Today, the most amazing meteorological phenomenon on Mars is the wind. Periodically, depending on how much different parts of the planet are heated by the Sun, incredible sandstorms rage on the surface of Mars (as observed by Mariner 9). It should be mentioned that the density of the atmosphere at the surface of Mars is much lower than on the Earth, and therefore even extremely violent wind has the effect of a light breeze on our planet (which is just the opposite of what happens on Venus, where the enormous pressure makes a breeze as devastating as a cyclone on the Earth). This should take nothing away from the mechanism that is one of the most efficient means of continuously transforming the surface of the red planet. The dust, which rises to an altitude of a few dozen kilometers, is driven at great speeds against the rocks and may be responsible for the rounded appearance on many mountain slopes on Mars, including Mount Olympus. However, the wind does not only erode: it transports and accumulates the dust in large quantities in all the lower areas of the planet. For example, at the bottom of some of the larger craters there are very large expanses of dunes which have no comparison with those found on the Earth in the great deserts like the Sahara. The forms of the dunes are very similar to those on the Earth and among other things can be used to immediately determine the direction of the wind that deposited them.
Today, the most amazing meteorological phenomenon on Mars is the wind. Periodically, depending on how much different parts of the planet are heated by the Sun, incredible sandstorms rage on the surface of Mars (as observed by Mariner 9). It should be mentioned that the density of the atmosphere at the surface of Mars is much lower than on the Earth, and therefore even extremely violent wind has the effect of a light breeze on our planet (which is just the opposite of what happens on Venus, where the enormous pressure makes a breeze as devastating as a cyclone on the Earth). This should take nothing away from the mechanism that is one of the most efficient means of continuously transforming the surface of the red planet. The dust, which rises to an altitude of a few dozen kilometers, is driven at great speeds against the rocks and may be responsible for the rounded appearance on many mountain slopes on Mars, including Mount Olympus. However, the wind does not only erode: it transports and accumulates the dust in large quantities in all the lower areas of the planet. For example, at the bottom of some of the larger craters there are very large expanses of dunes which have no comparison with those found on the Earth in the great deserts like the Sahara. The forms of the dunes are very similar to those on the Earth and among other things can be used to immediately determine the direction of the wind that deposited them.
