A Tornado on Planet Earth
22.07.2003

Large storms on Earth can spawn unusual, small, violent clouds known as tornadoes. Tornado clouds swirl as fast as hundreds of kilometers per second and, when they touch down, can destroy nearly everything in their long, narrow path. Many tornadoes last only a few minutes, but the largest and most dangerous can endure for hours.

Palomar at Night
7.08.2003

What's wrong with this picture? The summer night sky is clear, and moonlight illuminates the dome of the Hale 200-inch Telescope at Palomar Observatory, northeast of San Diego, California, USA. The familiar stars of the Teapot asterism in the constellation Sagittarius shine above the dome and to the right.

Jupiter's Ring Halo
7.08.1997

Why do small particles hover around Jupiter's rings? These particles form a previously unknown ring halo, recently discovered by the robot spacecraft Galileo currently orbiting Jupiter. Galileo obtained this image when on the far side of Jupiter - from this orientation scattered sunlight makes the halo ring visible.

The Sombrero Galaxy from HST
8.10.2003

Why does the Sombrero Galaxy look like a hat? Reasons include the Sombrero's unusually large and extended central bulge of stars, and dark prominent dust lanes that appear in a disk that we see nearly edge-on. Billions of old stars cause the diffuse glow of the extended central bulge.

A Manhattan Sunset
28.05.2004

Today, if it is clear, Manhattan will flood dramatically with sunlight just as the Sun sets precisely on the centerline of every street. Usually, the tall buildings that line the gridded streets of New York City's tallest borough will hide the setting Sun.

The Anthe Arc around Saturn
10.09.2008

What created this unusual partial ring around Saturn? Discovered last year, the arc was captured in clear detail only two months ago by the Saturn-orbiting Cassini spacecraft. Since the arc occupies the same orbit...

Space Shuttle Rising
15.04.2018

What's that rising from the clouds? The space shuttle. Sometimes, if you look out the window of an airplane at just the right time and place, you see something unusual -- in this case a space shuttle launching to orbit.

A Partial Solar Eclipse Sequence Reflected
27.12.2019

What's happened to the Sun? Yesterday, if you were in the right place at the right time, you could see the Sun rise partially eclipsed by the Moon. The unusual sight was captured...

Andromeda in Southern Skies
21.10.2022

Looking north from southern New Zealand, the Andromeda Galaxy never gets more than about five degrees above the horizon. As spring comes to the southern hemisphere, in late September Andromeda is highest in the sky around midnight though.

APOD: 2024 December 25 Б Diamond Dust Sky Eye
25.12.2024

Why is there a huge eye in the sky? Diamond dust. That is an informal term for small ice crystals that form in the air and flitter to the ground. Because these crystals...