A Galaxy Gravitational Lens
20.12.1995

Sometimes it takes a keen eye to see a good mirage. Around the center of the red galaxy image in the above photograph lie four blue "smudges." Each smudge is actually a different image of the same background quasar. The central galaxy happens to fall directly in the light path of the quasar.

Methuselah Outcrop on Mars
2.05.2005

What the history of the outcropping of rock called Methuselah? The unusual rock group is visible on the left of the above image taken by the robot Spirit rover current exploring Mars. Methuselah was discovered while maneuvering over hilly terrain and shows unusual multiple layering that caught the attention of the rover science team.

Proxima Centauri: The Closest Star
4.12.2005

What is the closest star to our Sun? It is Proxima Centauri, the nearest member of the Alpha Centauri triple star system. Light takes only 4.22 years to reach us from Proxima Centauri. This...

Abell 2218: A Galaxy Cluster Lens
1.02.2000

Gravity can bend light. Almost all of the bright objects in this recently released Hubble Space Telescope image are galaxies in the cluster known as Abell 2218. The cluster is so massive and so compact that its gravity bends and focuses the light from galaxies that lie behind it.

An Orbiting Iceberg
21.08.1995

A comet nucleus, formed from the primordial stuff of the solar system, resembles a very dirty iceberg. Orbiting far from our Sun, it can remain frozen, preserved for billions of years. Occasionally, a chance gravitational encounter will alter this distant orbit and send the nucleus plummeting towards the inner solar system.

Observatory, Mountains, Universe
29.12.2014

The awesomeness in this image comes in layers. The closest layer, in the foreground, contains the Peak Terskol Observatory located in the northern Caucasus Mountains of Russia. The white dome over the 2-meter telescope is clearly visible. The observatory is located on a shoulder of Mt.

Moonset, Planet Earth
21.09.2002

During the Astro-1 astronomy mission of December, 1990, Space Shuttle astronauts photographed this stunning view of the setting full moon poised above the Earth's limb. In the foreground, towering clouds of condensing water vapor mark the extent of the troposphere, the lowest layer of the planet's life-sustaining atmosphere.

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.

Mars Over the Allalinhorn
8.03.2010

What's that bright object in the sky? A common question with answers that vary by time and season, the quick answer just after sunset in middle of last month, from the norther hemisphere, was Mars.

APOD: 2026 June 7 Б Jupiter and Venus from Earth
7.06.2026

It was visible around the world. The sunset conjunction of Jupiter (left) and Venus (right) in 2012 was visible almost no matter where you lived on Earth. Anyone on our planet with a clear western horizon at sunset could see them.