# How much dimmer does the Sun appear from Pluto than from the Earth?

The apparent brightness of the Sun from any orbiting object varies, because the orbits are elliptical and so the distances vary. But on average Pluto is about $39.5$ times as far from the Sun as Earth is.
$\left\{\text{Brightness on Earth"}/{"Brightness on Pluto}\right\} = {39.5}^{2} = 1560$.