Blue Sunset

Blue Sunset


Sky on Mars is red, while its sunsets are blue.


share Share

The light from the Sun scatters based on what's in the atmosphere. Sunlight comprises light of many different wavelengths, and molecules and dust particles only interact with specific waves. The scattering of light by these particles is key to the color that we see.

The atmosphere on Mars is very tenuous, its pressure is equivalent to about 1 percent of Earth's. It is made of carbon dioxide and has a lot of dust. This fine dust tends to scatter red light so that the sky appears reddish, which lets the blue light through.


How Many Galaxies Are There?

The cosmos contains approximately 100 - 200 billion galaxies.

Read More
Dark Energy

Humans can only see about 4% of the matter in the Universe.

Read More
Mercury and Venus

The only two planets in our solar system that do not have moons are Mercury and Venus.

Read More
Our Sun's Orbit

The sun orbits around the Milky Way at a speed of about 220 km (140 miles) per second.

Read More