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Part of the Medusae Fossae Formation on Mars showing the effect of billions of years of erosion. The image comes from a camera on board the Mars Reconnaissance Orbiter. Image via NASA / JPL / U. Arizona
Mars is currently experiencing a global dust storm. Seasonal dust storms occur every Martian year, but global dust storms like today's occur every 10 years or so.
As in the movie "The Martian", where a strange dust storm an astronaut played by actor Matt Damon, the current dust storm on Mars causes serious problems for real missions – for example, rover Opportunity, which had to suspend its scientific operations. The fine and powdery substance can get into expensive instruments and obscure the solar panels needed to power the equipment.
So where does all this dust come from? A new study indicates that the dust that covers much of the Martian surface comes largely from a unique geological formation 1,000 kilometers long (600 miles long) near the planet's equator . The study, published July 20, 2018, in the peer-reviewed journal Nature Communications found a chemical match between dust in the Martian atmosphere and the surface, called the Formation of Medusae Fossae.
Side-by-side films show how dust has enveloped the red planet, thanks to the Mars Color Imager (MARCI) camera embarked on NASA's Mars Reconnaissance Orbiter (MRO). The May view shows the Valles Marineris chasms (left), the center of Meridiani, an autumn dust storm at Acidalia (top) and the polar cap in early spring (below). The July view shows the same regions, but most of the surface is obscured by the cloud of dust and haze surrounding the planet.
Kevin Lewis, co-author of the study, is Assistant Professor of Earth and Planets. Hopkins University. Lewis said in a statement:
Mars would not be so dusty if it were from this huge deposit that gradually erodes over time and pollutes the planet, essentially.
The team studied data captured by the Mars Odyssey spacecraft, orbiting the planet since 2001. They also studied the chemical composition of Mars dust. The distant landers and rovers on the planet have all reported surprisingly similar data on dust. Lujendra Ojha, the main author of the study, said:
The dust everywhere on the planet is enriched with sulfur and chlorine and it has this very distinct sulfur-chlorine ratio.
Researchers were able to locate the Medusae Fossae Formation The region has an abundance of sulfur and chlorine, as well as a proportion of sulfur compared to chlorine in the dust of Mars.
On land, dust is separated from soft rock formations by the forces of nature, including wind, water and glaciers. , volcanoes and meteor impacts. But on Mars, for more than 4 billion years, say the researchers, these forces have only made a small contribution to the planetary dust reservoir of the planet. Ojha also said:
How does Mars make so much dust because none of these processes is active on Mars?
Previous discoveries suggest that the Medusae Fossae Formation had a volcanic origin. Once the size of half of the continental United States, the wind has eroded it, leaving behind an area that now looks like about 20%. Yet, it is the largest known volcanic deposit of our solar system.
By calculating how much of the Medusae Fossae Formation was lost over the 3 billion years, scientists could estimate the current amount of dust on Mars. an overall layer of 7 to 40 feet (2 to 12 meters) in thickness
Bottom line: A new study indicates that the dust that covers much of the surface of Mars comes largely from a single kilometer long (600 miles) -long) geological formation near the planet's equator called the Medusae Fossae Formation.
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