An Unusually Smooth Surface on Saturns Telesto
21.02.2006

Why is Saturn's small moon Telesto so smooth? Possibly Telesto is covered with a type of granular icy material similar to that suspected of covering Pandora, another of Saturn's small moon's. If so, Telesto might be more like a pile of rubble than a solid body.

Milky Way over the Pinnacles in Australia
16.02.2016

What strange world is this? Earth. In the foreground of the featured image are the Pinnacles, unusual rock spires in Nambung National Park in Western Australia. Made of ancient sea shells (limestone), how these human-sized picturesque spires formed remains unknown.

Full Moon in Mountain Shadow
20.10.2016

On October 15, standing near the summit of Hawaii's Mauna Kea and looking away from a gorgeous sunset produced this magnificent snapshot of a Full Moon rising within the volcanic mountain's shadow. An alignment across the Solar System is captured in the stunning scene and seeming contradiction of bright Moon in dark shadow.

Remembering NEOWISE
30.07.2021

It was just last July. If you could see the stars of the Big Dipper, you could find Comet NEOWISE in your evening sky. After sunset denizens of the north could look for the naked-eye comet below the bowl of that famous celestial kitchen utensil and above the northwestern horizon.

Jupiter over 2 Hours and 30 Minutes
18.01.2024

Jupiter, our Solar System's ruling gas giant, is also the fastest spinning planet, rotating once in less than 10 hours. The gas giant doesn't rotate like a solid body though.

APOD: 2024 September 16 Б Mercurys Vivaldi Crater from BepiColombo
15.09.2024

Why does this large crater on Mercury have two rings and a smooth floor? No one is sure. The unusual feature called Vivaldi Crater spans 215 kilometers and was imaged again in great detail by ESA's and JAXA's robotic BepiColombo spacecraft on a flyby earlier this month.

APOD: 2025 September 30 Б Comet Lemmon Brightens
29.09.2025

Comet Lemmon is brightening and moving into morning northern skies. Besides Comet SWAN25B and Comet ATLAS, Comet C/2025 A6 (Lemmon) is now the third comet currently visible with binoculars and on long camera exposures. Comet Lemmon was discovered early this year and is still headed into the inner Solar System.

Water Claimed in Evaporating Planet HD 209458b
17.04.2007

Planet HD 209458b is evaporating. It is so close to its parent star that its heated atmosphere is simply expanding away into space. Some astronomers studying this distant planetary system now believe they have detected water vapor among the gases being liberated.

North North Temperate Zone Little Red Spot
3.08.2017

On July 11, the Juno spacecraft once again swung near the turbulent Jovian cloud tops. On its seventh orbital closest approach this perijove passage brought Juno within 3,500 kilometers of the Solar System's largest planetary atmosphere.

Io Volcano Culann Patera
17.12.2002

What causes the unusual colors surrounding Io's volcanoes? Io, the innermost large moon of Jupiter, is known to be the most tumultuous body in the Solar System. Approximately the size of Earth...