APOD: 2025 April 13 Б An Unusual Hole in Mars
13.04.2025

What created this unusual hole in Mars? Actually, there are numerous holes pictured in this Swiss cheese-like landscape, with all-but-one of them showing a dusty, dark, Martian terrain beneath evaporating, light, carbon dioxide ice.

The Deep Field
24.01.1996

The image above is part of the Hubble Deep Field and represents humanity's most distant yet optical view of the Universe. Galaxies like colorful pieces of candy fill the field, some as faint as 30th magnitude (about four billion times fainter than stars visible to the unaided eye).

NGC 1818: A Young Globular Cluster
7.03.1998

Globular clusters once ruled the Milky Way. Back in the old days, back when our Galaxy first formed, perhaps thousands of globular clusters roamed our Galaxy. Today, there are perhaps 200 left. Many globular clusters were destroyed over the eons by repeated fateful encounters with each other or the Galactic center.

Denizen of the Tarantula Nebula
7.04.1999

The star cluster at lower right, cataloged as Hodge 301, is a denizen of the Tarantula Nebula. An evocative nebula in the southern sky, the sprawling cosmic Tarantula is an energetic star forming region some 168,000 light-years distant in our neighboring galaxy the Large Magellanic Cloud.

Maneuvering in Space
22.05.2006

What arm is 17 meters long and sometimes uses humans for fingers? The Canadarm2 aboard the International Space Station (ISS). Canadarm2 has multiple joints and is capable of maneuvering payloads as massive as 116,000 kilograms, equivalent to a fully loaded bus. Canadarm2 is operated by remote control by a human inside the space station.

NGC 2261: Hubbles Variable Nebula
20.10.1999

What causes Hubble's Variable Nebula to vary? The unusual nebula pictured above changes its appearance noticeably in just a few weeks. Discovered over 200 years ago and subsequently cataloged as NGC 2661, the remarkable nebula is named for Edwin Hubble, who studied it earlier this century.

A Superior Conjunction Of Mercury
8.09.1999

In astronomical parlance, an interior planet is at superior conjunction when it is located on the opposite side of the Sun from Earth. Mercury, the solar system's innermost planet, zips past this point in its orbit today.

Comet McNaught from New STEREO Satellite
17.01.2007

The brightest comet of recent decades was a surprising first sight for a new camera in space. The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument onboard the Solar TErrestrial RElations Observatory (STEREO) satellite had just opened up on January 11 when it snapped the above image of Comet McNaught.

Crescent Saturn
23.10.2007

Saturn never shows a crescent phase -- from Earth. But when viewed from beyond, the majestic giant planet can show an unfamiliar diminutive sliver. This image of crescent Saturn in natural color was taken by the robotic Cassini spacecraft in May.

Saturn and Titan from Cassini
24.03.2008

Spectacular vistas of Saturn and its moon continue to be recorded by the Cassini spacecraft. Launched from Earth in 1997, robotic Cassini entered orbit around Saturn in 2004 and has revolutionized much of humanity's knowledge of Saturn, its expansive and complex rings, and it many old and battered moons.