couple of weeks with it.
Could be worse. You could be living in the Sahara or other desert that experiences severe dust storms periodically. Good thing is they come and then are over and its clean-up time. Move to Mars and find out about dust storms!
Mars was once the object of romantic ideas, where living beings built a planet-wide network of canals that supplied water everywhere. It was also the object of scary scenarios where malevolent living beings existed, bent on our destruction. Most sci-fi focused on the latter, Mars as a dangerous place with blood thirsty creatures. H. G. Wells’ War of the Worlds comes to mind.
Once we got a closer look at Mars ideas changed. No longer was it a place of life, no matter the kind. It is a place of no life that we know of.
Mars lost its magnetosphere about 4 billion years ago, so its surface is bombarded by solar wind protons, electrons, and alpha particles. Mars has an atmosphere, mostly CO2 and way thinner than at the top of Mount Everest. You’d have to reach 115,000 feet above sea level on Earth to equal the average atmospheric pressure on Mars, so no protective atmosphere filtering UV. Mars’ surface is likely sterile, not currently a great place to homestead.
Mars’ was at opposition on July 27, 2018 and I had set up a telescope in our front yard so neighbors could check it out. What did we see? A bright orange ball with no surface markings visible. Sure, the color was cool but that lasts about 10 seconds before the words come out, “is that all?” Mars was experiencing a planet-wide dust storm.
Mars dust storms start much like dust storms and thunderstorms start on Earth. As sunlight warms the planet’s surface, atmosphere close to the ground rises into the cooler upper layers. The instability that ensues causes variable winds, dust devils, and dust storms with up to sixty mile-an-hour wind. Large storms combine into planet-wide storms about every 3 years. A Mars dust storm can last weeks to months!
We are sending astronauts to Mars in a few years and they need to be ready for Martian dust storms. Fortunately, their habitats will be fully sealed and have airlocks to serve as foyers. Power is the real issue. Dust will coat solar panels, reducing output.
Due to Mars’ extremely thin atmosphere, dust storms are unlikely to blow over any equipment or even the astronauts themselves.
What’s in the Sky?
July 14; late night; east-southeast: Jupiter is at opposition. Saturn’s next.
July 17; before sunrise; east: A waning crescent Moon, Venus, and Aldebaran (Taurus) are well above the horizon