Uranus' Moon Ariel: Valley World
3.03.1996

What formed Ariel's valleys? This question presented itself when Voyager 2 passed this satellite of Uranus in January 1986. Speculation includes that heating caused by the ancient tides of Uranus caused moonquakes and massive shifting of the moon's surface.

Yogi Rock
11.07.1997

This portrait of Yogi Rock, a now famous boulder on Mars, was recorded on Sol 3 by the Imager for Mars Pathfinder (IMP). Big and friendly looking like its Earth cartoon namesake Yogi Bear, Yogi Rock is a prominent visible feature at the Pathfinder landing site.

Globular Cluster M3
15.09.2003

This huge ball of stars predates our Sun. Long before humankind evolved, before dinosaurs roamed, and even before our Earth existed, ancient globs of stars condensed and orbited a young Milky Way Galaxy.

The Unusual Blueberries at Bylot Rock
17.08.2004

Why aren't these Martian rocks round? Small rocks dubbed blueberries have been found by the Opportunity rover all over Meridiani Planum on Mars, but the ones perched on Bylot rock have unusually non-spherical shapes. The strangely shaped blueberry rocks are shown above in an image taken by Opportunity's microscopic imager on August 9.

A Sun Halo Over Cambodia
8.02.2010

Have you ever seen a halo around the Sun? This fairly common sight occurs when high thin clouds containing millions of tiny ice crystals cover much of the sky. Each ice crystal acts like a miniature lens.

M7: Open Star Cluster in Scorpius
12.09.2012

M7 is one of the most prominent open clusters of stars on the sky. The cluster, dominated by bright blue stars, can be seen with the naked eye in a dark sky in the tail of the constellation of the Scorpion (Scorpius).

Martian Crater Shows Evidence of Dried Pond
3.06.1998

Did a pond once exist in this Martian crater? Recent photographs by the spacecraft Mars Global Surveyor, currently in orbit around Mars, show features unusual for Mars yet similar to a dried pond on Earth.

A Crescent Sunrise
17.08.1999

Normally, the Moon shows phases, but the Sun does not. The reason is founded in the fact that the Moon shines only by reflected sunlight. When the Moon is closer to the Sun than the Earth, only part of it appears to be lit - resulting in a familiar crescent-shaped phase.

Milky Way and Zodiacal Light over Australian Pinnacles
23.10.2022

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 a topic of research. The picturesque panorama was taken in 2017 September.

Looking Back Across Mars
25.05.2010

It's been a long trip for the Martian rover Opportunity. Last week Opportunity surpassed Viking 1 as the longest running mission on Mars, now extending well over six years. Pictured above, Opportunity's tire tracks cross a nearly featureless Martian desert, emanating from a distant horizon.