Stars and Mars
10.05.2008

Wandering through the evening sky, on May 4th planet Mars stood in line with Castor and Pollux, the two bright stars of the constellation Gemini. In this time exposure of the celestial alignment, Mars...

Large Sunspot Groups 10484 and 10486
27.10.2003

Two unusually large sunspot groups are now crossing the face of the Sun. Each group, roughly the size of Jupiter, is unusual not only for its size but because it is appearing over three years after solar maximum, the peak of solar surface activity.

Rosetta s Rendezvous
7.08.2014

On August 3rd, the Rosetta spacecraft's narrow angle camera captured this stunning image of the nucleus of Comet 67P/Churyumov-Gerasimenko. After 10 years and 6.5 billion kilometers of travel along gravity assist trajectories looping through interplanetary space, Rosetta had approached to within 285 kilometers of its target.

Comet 46P Wirtanen
15.11.2018

Periodic Comet 46P/Wirtanen is now the brightest comet in the night sky, but too faint to be seen by eye. From dark sky sites it could just become naked-eye visible though, as it's 5.4 year long looping orbit takes it closest to Earth and the Sun in mid December.

Milky Way over Pyramid of the Feathered Serpent
17.06.2019

To see the feathered serpent descend the Mayan pyramid requires exquisite timing. You must visit El Castillo -- in Mexico's YucatАn Peninsula -- near an equinox. Then, during the late afternoon if the sky is clear, the pyramid's own shadows create triangles that merge into the famous illusion of the slithering viper.

Solstice: Sunrises Around the Year
21.12.2020

Does the Sun always rise in the same direction? No. As the months change, the direction toward the rising Sun changes, too. The featured image shows the direction of sunrise every month during 2019 as seen from near the city of Amman, Jordan.

Zodiacal Light and Mars
11.03.2021

Just after sunset on March 7, a faint band of light still reaches above the western horizon in this serene, rural Illinois, night skyscape. Taken from an old farmstead, the luminous glow is zodiacal light, prominent in the west after sunset during planet Earth's northern hemisphere spring.

Companion of a Young Sun like Star
19.09.2008

Located just 500 light-years away toward the constellation Scorpius, this star is only slightly less massive and a little cooler than the Sun. But it is much younger, a few million years old compared to the middle-aged Sun's 5 billion years.

Halo from Atacama
18.05.2016

Influenced by the strong Pacific El Nino, cloudy skies have more often come to Chile's high Atacama Desert this season, despite its reputation as an astronomer's paradise. Located...

Crater On Ice
14.07.2000

Impact craters are common on Earth's moon but on Jupiter's large ice moon Europa, they are very rare. Over time, both bodies have been subjected to an intense pounding by the solar system's formative debris, but geological activity on Europa's surface seems to have erased most of these impact scars.