photo #4226151

This is the dwarf planet Pluto, spotted in 2015 by NASA’s New Horizons spacecraft from a distance of just 120,000 miles (200,000 km). This view was from the night side of the dwarf planet, so its surface is in complete darkness but its hazy atmosphere catches the sunlight and glows with a blueish hue that shows what looks to be a layered structure. The haze is likely a cocktail of hydrocarbons produced by the sunlight reacting with methane and other atmospheric gases. The smog of hydrocarbons seems to have settled into horizontal striations and appears to scatter more of the shorter blue-looking wavelengths of light to create this bluish glow. The effect is likely similar to the way Earth’s atmosphere produces a blue sky during the day. Pluto’s ghostly layers of haze extend to altitudes of more than 120 miles (200 km), which is twice the height of Earth’s atmosphere.