The photos of Pluto from New Horizons are truly beautiful.

But considering that Pluto is so far away from its nearest start - our Sun - how is it so well lit up?

Did the New Horizons have a massive flash mounted on its camera to illuminate the planet or is there just a lot of ambient light in space?

I'm really curious.


  • 6
    $\begingroup$ A flashbulb suitable for lighting up Pluto would bear more than a passing resemblance to Tsar Bomba $\endgroup$
    – Mark
    Commented Jul 27, 2015 at 6:16
  • 2
    $\begingroup$ A combination of sensitive detectors, aperture and exposure. Also a lot of post processing (it is a composite from more than one sensor) $\endgroup$ Commented Jul 27, 2015 at 6:44

1 Answer 1


It's brighter on Pluto than you think.

NASA developed a tool called Pluto time, which tells you when at your place the ambient light conditions are similar to the ones on Pluto. This occurs when the Sun is only 2° below the horizon! That's quite shortly after sunset, and considerably before the end of civil twilight, which is when it's 6° below.

All of these photos were taken at local "Pluto time":

Pluto time
Pluto time, according to NASA. Source: NASA

To answer your question: all it takes is a slightly longer exposure time / larger aperture / higher gain (what photographers may call ISO) than taking photos closer to the Sun. It's easily bright enough for outdoor activities (except perhaps on a cloudy evening and/or in a dense forest, but neither should be common beyond the orbit of Neptune), so have fun glacier hiking on Pluto!


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