Why so blue? 🔵 Neptune, the eighth planet from the Sun, sometimes referred to as “the other blue planet” has for centuries captivated astronomers with its distinctive blue hue. The predominant blue color of the planet is a result of the absorption of red and infrared light by Neptune's methane-rich atmosphere. Clouds that escape high above the planet’s methane atmosphere often appear white in color, while the very highest of clouds tend to be visible in shades of yellow-red. This image was one of the first ever taken by a spacecraft of Neptune. Captured by the Voyager 2 spacecraft, the first (and only) spacecraft to observe the planet. It passed over Neptune’s north pole on Aug. 31, 1989. It took the spacecraft 12 years to reach the planet, and Neptune was Voyager 2’s final target after observing Jupiter, Saturn, and Uranus. Since passing Neptune, Voyager 2 has continued its journey onward through the edge of our solar system, and in 2018, became the second spacecraft to reach interstellar space. Image Description: Neptune’s horizon as pictured by the Voyager 2 spacecraft. Neptune is visible as a light-blue crescent with both points facing downwards at the center of the image. Near the top of the crescent are white wispy clouds of methane high in the atmosphere reminiscent of a feather in the wind. The bottom portion of Neptune below the horizon is a sapphire blue. The background of the image is the same sapphire blue on the left of the image and slowly fades into the dark black of space as it approaches the right of the image. Credit: NASA/JPL-Caltech/Kevin M. Gill #NASA #Space #Neptune #SolarSystem #Astrophotography #OtherBluePlanet #BigBluePlanet #Voyager #Blue