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The dust that covers much of the surface of Mars comes largely from a geological formation of a thousand kilometers near the equator of the red planet, have discovered the scientists .
A study published in the journal Nature Communications found a chemical correspondence between dust in the Martian atmosphere and the surface feature, called the Medusae Fossae Formation.
"Mars would not be so dusty if it was not for this huge deposit that gradually erodes over time and pollutes the planet, essentially," said co-author Kevin Lewis, Assistant Professor of Earth Science and Planets at Johns Hopkins University
film The Martian, a dust storm leads to a series of events that strands an astronaut played by actor Matt Damon As in the movie, the dust on Mars caused problems for real missions, including the Spirit Mars Exploration Rover .The fine and powdery particles can penetrate into expensive instruments and obscure the solar panels needed to power Equipment.
On land, dust is separated from the soft rock formations by the forces of nature, wind, water, glaciers, volcanoes and meteors .However, for more than 4 billion years, courses of 3 9; water and glaciers in motion have probably only made a small contribution to the global dust reservoir on Mars. While meteor craters are a common feature of the sun's fourth planet, the fragments created by the impacts are usually larger than the fine particles that make up the Martian dust.
"How does Mars make so much dust, because none of these processes are active on Mars?" Said senior author Lujendra Ojha, a postdoctoral fellow in Lewis's lab. Although these factors played a role in the past, another factor is to blame for the vast expanses of dust surrounding Mars, he says.
Ojha and the scientific team have examined the chemical composition of the dust. The distant landers and rovers on the planet have all reported surprisingly similar data on dust. "The dust everywhere on the planet is enriched with sulfur and chlorine and it has a very clear sulfur-chlorine ratio," said Ojha
who studied the data collected by the Mars Odyssey satellite, orbiting the planet. since 2001. Ojha and her colleagues have been able to identify the CFP region as having an abundance of sulfur and chlorine, as well as a relation to the ratio of sulfur to chlorine in Mars dust.
Previous results suggest that the CFP had a volcanic origin. After 50% of the United States mainland area, the wind has eroded it, leaving behind an area that now looks like about 20%. Yet, it is the largest known volcanic deposit in our solar system.
The carved ridges known as yardangs are the remains of erosion. By calculating the amount of CFP lost over the last three billion years, scientists have been able to estimate the current amount of dust on Mars, enough to form an overall layer of 2 to 12 meters in thickness [19659005] by absorbing solar radiation, resulting in lower temperatures at ground level and higher temperatures in the atmosphere. This temperature contrast can create stronger winds, raising more dust from the surface.
While seasonal dust storms occur every Martian year (twice as long as a terrestrial year), dust storms can occur every 10 years or so.
"This simply explains, potentially, much of how Mars has arrived at its current state," said Lewis.
Learn more:
Image: Mars dust storm
More information:
Lujendra Ojha et al, The Formation of Medusae Fossae as the largest source of dust on Mars, Nature Communications (2018). DOI: 10.1038 / s41467-018-05291-5
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