Night Sky

Sky & Atmosphere

The night sky usually appears dark, but under certain conditions it can take on a bluish hue or glow. This overview explains the main physical causes, how to distinguish them, a...

Astronomy

The best time of year to see the Milky Way depends more than anything on dark skies, moonlight, and weather than on a single magic date. In each hemisphere, the galactic core ri...

Science & Nature

The question what are the phases of the moon begins with two simple facts: the Moon shines by reflected sunlight, and it orbits Earth about every 29.5 days. As the Moon moves, t...

Astronomy

At any given night, the brightest planet in Earth’s sky depends on each world’s position, phase, and distance. Planets appear as steady points of light that do not blink lik...