NASA's 2020 Mars rover to have 23 'eyes'

NASA's Mars 2020 mission will have more cameras than any rover before it - a grand total of 23 - to create sweeping panoramas, reveal obstacles and study the atmosphere of the red planet.

These "eyes" will provide dramatic views during the rover's descent to Mars and be the first to capture images of a parachute as it opens on another planet, the US space agency said.

There will even be a camera inside the rover's body, which will study samples as they are stored and left on the surface for collection by a future mission, according to NASA.

The cameras on 2020 will include more colour and three- dimensional (3D) imaging than on Curiosity, said Jim Bell of Arizona State University, principal investigator for 2020's Mastcam-Z.

The "Z" stands for "zoom," which will be added to an improved version of Curiosity's high-definition Mastcam, the rover's main eyes.

Mastcam-Z's stereoscopic cameras can support more 3D images, which are ideal for examining geologic features and scouting potential samples from long distances away.

Features like erosion and soil textures can be spotted at the length of a soccer field.

Documenting details like these is important: They could reveal geologic clues and serve as "field notes" to contextualise samples for future scientists.

"Routinely using 3D images at high resolution could pay off in a big way. They are useful for both long-range and near-field science targets," Bell said.

When NASA's Mars Pathfinder touched down in 1997, it had five cameras: two on a mast that popped up from the lander, and three on NASA's first rover, Sojourner.

They represent a steady progression since Pathfinder: after that mission, the Spirit and Opportunity rovers were designed with 10 cameras each, including on their landers; Mars Science Laboratory's Curiosity rover has 17.

"Camera technology keeps improving," said Justin Maki of NASA's Jet Propulsion Laboratory (JPL) in California.

"Each successive mission is able to utilise these improvements, with better performance and lower cost," said Maki, Mars 2020's imaging scientist.

The Spirit, Opportunity and Curiosity rovers were all designed with engineering cameras for planning drives (Navcams) and avoiding hazards (Hazcams). These produced 1- megapixel images in black and white.

On the new rover, the engineering cameras have been upgraded to acquire high-resolution, 20-megapixel colour images, NASA said.

Their lenses will also have a wider field of view. That is critical for the 2020 mission, which will try to maximise the time spent doing science and collecting samples, it said.