Star Trails and the Bracewell Radio Sundial
13.07.2018

Sundials use the location of a shadow to measure the Earth's rotation and indicate the time of day. So it's fitting that this sundial, at the Very Large Array Radio Telescope Observatory in New Mexico, commemorates the history of radio astronomy and radio astronomy pioneer Ronald Bracewell.

Southern Cross over Chilean Volcano
25.01.2021

Have you ever seen the Southern Cross? This famous four-star icon is best seen from Earth's Southern Hemisphere. The featured image was taken last month in Chile and captures the Southern Cross just to the left of erupting Villarrica, one of the most active volcanos in our Solar System.

Optical Transient Near GRB970508 Shows Distant Redshift
13.05.1997

The GRB distance scale controversy may have just ended with a flash. Gamma Ray Bursts (GRBs) are powerful explosions occurring in seemingly random positions on the sky. They are so featureless and so poorly resolved, however, that their distances could not be determined.

Hideaway
20.06.2006

Is this a picture of a sunset from Earth's North Pole? Regardless of urban legends circulating the Internet, the answer is no. The above scene was drawn to be an imaginary celestial place that would be calm and peaceful, and therefore titled Hideaway.

APOD: 2025 June 29 Б Dark Sand Cascades on Mars
29.06.2025

Are these trees growing on Mars? No. Groups of dark brown streaks have been photographed by the Mars Reconnaissance Orbiter on melting pinkish sand dunes covered with light frost. The featured image was taken in 2008 April near the North Pole of Mars.