Tycho and Copernicus: Lunar Ray Craters
9.08.2001

Dazzling in binoculars or a small telescope, the Moon is pocked with impact craters. During partial lunar phases, the craters along the terminator are cast in dramatic relief by strong shadows. But when the Moon is full some craters seem to sprout systems of bright radial lines or rays.

The Flash Spectrum of the Sun
15.11.2013

In a flash, the visible spectrum of the Sun changed from absorption to emission on November 3rd, during the brief total phase of a solar eclipse. That fleeting moment is captured by telephoto lens and diffraction grating in this well-timed image from clearing skies over Gabon in equatorial Africa.

Surreal Moon
14.08.2014

Big, bright, and beautiful, a Full Moon near perigee, the closest point in its elliptical orbit around our fair planet, rose on August 10. This remarkable picture records the scene with a dreamlike quality from the east coast of the United States.

The Extraordinary Spiral in LL Pegasi
11.12.2016

What created the strange spiral structure on the left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.

APOD: 2024 February 13 Б A January Wolf Moon
13.02.2024

Did you see the full moon last month? During every month, on average, a full moon occurs in the skies over planet Earth. This is because the Moon takes a month to complete another...

Eclipse in African Skies
22.06.2001

Yesterday, for a brief few minutes, a total eclipse of the Sun brought darkness to southern Africa's daytime skies. During this first total solar eclipse of the third millennium webcast sites were swamped, but sun-watchers along the eclipse path enjoyed clear weather and reported fantastic views.

The Climber and the Eclipse
6.09.2017

What should you do if your rock climbing picture is photobombed by a total eclipse of the Sun? Rejoice -- because your planning paid off. After months of considering different venues, and a week...

Accretion Disk Binary System
19.12.1999

Our Sun is unusual in that it is alone - most stars occur in multiple or binary systems. In a binary system, the higher mass star will evolve faster and will eventually become a compact object - either a white dwarf star, a neutron star, or black hole.

An Extraordinary Spiral from LL Pegasi
14.09.2010

What created the strange spiral structure on the left? No one is sure, although it is likely related to a star in a binary star system entering the planetary nebula phase, when its outer atmosphere is ejected.

Full Moon, Full Mars
15.12.2022

On December 8 a full Moon and a full Mars were close, both bright and opposite the Sun in planet Earth's sky. In fact Mars was occulted, passing behind the Moon when viewed from some locations across Europe and North America.