Hundreds of millions of Americans will have the chance in March to see the first total lunar eclipse in nearly three years.

Understanding why the sky is blue reveals a story of light, molecules, and the interplay of colors in our world. To uncover the mystery of the sky’s blue hue, we first need to understand sunlight.

"We are literally mapping the entire celestial sky in 102 infrared colors for the first time in humanity's history." ...

Ever wonder why the sky is blue, vs. say red, orange or purple? An effect called Rayleigh Scattering is part of the reason we see only blue, despite it all starting with a rainbow of colors.

The moon's ascending node (the point in the sky where its orbit crosses the ecliptic from south to north) is moving westward around the ecliptic once in 18.61 years (6,798 days). This drift carries ...