Io: Moon Over Jupiter
8.04.2012

How big is Jupiter's moon Io? The most volcanic body in the Solar System, Io (usually pronounced "EYE-oh") is 3,600 kilometers in diameter, about the size of planet Earth's single large natural satellite.

Geminid Meteors over Teide Volcano
17.12.2013

On some nights it rains meteors. Peaking two nights ago, asteroid dust streaked through the dark skies of Earth, showering down during the annual Geminids meteor shower. Astrophotographer Juan Carlos Casado captured the space weather event, as pictured above, in a series of exposures spanning about 2.3 hours using a wide angle lens.

Super Planet Crash
11.01.2015

Can you create a planetary system that lasts for 500 years? Super Planet Crash, the featured game, allows you to try. To create up to ten planets, just click anywhere near the central star.

Rigel and the Witch Head Nebula
15.01.2018

By starlight this eerie visage shines in the dark, a crooked profile evoking its popular name, the Witch Head Nebula. In fact, this entrancing telescopic portrait gives the impression that the witch has fixed her gaze on Orion's bright supergiant star Rigel.

The Space Station Crosses a Spotless Sun
28.10.2019

Typically, the International Space Station is visible only at night. Slowly drifting across the night sky as it orbits the Earth, the International Space Station (ISS) can be seen as a bright spot about once a month from many locations.

Novel Coronavirus Attacks Humanity
2.06.2020

Humanity is under attack. The attack is not from large tentacle-flailing aliens, but from invaders so small they can barely be seen, and so strange they are not even clearly alive. All over planet Earth, the human home world, DNA-based humans are being invaded by the RNA-based SARS-CoV2.

APOD: 2025 December 31 Б HH 222: The Waterfall Nebula
31.12.2025

What created the Waterfall Nebula? The origin is still being researched. The structure, officially designated Herbig-Haro 222, appears in the region of NGC 1999 in the Great Orion Molecular Cloud complex. The elongated gaseous stream stretches about ten light years but appears similar to a long waterfall on Earth.

Boosting Compton
6.06.1997

Even great observatories need a boost from time to time -- including the orbiting Compton Gamma-Ray Observatory. Sparkling reflections and the bright limb of the Earth are visible in this 1991 window view of Compton's release into orbit by the crew of the Space Shuttle Atlantis.

A Raging Storm System on Saturn
26.12.2011

It is one of the largest and longest lived storms ever recorded in our Solar System. First seen late last year, the above cloud formation in the northern hemisphere of Saturn started larger than the Earth and soon spread completely around the planet.

All the Water on Europa
24.05.2012

How much of Jupiter's moon Europa is made of water? A lot, actually. Based on the Galileo probe data acquired during its exploration of the Jovian system from 1995 to 2003, Europa posses a deep, global ocean of liquid water beneath a layer of surface ice.