Images from Mars reveal how water helped shape the Red Planet landscape billions of years ago and provide clues that will guide the search for evidence of ancient life, a study said Thursday.
In February, NASA’s Perseverance rover landed in the Jezero crater, where scientists suspect that a long-lost river once fed a lake and deposited sediment in a fan-shaped delta visible from space.
The study in Science analyzed high-resolution images taken with endurance of the rocks that were once the banks of the delta.
Layers within the rocks reveal how its formation took place.
NASA astrobiologist Amy Williams and her team in Florida found similarities between features of the rocks seen from the crater floor and patterns in Earth’s river deltas.
The shape of the bottom three layers showed early presence and stable water flow, indicating that Mars was “hot and humid enough to support a hydrological cycle” about 3.7 billion years ago, the study says.
The upper and newest layers have boulders measuring more than a meter in diameter scattered around, probably carried there by violent floods.
But it is the fine-grained sediment of the base layer that is likely to be the target of sampling for signs of long-extinct life — if it existed — on Mars.
The results will help scientists figure out where to send the rover for earth and rocks that may contain precious “biosignatures” of suspected Mars life forms.
“From orbit images, we knew it had to be water that formed the delta,” Williams said in a press release.
“But having those pictures is like reading a book instead of just looking at the cover.”
Finding out if life may have existed on Mars is Perseverence’s most important mission, a project that took decades and cost billions of dollars to develop.
Over the course of several years, the multi-tasking rover will collect 30 rock and soil samples in sealed tubes that will eventually be sent back to Earth sometime in the 2030s for laboratory analysis.
Last month, mission researchers announced that Perseverance had collected two rock samples in Jezero that showed signs of being in contact with groundwater for a long period of time.
Their hope is that at some point the specimens could have hosted ancient microbial life, whose evidence could have been captured by salt minerals.
Knowing that Mars could once have contained life would be one of the most “profound” discoveries mankind has ever made, Williams said.
She also expressed wonder at having a window to an ancient river system on another planet.
“It’s really eye-opening to see something no one on Earth has ever seen before,” she said.
Endurance landed on February 18, and the study looks at long-distance images it took during the first three months on Mars.
Approximately the size of an SUV, it is equipped with 19 cameras, a two-meter (seven-foot) long robotic arm, two microphones and a range of advanced instruments.
One of them is called the SuperCam, a tool that laser-zips stones remotely to study their steam with a device that reveals their chemical composition.
It took seven months for endurance to travel from Earth to Mars with its sister vessel Ingenuity, a tiny helicopter whose rotors must rotate five times faster than Earth’s versions to get a lift in the much less dense atmosphere.
The plan is for the rover to cross the delta, then the old lake shore and finally explore the edges of the crater.