Extraordinary Solar Halos
21.12.2018

Welcome to the December Solstice, the first day of winter in planet Earth's northern hemisphere and summer in the south. To celebrate, consider this extraordinary display of beautiful solar ice halos! More common than rainbows, simple ice halos can be easy to spot, especially if you can shade your eyes from direct sunlight.

APOD: 2023 May 7 Б The Helix Nebula from CFHT
7.05.2023

Will our Sun look like this one day? The Helix Nebula is one of brightest and closest examples of a planetary nebula, a gas cloud created at the end of the life of a Sun-like star.

Strange Rocks on Mars
29.07.1997

The rocks on Mars tell us stories about their past. To decipher these stories, a scientist must become a detective, searching for clues and fitting them with theories. The above photograph of the rocky Martian surface to the northeast of Pathfinder's landing site provides many such clues.

A Sun Halo Beyond Stockholm
10.01.2011

What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a large lens. In the above case, however, there are actually millions of lenses: ice crystals. As water freezes in the upper atmosphere, small, flat, six-sided, ice crystals might be formed.

A Flower Shaped Rock on Mars
9.03.2022

It is one of the more unusual rocks yet found on Mars. Smaller than a penny, the rock has several appendages that make it look, to some, like a flower. Although it would...

Colorful Airglow Bands Surround Milky Way
13.03.2022

Why would the sky glow like a giant repeating rainbow? Airglow. Now air glows all of the time, but it is usually hard to see. A disturbance however -- like an approaching storm -- may cause noticeable rippling in the Earth's atmosphere.

APOD: 2023 June 14 Б The Shark Nebula
14.06.2023

There is no sea on Earth large enough to contain the Shark nebula. This predator apparition poses us no danger as it is composed only of interstellar gas and dust. Dark dust like that featured here is somewhat like cigarette smoke and created in the cool atmospheres of giant stars.

A Sonic Boom
21.02.2001

Many people have heard a sonic boom, but few have seen one. When an airplane travels at a speed faster than sound, density waves of sound emitted by the plane cannot precede the plane, and so accumulate in a cone behind the plane.

Enceladus Ice Geysers
13.10.2007

Ice geysers erupt on Enceladus, bright and shiny inner moon of Saturn. Shown in this false-color image, a backlit view of the moon's southern limb, the majestic, icy plumes were discovered by instruments on the Cassini Spacecraft during close encounters with Enceladus in November of 2005.

Jupiter from the Stratosphere
3.06.2010

SOFIA, the Stratospheric Observatory for Infrared Astronomy, captured its "first light" images on May 26, from an altitude of 35,000 feet. While flying above most of planet Earth's infrared-absorbing water vapor, SOFIA's premier infrared views of the cosmos included this remarkable false-color image (right panel) of Jupiter.