new images from high resolution stereo camera (HRSC) On ESA's Mars Express spacecraft It shows the terrain surrounding Mars's permanent ice cap at its north pole.
This image from ESA's Mars Express shows an area close to Mars' north pole. This image consists of data collected by Mars Express' High Resolution Stereo Camera (HRSC) on April 14, 2023. Image credit: ESA / DLR / FU Berlin.
Mars' permanent north polar ice cap is a stack of water ice and dust layers up to 3 km thick and approximately 1,000 km in diameter.
These are divided into four stacked “packets” of different thicknesses, which are further composed of finer layers.
These layers contain information about the climate going back millions of years in Mars' history.
The deposits were formed by precipitation of dust and water ice in the atmosphere and by direct frost formation.
These consist primarily of water ice, with fine dust deposits accounting for 10-15% of the total.
These likely reflect changes in Mars' orbit and the tilt of Mars' axis of rotation, which is much more unstable than Earth's orientation.
It changes in several cycles with periods ranging from thousands of years to millions of years.
Changes in solar radiation cause significant changes in climate, especially in the polar regions. The Arctic ice sheet is currently thought to be growing.
“The landforms surrounding Mars' north pole, known as pranum boriumfascinating,” said a member of the Mars Express team.
“The poles themselves are covered with a layer of fine dust and water ice. These stack up several kilometers thick and extend for about 1,000 kilometers.”
“Most of this material is not visible here, but you can see the beginning of the planum boreum on the right side of the frame. There are some subtle wrinkles that indicate where layers of material are starting to accumulate.”
“The ground has also become more distinctly stepped, as most clearly seen in the topographical map of the area below.”
“The lowest elevation areas are blue/green, and the highest elevation areas are red/white/brown.”
“These layers formed as a mixture of dust, water ice, and frost that accumulated on the Martian ground over a long period of time.”
“Each layer contains valuable information about Mars' history, telling us how the planet's climate has changed over the past millions of years.”
“During the Martian winter, a thin cap of carbon dioxide ice several meters thick rests on top of that layer. This cap completely disappears into the atmosphere each year during the Martian summer.”
The left side of the image is dominated by a vast strip of undulating sand dunes, extending over 150 km within this frame alone.
This wrinkled, turbulent appearance is very different from the smoother, more primitive terrain seen on the right.
This smooth area shows no obvious signs of erosion and has been spared from being hit by rocks from space. This indicates that the surface is very young and is probably getting younger every year.
“Between these two extremes are two semicircular cliffs, the larger of which is approximately 20 km wide,” the researchers said.
“Within the curves of these cliffs are frost-covered dunes.”
“The sheer scale of the cliffs is evident from the dark shadow they cast on the ground below. Sheer walls of ice can reach up to a kilometer in height.”
“These two cliffs are located in what's called a polar trough, a landform formed when wind pushes and wears down the earth's surface.”
“These appear as wavy ridges in the landscape and are common in this region, creating the characteristic spiral pattern of the polar plateau.”
Source: www.sci.news
