Tuesday will see the six-wheeled robot begin the climb up an ancient delta feature in the crater where it landed.

It will roll uphill, stopping every so often to examine rocks that look to have the best chance of retaining evidence of past life on the planet.

"The delta in Jezero Crater is the main astrobiology target of Perseverance," said deputy project scientist, Dr Katie Stack Morgan.

"These are the rocks that we think likely have the highest potential for containing signs of ancient life and can also tell us about the climate of Mars and how this has evolved over time," she told BBC News.

A delta is a structure built up from the silt and sand dumped by a river as it enters a wider body of water.

"Rivers that flow into a delta will bring nutrients, which are helpful for life, obviously; and then the fine-grained sediment that is brought and laid down at a high rate in a delta is good for preservation," explained mission scientist Prof Sanjeev Gupta from Imperial College London, UK.

This is a gentle incline that will take the robot to an elevation of a few tens of metres above the crater floor.

"We will learn about the chemistry of this ancient lake, whether its waters were acidic or neutral, whether it was a habitable environment and what kind of life it might have supported.".

To be clear, no-one knows if life ever got started on Mars, but, if it did, the three or four rocks Perseverance chooses to drill and cache on the way back down to the crater floor could be the ones to tell us.

"The claim that there is microscopic life on another planet in our Solar System is an enormous claim.

This depot will comprise not just those rocks gathered during the Hawksbill descent but four samples collected in previous months out on the crater floor.

After it has put down its first rock stash, it will drive back up Hawksbill Gap to the very top of the delta and beyond, to visit rocks that look like they could be the remnants of the shoreline to the ancient Jezero lake?

These deposits are made of carbonate minerals, and, again, look to have formed in a setting conducive to the recording of past life - if ever it existed.