A new study is reporting that Mars has snowflakes. They are about the diameter of human red blood cells and are composed of Carbon Dioxide attached to a spec of dust.
The discovery was found after researchers analyzed data from spacecraft [The Mars Global Surveyor (MGS) and the Mars Reconnaissance Orbiter (MRO)] orbiting the red planet, finding that not only does Mars have snowflakes, but they form in clouds similar to those formed on Earth.
During the planet's winter, Clouds of carbon dioxide snow flakes cover the poles and reach about halfway toward the equator. These clouds were discovered through the utilization of MGS's laser altimeter, which was being used to map Mars topography. Occasionally the laser would ricochet off of a cloud much higher in the atmosphere, rather than the surface of the planet.
They measured how much light the clouds reflect to determine the density of each one and determined the total mass of the polar clouds by detecting seasonal shifts in the gravitational field. They put this information together to calculate the number and size of individual snowflakes that reside in the carbon dioxide clouds.
They found that the size of the snowflakes was determined by the pole, the north pole measured between 8 to 22 microns, and the south pole between 4 and 13 microns. These measurements are microscopic and the effectual cloud would look like a dense fog to an observer on the surface of the plant. Researchers say they are about the size of a red blood cell.[source: Space.com]