2400 rpm, or about the same speed as the propeller of a prop airplane. A shutter speed of around 1/4000s should be enough to stop the motion quite effectively. The shadow's directly underneath so it seems to be local noon and there should be plenty of light (I guess the "sunny 16" rule of thumb[1] on Mars is more like "sunny 13" or "sunny 11" though :D)

However, I'm curious about the lack of any rolling shutter effect[2]; I wonder if the camera has a proper mechanical shutter rather than an electronic one, or even a global shutter?

[1] https://en.wikipedia.org/wiki/Sunny_16_rule

[2] https://en.wikipedia.org/wiki/Rolling_shutter

It has been a long time since I studied this but I recall something about black and white CCDs having shorter shutter/exposure times required, for a given luminance and aperture... The downward facing cam may also be global shutter and not rolling shutter?