by Sign up for CNN’s Wonder Theory science newsletter. Explore the universe with news on exciting discoveries, scientific advances and more.
The Endurance rover has begun its long climb up the steep rim of Jezero Crater in search of some of the oldest rocks on Mars – and the potential for environments that may once have hosted life on the red planet.
Landing in Jezero Crater 3 1⁄2 years ago, the robotic explorer explored the site of an ancient lake and river delta and collected many rock samples. But his latest scientific expedition could rewrite the way astronomers understand Mars.
“Persistence has completed four science campaigns, collected 22 rock cores, and traveled more than 18 unpaved miles (29 kilometers),” said Art Thompson, Persistence project manager at NASA’s Jet Propulsion Laboratory in Pasadena, California, in statement. “As we begin the Crater Rim Campaign, our rover is in excellent condition, and the team is excited to see what’s on the roof of this place.”
The rover will use its auto-navigation capability, which allows Endurance to function as a self-driving car, to follow a route planned by the vehicle’s engineers. The route will enable the rover to avoid hazards on the challenging climb. Persistence will gain about 1,000 feet (300 meters) in altitude when it hits the rim towards the end of 2024.
This ascent is something that scientists have been looking forward to for years, long before a permanent landing on Mars.
About 4 billion years ago, something of some kind crashed into Mars and created Jezero Crater, and the impact sent up huge blocks of rock that were trapped in the rim of the crater.
“We should be able to access and sample some of the oldest rocks on Mars,” said Briony Horgan, co-investigator of the Endurance rover mission and professor of planetary science at Purdue University in West Lafayette, Indiana.
“We think these include everything from ancient sedimentary rocks that may have preserved the earliest habitable environments on Mars, to the planet’s building blocks that were the earliest crust to dawn on the solar system.”
The crater rim will provide a window into the earliest period of Mars’ history — and may reveal evidence of hot springs that could have supported ancient microbial life, Horgan said.
Turning back Martian time
The impact that created Jezero Crater also generated a lot of heat, partly from the energy of the object that crashed into Mars. Some of the heat also came from warmer rock beneath the Martian surface, as the planet was still cooling after forming half a billion years earlier. The impact sent those rocks up from beneath the Martian surface.
Had groundwater or surface water been present on Mars at the time, which scientists believe would likely have led to hydrothermal systems, said Ken Farley, Persistence project scientist and professor of geochemistry at the California Institute of Technology.
With hydrothermal systems, hot water likely seeped through cracks in rocks and may have created the right environment for microbial life to thrive.
So far, Persistence has investigated the location of the ancient lake bed and river delta, where life could have existed. The location of the crater rim of Pico Turquino, as the hydrothermal rocks are known, provides another, different possibility.
“In the scheme of the overall objectives of the mission, the demand for evidence of possible life on Mars is very high here, so we want to investigate as many potentially habitable environments as Mars will offer us,” said Farley.
The scientific team is also keen to reach Witch Hazel Hill, a large outcrop of black-and-white layered rock that stretches for hundreds of meters. These rock layers may preserve information about the climate of Mars billions of years ago. The rover should arrive there in six to nine months.
Plate tectonics and other erosional processes have destroyed some of the earliest rocks on Earth, but ancient rocks encoded with the history of Mars remain on the red planet.
The solar system was formed 4.55 billion years ago, and the science team hopes to find and study Martian rocks that are 4.2 billion years old, Farley said.
Going up the crater
During the long drive up the crater wall, Perseverance could encounter slopes of almost 23 degrees. Normally, the team avoids any way the rover tilts more than 30 degrees. But the rover is well prepared for the climb and is in no danger, Farley said.
“Climb up the rim of the crater, although it would be a bit of an arduous journey for us humans, from a rover point of view it will not really be that big to deal with,” said Steven Lee, Persistence deputy project manager.
But the rover’s rate of progress could be slow if it feels its wheels slipping on the Martian terrain or encounters large boulders during the climb.
Endurance can watch the terrain while driving, and if its wheels slip too much, the rover will stop and say “call Mom home, wait to be told what to do and we’ll get it out on the ground ,” Lee said.
The rover remains in excellent condition, and “there’s no telling that we can’t continue to operate this vehicle for many more years,” Lee said.
By the time the rover climbs to the top of the rim, it will have traveled thousands of kilometers more and captured tons of new images for the mission team to analyze.
“It’s a unique perspective for those of us who go to work on the project every day,” Lee said. ” You soon understand Mars as a place. My memories of Perseverance crossings are very similar to walking. I can imagine what Mars looks like from the landing site all the way to where we are today.”
And the rover’s perspective above the 28-mile-wide (45-kilometer-wide) crater will provide some beautiful views.
“We’re sure to get great views looking back where we came from in Jezero and out on the plains beyond,” Horgan said.
It will be the biggest challenge for the scientific team as they decide which rocks to study as well as which ones to collect samples from. With so many interesting rock piles the size of a school bus, the team will have to learn as much as possible while keeping the rover moving.
“We’re going to have all this stuff thrown right in front of us,” Farley said, “so I think it’s going to be a very different kind of exploration.”
The team expects Persistence to spend at least a few years beyond the crater’s edge collecting samples.
Meanwhile, the question of how those samples, as well as those collected inside the crater, will return to Earth as NASA reevaluates the Mars Sample Return program. The agency is evaluating various proposals and is expected to announce a decision in the fall.
The decision could determine how far and how far the rover drives because the vehicle could be responsible for delivering samples to a spacecraft to bring back to Earth.
“This part of the mission is essential to creating a sample collection that will be the collection of everyone’s dreams,” Farley said. “For now, all we have to do is continue our investigation on the edge of the crater. And then when the time comes, we will do whatever we need to do to support the Sample Mars Return.”
For more CNN news and newsletters create an account at CNN.com
