Can you tell the difference between California, Venus, Titan and Mars? Hint: California is the one with buildings.
Californians woke up to an alien-looking sky this morning, Wednesday, September 9, 2020.
Dense smoke and ash from the ongoing wildfires have been blown high into the upper atmosphere, blocking nearly all sunlight. This is due to extremely intense fire updrafts, according to climate scientist Daniel Swain. He said on Twitter that the smoke particles have been lifted as high as 50,000 feet (15,000 meters) which is 20,000 feet (6,000 meters) above cruising altitude of jet airliners.
The apocalyptic view had several planetary scientists comparing the sky to those of other worlds in our solar system. Cue Katie Mack:
What are the similarities and differences between Earth’s atmosphere and other worlds like Venus, Mars and Titan? Katie Mack mentioned the hydrocarbons that float in Titan’s thick atmosphere, so let’s look there first.
Titan, the second largest moon in our solar system, has a dense, shroud-like atmosphere made mostly of nitrogen, like Earth’s, but with a surface pressure 50 percent higher than Earth’s. Titan has clouds, rain, rivers, lakes and seas of liquid hydrocarbons such as methane and ethane. NASA says that lakes and seas on Titan’s surface, also made of liquid hydrocarbons, could conceivably harbor life that uses different chemistry than we’re used to. Or, Titan could also be a lifeless world. One day we hope to find out.
Venus also has a thick atmosphere, which consists mainly of carbon dioxide, with clouds of sulfuric acid droplets. The thick atmosphere traps the Sun’s heat, resulting in surface temperatures higher than 880 degrees Fahrenheit (470 degrees Celsius). We discussed in a recent article how about 30 miles up from the surface on Venus, it’s about the same temperature and atmospheric density as on the surface of the Earth.
But the top level of clouds zips around the planet every four Earth days, driven by hurricane-force winds traveling at about 224 miles (360 kilometers) per hour. Atmospheric lightning bursts light up these quick-moving clouds. Speeds within the clouds decrease with cloud height, and at the surface are estimated to be just a few miles per hour.
If you could somehow stand on the surface of Venus, the view of the sky would look like a very hazy, overcast day on Earth. But the atmosphere is so heavy it would feel like you were 1 mile (1.6 kilometers) deep underwater.