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.

Rigel and the Witch Head Nebula
31.10.2024

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

Blue Marble 2000
20.04.2000

This newly released digital portrait of our planet is reminiscent of the Apollo-era pictures of the "big blue marble" Earth from space. To create it, researchers at Goddard Space Flight Center's Laboratory...

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.

The Sun Spews X-rays
4.10.1995

Our Sun is really very hot. The Sun's outer atmosphere is so hot that it emits much light in the X-ray band, which was unexpected. X-rays are usually emitted from objects having a temperature in the millions of degrees, not the mere thousands of degrees of the Sun's surface.

Solstice Celebration
20.06.2004

Season's greetings! Today or tomorrow, depending on your time zone, the Sun reaches its northernmost point in planet Earth's sky marking a season change and the first solstice of the year 2004. In celebration, consider this delightfully detailed, brightly colored image of the active Sun.

Saturnian Aurora
23.01.1999

Girdling the second largest planet in the Solar System, Saturn's Rings are one of the most spectacular sights for earthbound telescopes. This image from the orbiting Hubble Space Telescope's STIS instrument, offers a striking view of another kind of ring around Saturn - pole encircling rings of ultraviolet aurora.

Red Saturn
10.02.2005

This strange, false-color image of otherwise familiar planet Saturn shows temperature changes based on thermal infrared emission in the gas giant's atmosphere and rings. Recorded from the Keck I telescope on Mauna Kea, the sharp, ground-based picture of Saturn's southern hemisphere is a mosaic of 35 images.

Unusual Aurora During Solar Wind Dropout
23.12.1999

On May 10, for some unknown reason, the Solar Wind virtually stopped. Normally our Sun emits a wind of between five and ten energetic particles per cubic centimeter moving outward at about 500 kilometers per second.