Unusual Spires Found on Comet Wild 2
22.06.2004

How did unusual spires form on comet Wild 2? Close inspection of images taken of Comet Wild 2 by the passing Stardust spacecraft in January show numerous strange pinnacles as long as 100 meters long jutting off the surface. The pinnacles were unexpected - close-ups of other comets and asteroids show no such features.

The Backyard Universe
14.04.1999

How far can you see from your own backyard? Across the Solar System, even across our Galaxy, these sights are not difficult. Recently, however, amateur Paul Boltwood gazed across the universe. His record setting image is shown above in false color.

Wright Mons on Pluto
14.11.2015

Long shadows are cast by a low Sun across this rugged looking terrain. Captured by New Horizons, the scene is found just south of the southern tip Sputnik Planum, the informally named smooth, bright heart region of Pluto.

Dwarf Planet Ceres
4.02.2016

Dwarf planet Ceres is the largest object in the Solar System's main asteroid belt, with a diameter of about 950 kilometers (590 miles). Ceres is seen here in approximately true color, based on image data from the Dawn spacecraft recorded on May 4, 2015.

APOD: 2025 January 20 Б Comet ATLAS Rounds the Sun
20.01.2025

Why does Comet ATLAS have such colorful tails? Last week Comet C/2024 G3 (ATLAS) passed its closest to the Sun -- well inside the orbit of Mercury -- and brightened dramatically. Unfortunately, the comet was then so angularly near the Sun that it was very hard for humans to see. But NASA's SOHO spacecraft saw it.

SOFIA s Mirror
22.10.2004

The candy-dish appearance of this high-tech astronomical mirror is striking. Made of a special glass ceramic material called Zerodur, it actually measures 2.7 meters across. The transparent surface has not yet received a reflective...

Jupiter and the Moon s Shadowed Horizon
9.12.2004

Early Tuesday morning, December 7th, June Croft thought the southeastern sky above Atmore, Alabama, USA was beautiful. Watching the Moon rise through gossamer clouds, she noted, " ... the crescent Moon looked like it was held in the sky by a star just off its shadowed horizon." What was that star?

The Missing Craters of Asteroid Itokawa
21.11.2005

Where are the craters on asteroid Itokawa? No one knows. The Japanese robot probe Hayabusa recently approached the Earth-crossing asteroid and is returning pictures showing a surface unlike any other Solar System body yet photographed -- a surface possibly devoid of craters.

An Unusually Smooth Surface on Saturns Telesto
22.02.2006

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
17.02.2016

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.