X Class Flare
17.02.2011

On Valentine's Day (ET) the Sun unleased one of its most powerful explosions, an X-class flare. The blast was the largest so far in the new solar cycle. Erupting from active region AR1158...

Arecibo Telescope Collapse
9.12.2020

This was one great scientific instrument. Starting in 1963, the 305-meters across Arecibo Telescope in Puerto Rico USA reigned as the largest single-dish radio telescope in the world for over 50 years. Among numerous...

The Galactic Center Radio Arc
21.05.2002

What causes this unusual structure near the center of our Galaxy? The long parallel rays slanting across the top of the above radio image are known collectively as the Galactic Center Radio Arc and jut straight out from the Galactic plane.

Deimos: Small Martian Moon
3.10.1995

Mars has two tiny moons, Phobos and Deimos. Pictured above is Deimos, the smallest moon of Mars. In fact, Deimos is the smallest known moon in the Solar System measuring only 9 miles across.

Paranal Moonset
4.11.2006

Just before the rising Sun fully illuminated the 2,635 meter summit of Cerro Paranal in northern Chile, Gordon Gillet captured this stunning moonset. In the telephoto picture, a nearly full October Moon is silhouetting the impressive array of telescopes at ESO's Paranal Observatory.

Atacama s Cloudy Night
27.07.2013

Storm clouds do sometimes come to Chile's Atacama desert, known as the driest place on Earth. These washed through the night sky just last month during the winter season, captured in this panoramic view.

Flare Well AR2673
14.09.2017

Almost out of view from our fair planet, rotating around the Sun's western edge giant active region AR2673 lashed out with another intense solar flare followed by a large coronal mass ejection on September 10.

Star Factory Messier 17
8.09.2023

Sculpted by stellar winds and radiation, the star factory known as Messier 17 lies some 5,500 light-years away in the nebula-rich constellation Sagittarius. At that distance, this 1/3 degree wide field of view spans over 30 light-years.

Saturn at the Lunar Limb
22.02.2002

Gliding through the sky on Wednesday evening, February 20th, a first quarter Moon seemed to run over bright planet Saturn as viewed from much of North America. In this sharp sequence of telescopic digital...

Sunspots: Magnetic Depressions
22.03.1998

Our Sun has spots! These spots appear dark in photographs like the one above, but in fact sunspots are quite bright - they are just dark compared to the rest of the Sun. Sunspots are about the size of the Earth and frequently occur in groups, as shown above.