This new image from the High Resolution Stereo Camera (HRSC) onboard ESA’s Mars Express spacecraft shows Caralis Chaos, broken-down and dried-up remnants of a vast ancient Martian lake named Lake Eridania.
This image from ESA’s Mars Express shows Caralis Chaos, a Martian region where copious water is thought to have once existed in the form of an ancient lake known as Lake Eridania. Image credit: ESA / DLR / FU Berlin.
Lake Eridania once held more water than all other Martian lakes combined and covered an area of over a million km2.
The lake was larger than any known lake on Earth, containing enough water to fill the Caspian Sea nearly three times over.
It likely existed around 3.7 billion years ago, first as one large body of water and later as a series of smaller isolated lakes as it began to dry out.
Eventually Lake Eridania disappeared completely, along with the rest of the water on the Red Planet.
“The lower-left part of the frame features the remains of an old lakebed,” the Mars Express researchers said.
“The boundaries of this bed can be seen curving up and away from the center of the frame, skirting around the large central crater.”
“The old lakebed is now filled with lots of raised mounds, thought to have formed as ancient Martian winds swept dust across the planet.”
“This dust was later covered and altered by water, before drying out again and breaking apart.”
Alongside water, there are clear signs of volcanism at play in and around this region, known as Caralis Chaos.
“Two long cracks run horizontally through this image, cross-cutting both the aforementioned lakebed and the smoother ground to the top,” the scientists said.
“These are known as the Sirenum Fossae faults, and formed as Mars’ Tharsis region — home to the largest volcanoes in the Solar System — rose up and put immense stress on the Martian crust.”
“Volcanic stress is also to blame for the many wrinkle ridges found here.”
“These appear as wriggly lines weaving across the frame vertically.”
“Wrinkle ridges are common on volcanic plains, forming as new lava sheets are compressed while still soft and elastic, causing them to buckle and deform.”
“The impact craters here, created as space rocks collided with Mars, are also fascinating.”
