APOD
Astronomy Picture of the Day
Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
Crescent Neptune and Triton
Explanation: Gliding silently through the outer Solar System , the Voyager 2 spacecraft camera captured Neptune and Triton together in crescent phase. The elegant picture of the ice-giant planet and its cloudy moon was taken from behind just after closest approach in 1989. It could not have been taken from Earth because Neptune never shows a crescent phase to sunward Earth. The unusual vantage point also robs Neptune of its familiar blue hue , as sunlight seen from here is scattered forward, and so is reddened like the setting Sun . Neptune is smaller but more massive than Uranus , has several dark rings , and emits more light than it receives from the Sun.
| Date | July 25, 2021 |
|---|---|
| Credit | Image Credit: NASA , Voyager 2 |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |



