4000 Kilometers Above Saturns Iapetus
19.09.2007

What does the surface of Saturn's mysterious moon Iapetus look like? To help find out, the robotic Cassini spacecraft now orbiting Saturn was sent soaring last week just 2,000 kilometers from the unique equatorial ridge of the unusual walnut-shaped two-toned moon.

Europa and Jupiter from Voyager 1
5.09.2017

What are those spots on Jupiter? Largest and furthest, just right of center, is the Great Red Spot -- a huge storm system that has been raging on Jupiter possibly since Giovanni Cassini's likely notation of it 352 years ago. It is not yet known why this Great Spot is red.

HESS Gamma Ray Telescope
6.09.2002

Most ground-based telescopes with lenses and mirrors are hindered by the Earth's nurturing, protective atmosphere that blurs images and scatters and absorbs light. But this telescope was designed to detect extreme gamma rays - photons with over 100 billion times the energy of visible light - and actually requires the atmosphere to operate.

Gibbous Europa
15.12.2013

Although the phase of this moon might appear familiar, the moon itself might not. In fact, this gibbous phase shows part of Jupiter's moon Europa. The robot spacecraft Galileo captured this image mosaic during its mission orbiting Jupiter from 1995 - 2003.

Light from Cygnus A
23.01.2015

Celebrating astronomy in this International Year of Light, the detailed image reveals spectacular active galaxy Cygnus A in light across the electromagnetic spectrum. Incorporating X-ray data ( blue) from the orbiting Chandra Observatory, Cygnus A is seen to be a prodigious source of high energy x-rays.

Io s Surface: Under Construction
19.10.2002

Like the downtown area of your favorite city, the roads you drive to work on, and any self-respecting web site ... Io's surface is constantly under construction. This moon of Jupiter holds the distinction of being the Solar System's most volcanically active body -- its bizarre looking surface continuously formed and reformed by lava flows.

Ring Galaxy AM 0644 741 from Hubble
26.04.2004

How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars.

Ring Galaxy AM 0644 741 from Hubble
22.10.2005

How could a galaxy become shaped like a ring? The rim of the blue galaxy pictured on the right is an immense ring-like structure 150,000 light years in diameter composed of newly formed, extremely bright, massive stars.

APOD: 2025 April 2 Б Jupiter and Ring in Infrared from Webb
2.04.2025

Why does Jupiter have rings? Jupiter's main ring was discovered in 1979 by NASA's passing Voyager 1 spacecraft, but its origin was then a mystery. Data from NASA's Galileo spacecraft that...

APOD: 2026 February 11 Б A Year of Sunspots
11.02.2026

How many sunspots can you see? The central image shows the many sunspots that occurred in 2025, month by month around the circle, and all together in the grand central image. Each sunspot is magnetically cooled and so appears dark -- and can last from days to months.