[paulmooreparks]

In the paragraph right above the one you reference:

> Beneath that ice, the light sensors recorded an astronomically small number of photons: an upper range of 0.04 micromoles per square meter per second, a number very close to the theoretical minimum amount of light that photosynthesis can run on. The actual amount of light was probably lower.

[magicalhippo]

It's not a direct conversion it seems, but assuming daylight then 0.04 umol/s/m^2 should be around 2 lux.

I was curious how this compared to being on Pluto, but apparently Pluto gets a lot more sunlight than I imagined[1]:

So at high noon on Pluto you’d get at least 60 lux of sunlight.

Civil twilight is roughly enough light to read by, and that’s 3.4 lux. Moonlight is less than 0.3 lux.

60 lux would be comparable to indoor lighting in a hall or stairway.

[1]: https://www.johndcook.com/blog/2018/03/09/could-you-read-on-...

[HPsquared]

Direct sunlight on Earth can be 100,000 lux, for comparison.