New type of dust in Martian atmosphere discovered

Jun 23, 2014

A group of French and Russian scientists, including three specialists from Moscow Institute of Physics and Technology, has discovered a new peculiarity of the Martian atmosphere. The scientists had analyzed satellite-acquired data and concluded that the dust particles in the planet's atmosphere can be of two types. The scientific article which presents the results of the research in detail has been published in Icarus.

The Russian contributors to the research, Anna Fedorova, Alexander Rodin and Oleg Korablev, are the specialists of MIPT and SRI (IKI) RAS. These scientists and their French colleagues from the Paris Observatory and LATMOS research laboratory have carried out a simultaneous analysis of the ultraviolet and infrared atmospheric extinctions from SPICAM, the spectrometer on the board of the orbital station Mars Express.

The results were received during the solar occultations at the beginning of Northern summer on Mars. Before the Sun is completely eclipsed by the planetary disk, its rays pierce through the atmosphere and then get "caught" by the spectrometer's detector. Having gone through the atmosphere, the solar rays show a different spectrum with the changes hinting at the atmosphere's makeup, the amount of various aerosols and the size of their particles. This method was applied in order to understand the way the particles are distributed in the atmosphere.

The researchers have found out that the in the Martian atmosphere are not homogeneous, but can be roughly grouped into two modes. The first – coarser - mode is represented by both H2O with the average radius of 1.2 μm, and slightly smaller dust particles (R = 0.7 μm).

The second mode is a lot finer, it is an aerosol which consists of much smaller particles with a radius of 0.04–0.07 μm.

Interestingly, the density number of the both modes is not that high. Even in the most "dusty" layers of the planet's atmosphere at altitudes of 20–30 km there are about 3.000 particles of the finer mode per 1 cm³, and not more than 2 particles of the coarser mode per 1 cm³.

If compared with what is considered the norm on Earth, the air with such dust density is rather clean (rooms are usually a lot dustier); yet, aerosols are important because they, according to the scientists, play a key role in forming the planet's climate.

Because of fine dust particles in the higher layers of the atmosphere, ice "embryos" are formed faster, which, in turn, influences clouds' build-up. The clouds are responsible for both precipitation and temperature condition on the planet's surface. Analyzing the way the dust is spread in the atmosphere of the planet with regard to the altitude and geographical coordinates is crucial for forming the full picture of what is happening on Mars.

Besides that, the dust modes which the scientists have discovered confirm that Martian dust storms ("dust devils") are able to lift large quantities of substance from the planet's surface.

The researchers point out that the fact of fine dust presence in the atmosphere can contradict the previously obtained data on the existence of the supersaturated steam at the same altitude.

With the extraneous particles present it would have been natural for the supersaturated steam to get further condensed and form clouds. The key to the solution of this contradiction is, presumably, that there are very low temperatures of about – 110 degrees Celsius. At such low temperatures the growth of ice grains slows down substantially.

Studying the clouds' build-up in the higher layers of the is important not only to understand what is typical for Mars, but also to know more of Earth, because similar processes can be here occurring as well.

Explore further: Researchers suggest Greenland ice shelf melting faster due to embedded dust particles

More information: Icarus,… ii/S0019103513005332

add to favorites email to friend print save as pdf

Related Stories

Recommended for you

Historical comet-landing site is looking for a name

28 minutes ago

The Rosetta mission reaches a defining moment on Wednesday November 12, when its lander, Philae, is released. After about seven hours of descent, Philae will arrive on the surface of Comet 67P Churyumov-Gerasimenko. ...

Image: Siding Spring grazes Mars

1 hour ago

This excellent view of Mars seen together with Comet C/2013 A1 Siding Spring was captured by Scott Ferguson, Florida, USA, on 19 October 2014 on the morning that the enigmatic object made the closest-known ...

China to send orbiter to moon and back

4 hours ago

China will launch its latest lunar orbiter in the coming days, state media said Wednesday, in its first attempt to send a spacecraft around the moon and back to Earth.

NASA Webb's heart survives deep freeze test

14 hours ago

After 116 days of being subjected to extremely frigid temperatures like that in space, the heart of the James Webb Space Telescope, the Integrated Science Instrument Module (ISIM) and its sensitive instruments, ...

Cosmic rays threaten future deep-space astronaut missions

19 hours ago

Crewed missions to Mars remain an essential goal for NASA, but scientists are only now beginning to understand and characterize the radiation hazards that could make such ventures risky, concludes a new paper ...

User comments : 0