If we were to judge the supremacy of interplanetary rovers by the number of cameras they had, Nasa's Mars 2020 mission will be the undisputed king of the hill.
The rover has a grand total of 23 different "eyes" (opens in new tab), which will guide it as it performs its allocated tasks. From studying the atmosphere to keeping track of samples being processed inside the robot's belly, almost everything that the rover does will be visually recorded.
The reason for this abundance? Smartphones. Well, kind of. Camera technology has taken great leaps and bounds over the last decade or so, chiefly led by the smartphone revolution. We can now see more clearly than ever with tinier and tinier devices. On a space mission, where weight and bulk are at a premium, that makes a real difference.
"Camera technology keeps improving," said Justin Maki of JPL, Mars 2020's imaging scientist. "Each successive mission is able to utilize these improvements, with better performance and lower cost."
While the 17 cameras mounted on Nasa's Curiosity rover have allowed us to see the Red Planet in ways that we had never been able to before, their abilities will be substantially outstripped by Mars 2020's digital eyes.
Among the new rover's instruments will be engineering cameras (for driving and spotting obstacles) with a higher resolution and wider field of view than anything on Curiosity. "Our previous Navcams would snap multiple pictures and stitch them together," said Colin McKinney of JPL, product delivery manager for the new engineering cameras. "With the wider field of view, we get the same perspective in one shot."
It'll also have six cameras that will record the entry, descent and landing process, an improved version of Curiosity's Mastcam with a 3:1 zoom lens, a suite of cameras for studying Mars' clouds and atmosphere, and even a remote imager that can capture colour images.
The only problem will be getting all these pictures back to Earth.
"The limiting factor in most imaging systems is the telecommunications link," Maki said. "Cameras are capable of acquiring much more data than can be sent back to Earth."
Thankfully, the rudimentary interplanetary internet (opens in new tab)that exists between Earth and Mars lets us relay data through orbiting spacecraft, making it easier to send back data even if there's no direct line of sight to the rover.
You can find all the technical detail that you might want on Mars 2020's camera systems, including images of how they see the world, over on Nasa's website (opens in new tab).