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.

Pluto in Enhanced Color
30.08.2015

Pluto is more colorful than we can see. Color data and images of our Solar System's most famous dwarf planet, taken by the robotic New Horizons spacecraft during its flyby in July, have been digitally combined to give an enhanced view of this ancient world sporting an unexpectedly young surface.

Pluto from above Cthulhu Regio
13.09.2015

New high resolution images of Pluto are starting to arrive from the outer Solar System. The robotic New Horizons spacecraft, which zoomed by Pluto in July, has finished sending back some needed engineering data and is now transmitting selections from its tremendous storehouse of images of Pluto and its moons.

The Space Station Crosses a Spotless Sun
27.10.2019

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
1.06.2020

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.

Iron in the Butterfly Nebula
20.07.2020

Can stars, like caterpillars, transform themselves into butterflies? No, but in the case of the Butterfly Nebula -- it sure looks like it. Though its wingspan covers over 3 light-years and its estimated surface temperature...

Circular Sun Halo
13.10.2023

Want to see a ring around the Sun? It's easy to do in daytime skies around the world. Created by randomly oriented ice crystals in thin high cirrus clouds, circular 22 degree halos are visible much more often than rainbows.

APOD: 2024 March 12 Б A Galaxy Shaped Rocket Exhaust Spiral
11.03.2024

What's that over the horizon? What may look like a strangely nearby galaxy is actually a normal rocket's exhaust plume -- but unusually backlit. Although the SpaceX Falcon 9 rocket was launched from...

APOD: 2025 September 10 Б The Great Lacerta Nebula
9.09.2025

It is one of the largest nebulas on the sky -- why isn't it better known? Roughly the same angular size as the Andromeda Galaxy, the Great Lacerta Nebula can be found toward the constellation of the Lizard (Lacerta).

A Leonid Meteor Over Sweden
20.11.2006

This past weekend, small remnant bits of a distant comet lit up the skies over much of planet Earth. Incoming reports, however, have this year's Leonid meteor shower as less active than Leonid meteor showers a few years ago.