The Mars Express Mars rover of the European Space Agency has taken impressive images of the Holden basin on the Red planet - part of the key area in the search for life on Mars. Images and a deeper investigation into the area could help reveal how water once flowed through the surface of Mars.
A close-up image of the Holden basin - taken by Mars Express' high-resolution floating sound camera (HRSC) on April 24, 2022 - shows the geological characteristics of the former reservoir, which was nearly 150km wide in Holden C study.
The Holden basin forms part of a chain of canals and sinkholes covering the Uzboi-Ladon-Morava (ULM) flow system in Mars' southern Hemisphere. The system has become an important target for Mars orbiters such as Mars Express because scientists believe it may have sucked up 9% of the red planet's water.
Before Mars' water loss about 4 billion years ago, it is possible that Mars' atmosphere was harshly radiated by the sun, causing water "leakage" into space, and liquid water would flow through the canals leading to the Argyre Planitia plains.
From this 1,770km wide plain, up to 5.2km deep, water will flow through the Uzboi Vallis valley in the area now Holden Volcano C study.
The water will then be collected in the Holden basin before flowing through the Ladon Valles - a system of ancient river valleys leading to the 440km-wide Ladon basin.
The new image shows a distinct cape to the south of the basin and the walls of the basin sloped slightly to a depth of about 1,500m below the surrounding Mars surface.
Meanwhile, the northeastern part of the Holden basin shows where water will flow from this reservoir to Ladon Valles. Scars and rough terrain can be seen in the photo. It is likely that this terrain was created by the melting of ice below the Martian surface.
Where there is water, there is life
The European Space Agency (ESA) said that our experience with the planet shows that water and life go hand in hand. Scientists are looking to find out whether the same thing could be true for Mars billions of years ago.
Soil in Ladon Valles and Holden basin contains phyllosilicate - a mineral consisting of clay created by the interaction of rock and water related to the origin of life on Earth. Phyllosilicates in these regions present in sedimentary layers can act as a reaction center for organic molecules - the element that create life on the ground. That is why scientists are so interested in this area.
The mouth of Holden is likely to have formed after an ancient satellite collision when material pushed out from the collision fell back to the surface of the planet and filled the old Holden basin, which had been formed by a previous collision in the history of the planet.
Since there is no evidence of past water flowing through Holden C study, scientists believe it must have formed after the ULM system was depleted.
Because of its geological significance and the potential to preserve evidence of ancient life, Holden C study was selected as a launch site for both the Curiosity Mars and Perseverance spacecraft, but scientists later chose the Gale C study and the Jezero C study.
The Mars Express has been taking photos of Mars' surface and atmosphere from the Red planet's orbit since 2003, and is now ensuring that the area is thoroughly investigated.
Previous images of the Holden basin show that the mounds and troughs are made up of Martian winds, canyons and ancient rivers, as well as r allowed-go lakes and fossil volcanoes.
