ECLIPSES OF THE MOON The phenomena attending eclipses of the moon are not of great astrophysical interest nowadays. Owing to the earth's atmosphere there is never complete darkening of the lunar surface. Even at mid-eclipse there is sufficient light refracted to make it visible as of a dull ruddy hue. The reddening is due to the absorption of the blue rays in our atmosphere. The brightness of the moon in eclipse varies considerably presumably owing to the variability of our atmospheric conditions, cloudiness and suspended dust, etc.