Perseverance data suggests a strong river rushed down the delta in Jezero Crater
Click for original image.
Based on the images and geology so far gathered by the Mars rover Perseverance as it has climbed up onto the delta that flowed into Jezero Crater sometime in the far past, scientists now think a roaring river once flowed down that delta.
Years ago, scientists noticed a series of curving bands of layered rock within Jezero Crater that they dubbed “the curvilinear unit.” They could see these layers from space but are finally able to see them up close, thanks to Perseverance.
One location within the curvilinear unit, nicknamed “Skrinkle Haven,” is captured in one of the new Mastcam-Z mosaics [a section of which is posted to the right]. Scientists are sure the curved layers here were formed by powerfully flowing water, but Mastcam-Z’s detailed shots have left them debating what kind: a river such as the Mississippi, which winds snakelike across the landscape, or a braided river like Nebraska’s Platte, which forms small islands of sediment called sandbars.
When viewed from the ground, the curved layers appear arranged in rows that ripple out across the landscape. They could be the remnants of a river’s banks that shifted over time – or the remnants of sandbars that formed in the river. The layers were likely much taller in the past. Scientists suspect that after these piles of sediment turned to rock, they were sandblasted by wind over the eons and carved down to their present size.
The press release say nothing about glacial activity here, but I am willing to bet the scientists have considered this. As it requires a greater leap into the unknown, involving geological processes not yet understood on an alien planet, it is makes sense that they have put it aside at this point. I also am willing to bet that it will pop up again, with time and additional data.
