Nasa rover faces tough climb in search of Mars’s oldest mysteries

Jezero crater rim holds rocks that could provide insight into planet's ancient crust

The Perseverance rover arrived on Mars in 2021. EPA

A rover on Mars that has been hunting for signs of life is preparing for a trek to the rim of a 4 billion year-old crater, where it could uncover mysteries of the planet’s geologic history.

The Perseverance rover, a $2.7 billion Nasa mission, has been studying the floor and river delta of the Jezero crater for the past 30 months, collecting rocks that suggested the site once hosted a lake.

On Monday, its journey towards the crater rim begins at an elevation of 300 metres, a journey that will involve the rover climbing steep slopes of up to 23 degrees.

“Our samples are already an incredibly scientifically compelling collection, but the crater rim promises to provide even more samples that will have significant implications for our understanding of Martian geologic history,” said Eleni Ravanis, one of the crater rim campaign science leads.

“This is because we expect to investigate rocks from the most ancient crust of Mars.

“These rocks formed from a wealth of different processes, and some represent potentially habitable ancient environments that have never been examined up close before.”

The crater rim, which was formed by the powerful impact that created the Jezero crater billions of years ago, holds valuable information about Mars’s past.

Unlike the sedimentary rocks Perseverance studied on the crater floor, which were shaped by ancient water activity, the rim is expected to host materials that were ejected during the impact.

These materials could include rocks from deeper beneath Mars’s crust, offering a chance to study unaltered material that has not been shaped by surface processes like water erosion.

The rover has travelled 29km and collected 22 rocks so far, with more expected to be stored away as the mission continues.

Nasa is working with the European Space Agency to bring back the samples, in an ambitious return mission that will be finished by the end of this decade.

Scientists are excited about the rocks collected at the river delta, which are the first sedimentary rocks to be discovered on a planet other than Earth.

These rocks are formed by minerals and organic particles often found in water-rich environments.

Finding them on Mars suggests the planet used to have water, meaning the conditions could have existed to support microbial life.

“Among these rock cores are likely the oldest materials sampled from any known environment that was potentially habitable,” said Tanja Bosak, a geobiologist at the Massachusetts Institute of Technology in the US and a member of Perseverance’s science team.

“When we bring them back to Earth, they can tell us so much about when, why and for how long Mars contained liquid water and whether some organic, prebiotic and potentially even biological evolution may have taken place on that planet.”

The rover arrived on the planet in 2021 as part of the most expensive mission ever developed, which also included the Ingenuity helicopter.

Ingenuity made history as the first aircraft to achieve powered flight on another planet, and completed more than 70 successful flights.

Initially designed for just five flights, it exceeded expectations and continued to operate until its final flight on January 18 this year, when one of its rotor blades was damaged.