Bright blue-white noctilucent clouds danced over the town of Nykøbing Mors in Denmark just before dawn, just when this spectacular photo was taken. Night sky photographer Ruslan Merzlyakov ...

Delhi's sky transforms during monsoon, showcasing fluffy white clouds. Ideal spots for cloud-watching include Nizamuddin ...

During the last week of July and for a fair amount of August, there’s still time to spot some noctilucent cloud activity, as captured recently ...

The Color of Perception Sometimes, under direct sunlight, clouds will appear gray or dark gray against a blue sky or larger backdrop of white clouds. There are usually two reasons for this effect.

Blue light has a shorter wavelength, due to which it’s scattered more easily by the tiny molecules in the air. This scattering, known as Rayleigh scattering, is why we see a blue sky during the day.

We’ve all seen those white streaks trailing behind jets, creating stripes against the blue sky. The lines are called contrails, short for condensation trails, and they appear when water vapor ...

Night sky photographer Ruslan Merzlyakov captured bright blue-white noctilucent clouds dancing over Nykøbing Mors in Denmark just before dawn on July 1.