APOD: 2024 July 29 Б Milky Way over Uluru
29.07.2024

What's happening above Uluru? A United Nations World Heritage Site, Uluru is an extraordinary 350-meter high mountain in central Australia that rises sharply from nearly flat surroundings. Composed of sandstone, Uluru has slowly formed over the past 300 million years as softer rock eroded away.

APOD: 2023 February 12 Б Mammatus Clouds over Nebraska
12.02.2023

When do cloud bottoms appear like bubbles? Normally, cloud bottoms are flat. This is because moist warm air that rises and cools will condense into water droplets at a specific temperature, which usually corresponds to a very specific height. As water droplets grow, an opaque cloud forms.

APOD: 2023 May 28 Б Ida and Dactyl: Asteroid and Moon
28.05.2023

This asteroid has a moon. The robot spacecraft Galileo on route to Jupiter in 1993 encountered and photographed two asteroids during its long interplanetary voyage. The second minor planet it photographed, 243 Ida, was unexpectedly discovered to have a moon.

APOD: 2025 July 23 Б Fireball over Cape San Blas
23.07.2025

Have you ever seen a fireball? In astronomy, a fireball is a very bright meteor -- one at least as bright as Venus and possibly brighter than even a full Moon. Fireballs are rare -- if you see one you are likely to remember it for your whole life.

APOD: 2024 March 27 Б The Coma Cluster of Galaxies
27.03.2024

Almost every object in the featured photograph is a galaxy. The Coma Cluster of Galaxies pictured here is one of the densest clusters known - it contains thousands of galaxies. Each of these galaxies houses billions of stars - just as our own Milky Way Galaxy does.

APOD: 2024 September 11 Б A Night Sky over the Tatra Mountains
11.09.2024

A natural border between Slovakia and Poland is the Tatra Mountains. A prominent destination for astrophotographers, the Tatras are the highest mountain range in the Carpathians. In the featured image taken...

APOD: 2025 September 23 Б NGC 6357: Cathedral to Massive Stars
23.09.2025

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it one of the most massive stars known.

APOD: 2023 April 10 Б IC 2944: The Running Chicken Nebula
10.04.2023

To some, it looks like a giant chicken running across the sky. To others, it looks like a gaseous nebula where star formation takes place. Cataloged as IC 2944, the Running Chicken Nebula spans about 100 light years and lies about 6,000 light years away toward the constellation of the Centaur (Centaurus).

APOD: 2025 November 17 Б Comet Lemmons Wandering Tail
17.11.2025

What has happened to Comet Lemmon's tail? The answer is blowing in the wind Б the wind from the Sun in this case. This continuous outflow of charged particles from...

APOD: 2009 April 6 The International Space Station Expands Again
6.04.2009

The developing International Space Station (ISS) has changed its appearance again. In a recently completed mission, the Space Shuttle orbiter Discovery visited the ISS and added components that included a new truss and new solar panels.