'Once in a blue moon' is now

Roseburg, Ore. - Every few years, two full moons fall in the same calendar month.

This is known to astronomers as a "blue moon."

But the phrase also refers meteorologically to the lunar disc as seen through wildfire smoke, which skews the light to the blue spectrum.

Either way, the next "once in a blue moon" is Friday, Aug. 31, just before 7 a.m. PDT. The first full moon of the month happened Aug. 1.

Or maybe this year the moon is just mourning the loss of its first human friend, astronaut Neil Armstrong.

In any case, a blue moon is something rare - and something the weather may or may not obscure from sight.

SHOOT THE MOON: Share your blue moon photos