We only scratch the surface of the information we have on the Solar System’s other planetary bodies.
Nature Astronomy published our new study today. It illustrates how even the most unlikely candidates, such as dunes, can provide insight into weather conditions and other factors encountered if you were to visit distant planets.
What’s in a grain? William Blake (an English poet) famously asked, “see a world made of a grain of sand.”
This was our premise. We wanted to investigate the conditions at the surface of the world using the presence of dunes.
Two criteria are required for dunes to exist. First, the durable but erodible grain must be available.
The wind must blow fast enough to allow the grains to jump on the ground but not too quickly to lift them into space.
It has been difficult to measure wind and sediment on Earth or Mars.
However, we have observed wind-blown sediment features on multiple comets and bodies by satellite.
These dunes signify that the Goldilock’s conditions are being met.
We focused our research on Venus, Earth, Mars, Titan (Neptune’s largest moon), Pluto, and Triton.
What can we do to reconcile the wind-blown features on Pluto’s and Tritons’ surfaces with their fragile and thin atmospheres? Our study predicts which winds will move the sediment and how it will break apart.
These predictions were built by combining the results of many research papers and comparing them with all the experimental data we had.
These theories were applied to six bodies by using satellite and telescope measurements of variables like gravity, atmospheric composition, surface temperatures, and strength of the sediments.
Previous studies focused on the wind speed threshold required to move sand or the strength and density of sediment particles.
In our research, these were combined. We investigated how particles could be reduced in sand-transporting environments on these bodies.
We know that Titan’s Equator contains dunes, but we don’t understand what sediment surrounds them.
Does this organic haze fall from the atmosphere? If winds hit them at Titan’s Equator, loose aggregates will disintegrate.
Titan’s dunes don’t have organic haze. They are built by dragging sediment along the wind for long periods. Dune soils can be traced back as far as a million years ago.
We also found that the wind speed on Pluto would need to exceed light rates to transport methane or nitrogen ice, which is what we hypothesized Pluto’s dune particles to be.
This raises questions about whether the “dunes” found on Pluto’s surface (Sputnik Planitia) are dunes.
Sublimation waves could be the reason.
Our Mars results show that wind-blown sand transport is more common than Earth.
Our models of Mars’s atmosphere may not capture Mars’s powerful “katabatic” winds. These are windy, cold gusts that blow downhill at night.
This is an exciting stage of space exploration.
There is a lot of information about Mars. There are five space agencies currently carrying out active missions on Mars.
Triton has not been visible in the Solar System’s outer reaches since 1989’s NASA Voyager 2 flight.
A mission proposal is available that would send a probe to Triton in 2031 to study its atmosphere before it was destroyed.
In the next decade, missions to Venus or Titan will be launched. This will revolutionize our understanding of these planets.
NASA’s Dragonfly mission, which will launch from Earth in 2027 and land on Titan in 20,34, is scheduled to be found NASA. It will be the uncrewed first landing helicopter on the moon’s dunes.
NASA’s New Horizons mission observed Pluto in 2015. There is no plan to make it back.