Mars’ surface area is 145 million square kilometres. Now a new technique can scrutinise that surface to five-centimetre resolution, and cover way more ground than even the rovers.

Planetary scientists may soon no longer need a rover to clearly see details of the Martian landscape. "Stacking" multiple photos snapped by a camera orbiting thousands of kilometres above can pick out objects on the surface just five centimetres wide, including tracks left by a rover.

University College London’s Yu Tao and Jan-Peter Muller published the technique, dubbed Gotcha-PDE-TV, in Planetary and Space Science.

The duo says it can be used to pick safe landing spots and track down failed missions, and will allow scientists to explore more terrain than is possible with a single rover.

Original HiRISE image on the upper panel at 25-centimetre resolution. The lower panel is the super-resolution restoration (SRR) of the same area, but constructed from six HiRISE images at 6.25-centimetre resolution. The SRR image shows the John Klein drill-spot on the patch of flat outcrop on the Curiosity rover’s traverse. – Tao and Muller, 2016

"We now have the equivalent of drone-eye vision anywhere on the surface of Mars where there are enough clear repeat pictures,” Muller says.

“It allows us to see objects in much sharper focus from orbit than ever before and the picture quality is comparable to that obtained from landers.

"As more pictures are collected, we will see increasing evidence of the kind we have only seen from the three successful rover missions to date. This will be a game-changer and the start of a new era in planetary exploration."

Original image (upper panel) and super-resolution restoration from five input images (lower). – Tao and Muller, 2016

Cameras orbiting Mars are limited to a resolution of around 25 centimetres. But by stacking and matching pictures of the same area taken at different angles, Gotcha-PDE-TV super-resolution restoration can pick out objects as small as five centimetres.

In these images, Tao and Muller stacked between four and eight images of Mars’ surface taken by the High Resolution Imaging Science Experiment (HiRISE) telescopic camera on the Mars Reconnaissance Orbiter, which orbits the red planet at around 24,000 kilometres.

Zoomed-in original HiRISE images (upper panels) of the MER-A Spirit Home Plate region and super-resolution restoration from eight HiRISE images below. Note the MER-A rover tracks in the bottom right panel. – Tao and Muller, 2016

“In the future, we will be able to recreate rover-scale images anywhere on the surface of Mars and other planets from repeat image stacks,” Tao says.

He and Muller plan to explore more of Mars using the technique to see what other relics of space exploration they can find.