Is Pluto's Visible Light Intensity Equal to Earth's?

[Hobart]

Is the visible light on the surface of Pluto equivalent in intensity to what it is on Earth? That is, is 1 lux = 1 lux even though it takes light that much longer to get there from the sun? Or are images of distant objects in the solar system taken with longer exposures?

 

[russ_watters]

No, light intensity drops off as a square function of distance.

 

[Drakkith]

Lux is a unit of measurement. It doesn't change just by moving from the Earth to Pluto. However, the intensity of light does indeed drop off with distance from the Sun. Not because light has been traveling longer, but because it spreads out as it travels.