Martian Clouds Contain Less Water Than Predicted

Space.com reported in an article yesterday that clouds over Mars contain less water than what was initially predicted. This was discovered in a simulation lab here on Earth. The clouds, which are being studied at NASA's Ames Research Center, are made of water ice, like many of the clouds on Earth. However, these clouds are forming at very cold temperatures (sometimes below minus 212 degrees Fahrenheit). In the simulation, cloud particles are larger than expected and they fall out of the atmosphere quicker, thus resulting in less cloud mass and a drier atmosphere. Previously, scientists believed that Martian clouds would form at 100% relative humidity, but the new study shows that Martian air needs to be more supersaturated with water to form clouds than scientists thought before. A large ice cap at the north pole of Mars dominates the water cycle. In the northern summer, the ice cap evaporates and wind carries the water to the south pole. The amount of water in the Martian atmosphere changes drastically over time. More studies will follow in an attempt to determine the differences in Mars and Earth's atmospheres.