Two Types of New Dust Discovered in the Martian Atmosphere: The Environment of Mars

Scientists may have discovered something new about the Red Planet's atmosphere. Satellite-acquired data reveals that dust particles in Mars' atmosphere actually consist of two types, revealing a bit more about the planet.

At the beginning of the Northern summer on Mars and before the sun is completely eclipsed by the planetary disk, its rays pierce through the Martian atmosphere. These beams can then be "caught" by instruments. In this case, the researchers analyzed ultraviolet and infrared atmospheric extinctions from SPICAM, the spectrometer onboard the orbital station, Mars Express.

When the sun's rays go through the atmosphere, they show a different spectrum with the changes hinting at the atmosphere's makeup. By analyzing this spectrum, the scientists can figure out what aerosols there are and the size of their particles. In the end, the scientists found that the dust particles in the Martian atmosphere aren't homogenous. Instead, there are two different types. The first type is coarser and is represented by both H2O ice grains and slightly smaller dust particles. The second type is finer, and is an aerosol which consists of much smaller particles.

This wasn't all that the researchers discovered, though. They found that the density number of both modes of particles is not that high. In fact, even the most dusty layers of the planet's atmosphere have no more than 3 particles of the finer type per 1 cubic centimeter and not more than 2 particles of the coarser type per 1 cubic centimeter. When compared to Earth, the air with such density is actually rather clean.

The findings also reveal that Martian dust storms are able to life large quantities of debris from the planet's surface. The fact that fine dust is present in the atmosphere also contradicts previous data that seemed to show the existence of supersaturated steam at the same altitude. By learning a bit more about the Martian atmosphere, the researchers can better understand the climatic conditions that influence this planet.

The findings have been published in Icarus.