Alphonsus and Arzachel
17.07.2021

Point your telescope at tonight's first quarter Moon. Along the terminator, the shadow line between night and day, you might find these two large craters staring back at you with an owlish gaze. Alphonsus (left) and Arzachel are ancient impact craters on the north eastern shores of Mare Nubium, the lunar Sea of Clouds.

Shuttle Over Earth
17.04.2022

What's that approaching? Astronauts on board the International Space Station in 2010 first saw it far in the distance. Soon it enlarged to become a dark silhouette. As it came even closer, the silhouette appeared to be a spaceship.

APOD: 2023 February 27 Б Zodiacal Ray with Venus and Jupiter
27.02.2023

What's causing that unusual ray of light extending from the horizon? Dust orbiting the Sun. At certain times of the year, a band of sun-reflecting dust from the inner Solar System appears prominently after sunset or before sunrise and is called zodiacal light.

APOD: 2023 May 9 Б Shadows of Earth
9.05.2023

Can you find two Earth shadows in today's image? It's a bit tricky. To find the first shadow, observe that the top part of the atmosphere appears pink and the lower part appears blue. This is because the top half is exposed to direct sunlight, while the lower part is not.

Planet Earth at Twilight
27.12.2024

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.

Sudbury Indicates Nonstandard Particle Model
10.07.2001

The Sudbury Neutrino Observatory (SNO) has been detecting so few neutrinos from the Sun that the Standard Model of fundamental particles in the universe may have to be revised. Pictured above is the SNO as it was being built.

Europa s Freckles
1.11.2002

Europa, one of Jupiter's large Galilean moons, may well posses an ocean of liquid water hidden beneath its icy surface -- and so holds the tantalizing possibility of life. In this image, constructed with...

The Perseus Cluster of Galaxies
26.04.1997

Here is one of the largest objects that anyone will ever see on the sky. Each of the fuzzy blobs in the above picture is a galaxy, together making up the Perseus Cluster, one of the closest clusters of galaxies.

7,000 Stars and the Milky Way
17.05.1997

This panorama view of the sky is really a drawing. It was made in the 1940s under the supervision of astronomer Knut Lundmark at the Lund Observatory in Sweden. To create the picture, draftsmen...

Sunset Moonlight
21.11.2003

November's lunar eclipse was one of the shortest in recent years and also one of the brightest -- demonstrating that the Earth's shadow is not completely dark. The eclipsed Moon remained easily visible...