35 sts
Word of the Day for Wednesday, June 20, 2012

noctilucent \nok-tuh-LOO-suhnt\, adjective:

Visible during the short night of the summer.

So Sax would sit on the Western sea cliff, rapt through the setting of the sun, then stay through the hour of twilight, watching the sky colors change as the sun’s shadow rose up, until all the sky was black; and then sometimes there would appear noctilucent clouds, thirty kilometers above the planet, broad streaks gleaming like abalone shells.
-- Kim Stanley Robinson, Blue Mars