Dust devils suspected in the creation of dunes on Titan

Astronomers came to the conclusion that the key role in the creation of sand dunes on Saturn’s moon Titan can play dust devils that occur on Earth and Mars and is able to emerge on Titan. Talking about this meteorological data obtained spokeman apparatus “Huygens”. Article published in the journal Journal of Geophysical Research: Planets.

Titan is the largest moon of Saturn. It is unique in that it has a dense opaque atmosphere mainly of nitrogen, with atmospheric pressure near the surface of the satellite is 1.5 times more than on Earth. It is also the only celestial body in the Solar system besides our planet has liquid lakes and seas from a mixture of methane and ethane, in which dissolved nitrogen.

The atmosphere of the satellite is rich in aerosols of organic substances, which are formed in the thermosphere during the photolysis of molecules of N2 and CH4, and then slowly deposited on the surface of Titan. Interplanetary station “Cassini” found that the satellite have an active Aeolian processessuch as the weathering of rocks by wind transport of dust produce landforms, and 13 percent of its surface covers the fields of giant sand dunes, located in the Equatorial part of Titan. Granules of sand may have a size from 5 to 200 micrometers, and their possible source are called aerosols from the atmosphere of the satellite.

Cassini also recorded in 2019 on Titan three local dust storms near the equator. This not only confirms the active dust cycle, but also suggests the possibility of occurrence of other such phenomena, such as dust devils. These dust whirlwinds associated with the processes of convection has been observed on Earth and on Mars. If the Titan there are dust devils, then they can be responsible for the transport of dust and the formation of dunes.

A team of astronomers led by Brian Jackson (Brian Jackson) from Idaho state University decided to test the possibility of the existence of dust devils on Titan. For this purpose, they used the meteorological data obtained spokeman apparatus “Huygens”, which in 2005 for the first time in history, made a soft landing on the moon’s surface. The researchers compared these data with the parameters of the devils seen on Earth and Mars. In particular, they studied the relationship between pressure, temperature, wind speed and ability of the devil to raise dust into the air.

Scientists came to the conclusion that dust devils, as a small convective vortices can form on titanium, and can play a key role in aiolova cycle. The diameters of the devils depend on the depth of the planetary boundary layer and h can be either 88 meters (for h = 440 metres) and 520 metres (for h = 2.6 km). The tangential wind speed in the eye of the vortex was estimated at a few meters per second, enough to lift dust particles with a size of five micrometers.

The problem of detection and study of such vortices, in practice, scientists lay on the Dragonfly mission. In the framework of 2034 on Titan will be planted oktokopter, whose goal will be the study of the surface and atmosphere of Saturn’s moon. He will be able to determine the weather conditions necessary for the formation of convective vortices to their panoramic images and to determine the amount of borne particles of dust.

Earlier we talked about how looks the first geomorphological map of Titan, how NASA sent to Saturn’s moon oktokopter and what was explained to disappearing island on Titan.

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