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.

2022 April 21
See Explanation. Clicking on the picture will download
the highest resolution version available.

Apollo 16 Moon Panorama
Image Credit: Apollo 16, NASA; Panorama Assembly: Mike Constantine

Explanation: Fifty years ago, April 20, 1972, Apollo 16's lunar module Orion touched down on the Moon's near side in the south-central Descartes Highlands. While astronaut Ken Mattingly orbited overhead in Casper the friendly command and service module the Orion brought John Young and Charles Duke to the lunar surface. The pair would spend nearly three days on the Moon. Constructed from images (AS16-117-18814 to AS16-117-18820) taken near the end of their third and final surface excursion this panoramic view puts the lunar module in the distance toward the left. Their electric lunar roving vehicle in the foreground, Duke is operating the camera while Young aims the high gain communications antenna skyward, toward planet Earth.

Celebrate: Earth Day
Tomorrow's picture: our fair planet < | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.


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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.

2022 April 22
See Explanation. Clicking on the picture will download
the highest resolution version available.

Planet Earth at Twilight
Image Credit: ISS Expedition 2 Crew, Gateway to Astronaut Photography of Earth, NASA

Explanation: No sudden, sharp boundary marks the passage of day into night in this gorgeous view of ocean and clouds over our fair planet Earth. Instead, the shadow line or terminator is diffuse and shows the gradual transition to darkness we experience as twilight. With the Sun illuminating the scene from the right, the cloud tops reflect gently reddened sunlight filtered through the dusty troposphere, the lowest layer of the planet's nurturing atmosphere. A clear high altitude layer, visible along the dayside's upper edge, scatters blue sunlight and fades into the blackness of space. This picture was taken in June of 2001 from the International Space Station orbiting at an altitude of 211 nautical miles. Of course from home, you can check out the Earth Now.

Celebrate: Today is Earth Day
Tomorrow's picture: Messier 104

< | Archive | Submissions | Index | Search | Calendar | RSS | Education | About APOD | Discuss | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (UMCP)
NASA Official: Phillip Newman Specific rights apply.
NASA Web Privacy Policy and Important Notices
A service of: ASD at NASA / GSFC
& Michigan Tech. U.