Andromeda over the Sahara Desert
10.07.2022

What is the oldest thing you can see? At 2.5 million light years distant, the answer for the unaided eye is the Andromeda galaxy, because its photons are 2.5 million years old when they reach you.

Callisto Full Face
19.01.2002

Callisto's surface shows its age. While probably formed at the same time as Io, the difference between the surfaces of these two moons of Jupiter could hardly be greater. Io's surface is young, shows practically no impact craters, and is continually being repaved by the lava exploding from its many large volcanoes

Quaoar: Large Asteroid in the Outer Solar System
9.10.2002

Asteroids almost as large as planets are still being discovered in our own Solar System. Recently an asteroid more than half the size of Pluto was found orbiting at a distance only a little further than the Solar System's most distant planet.

Europa's Surface
13.08.1996

Voyager spacecraft images of Europa's surface, like the one above, are suggestive of sea ice on Earth. The criss-crossing dark streaks may indeed be cracks in its ice-covered surface caused by Jupiter's tidal stresses accompanied by the freezing and expansion of an underlying layer of water.

The International Space Station Expands Yet Again
7.12.2002

The developing International Space Station (ISS) has changed its appearance yet again. Earlier this month the Space Shuttle Endeavor visited the ISS and installed the fourth of eleven pieces that will compose the Integrated Truss Structure. The new P-1 Truss is visible on the left, below the extended solar panels.

Just Passing Through
25.08.2007

M33 is a big, beautiful spiral galaxy a mere 3 million light-years away, understandably a popular target for enthusiastic astro-imagers. Just as understandably, interfering satellite trails and airplane streaks that are becoming more common in planet Earth's busy night sky are processed out of their finished images.

The International Space Station Expands Again
8.03.2011

The developing International Space Station (ISS) has changed its appearance again. In a recently completed rendezvous, the Space Shuttle orbiter Discovery, in its final flight, visited the ISS and added components that included the Leonardo Multi Purpose Logistics Module.

APOD: 2025 July 18 Б ISS Meets Saturn
17.07.2025

This month, bright planet Saturn rises in evening skies, its rings oriented nearly edge-on when viewed from planet Earth. And in the early morning hours on July 6, it posed very briefly with the International Space Station when viewed from a location in Federal Way, Washington, USA.

Saturn s Ancient Rings
16.12.2007

How old are Saturn's rings? No one is quite sure. One possibility is that the rings formed relatively recently in our Solar System's history, perhaps only about 100 million years ago when a moon-sized object broke up near Saturn.

Quadrantid Meteors and Aurora from the Air
6.01.2008

Where do meteor showers originate? To help answer this question, astronomers studied in some detail the Quadrantid meteor shower that occurred over this past weekend. In particular, astronomers with specialized cameras flew as part...