Curiosity's record 1 km climb on Mount Sharp leaves the yardangs a 2027 target

Mount Sharp is 5 km tall ^[5], so the 1 km of elevation Curiosity has now reached is about a fifth of the mountain's stated height ^[14]. NASA calls the gain the most ever climbed on Mars ^[4]. The yardangs are still ahead. Scientists hope to reach the base of that layer sometime in 2027 ^[11], about 13 years after the climb began ^[15].

The new panorama is a picture taken from a distance, and the processing was a deliberate choice. The published version shows blue hues in the foreground. Unlike most Mastcam images, it was processed without white balancing, to preserve the early-morning appearance ^[3]. Mastcam was built by Malin Space Science Systems in San Diego, which also operates it ^[12]. NASA says the result is the most detailed view yet of the yardangs ^[1].

"The yardang layer looks out of place. It's the wrong color, the layers tilt at an odd angle, and it almost appears plastered on," said Ashwin Vasavada, Curiosity project scientist at NASA's Jet Propulsion Laboratory ^[6]. He went on: "But that's what makes it exciting to reach. No one is sure exactly what created this layer, but one idea is it may be ash deposited by ancient volcanic eruptions" ^[7].

The ash idea has to fit what the mountain has already shown. Each of Mount Sharp's layers records a distinct period of Mars' history. Studying them has told scientists about lakes and streams that covered this region billions of years ago, then dried up and left salty minerals behind ^[8]. The next year or so of driving runs through layers enriched with sulfates and carbonates, both signs of ancient drying at the surface ^[13]. At the base of the yardangs, the robotic arm is to collect what NASA calls "one-of-a-kind data" ^[11]. The release does not say which measurements would tell volcanic ash apart from other sediment.

In my view the arm data at the yardang base are the result to wait for. Until they arrive, volcanic ash is, in Vasavada's words, "one idea" ^[7].