(ORDO NEWS) — And if you end up on the surface of Mars or Venus? Or even further away, like Pluto or Saturn’s moon Titan?
This curiosity has driven progress in space exploration since the launch of Sputnik 1 65 years ago. But we’re just scratching the surface of what we can learn about other planetary bodies in the solar system.
What is in a grain of sand?
The idea of the study was to study sand dunes to understand what conditions exist on the surface of the planet.
For dunes to exist at all, a couple of criteria must be met. First, the presence of erosive, but strong grains is necessary.
Second, the presence of winds fast enough to make these grains bounce across the surface, but not so fast as to blow them high into the atmosphere.
Until now, direct measurement of winds and precipitation has only been possible on Earth and Mars. However, researchers have observed windblown sediments on many other bodies (and even comets) using satellites. The very presence of such dunes on these bodies suggests that the conditions are met.
The work of scientists was focused on Venus, Earth, Mars, Titan, Triton (the largest moon of Neptune) and Pluto. Unresolved disputes about these bodies have been going on for decades.
The study presents forecasts of the winds required to move sediment on these bodies and how easily these sediments will be eroded by the winds.
These predictions are made by piecing together results from a variety of other scientific papers and testing them against all the experimental data that could be obtained.
The theory was then applied to each of the six bodies, drawing on data from telescopes and satellite measurements of variables including gravity, atmospheric composition, surface temperature and sediment strength.
As it turned out, loose aggregates of organic haze disintegrate upon collision, if they are blown by the winds at Titan’s equator.
This means that the dunes of Titan are probably composed of more than just organic haze. To form dunes, sedimentary rocks must be blown away by the wind for a long time (some terrestrial dunes are millions of years old).
It has also been found that the wind speed on Pluto must be too high to carry methane or nitrogen ice (which, according to the hypothesis, are Pluto’s dune deposits). This calls into question whether the “dunes” on the Pluto plain are dunes at all.
Instead, they may be sublimation waves. These are dune-like landforms, and not erosion of sedimentary rocks (as, for example, on the northern polar cap of Mars).
Missions planned to Venus and Titan over the next decade will revolutionize our understanding of these two planets. NASA’s Dragonfly mission, due to leave Earth in 2027 and arrive on Titan in 2034, will land a drone on the moon’s dunes.
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