Sun Halo over Sweden
1.01.2018

What's happened to the Sun? Sometimes it looks like the Sun is being viewed through a giant lens. In the featured video, however, there are actually millions of tiny lenses: ice crystals. Water may freeze in the atmosphere into small, flat, six-sided, ice crystals.

Cygnus Shell Supernova Remnant W63
2.11.2018

The ghost of a long-dead star, the W63 supernova remnant shines like a faint cosmic smoke-ring along the plane of the Milky Way galaxy toward the northern constellation Cygnus the swan. Its wraithlike appearance is traced against the region's rich complex of interstellar clouds and dust by an eerie blue glow.

Doomed Star Eta Carinae
20.02.2019

Eta Carinae may be about to explode. But no one knows when - it may be next year, it may be one million years from now. Eta Carinae's mass - about 100 times greater than our Sun - makes it an excellent candidate for a full blown supernova.

APOD: 2025 January 28 Б Comet G3 ATLAS over Uruguay
28.01.2025

Comets can be huge. When far from the Sun, a comet's size usually refers to its hard nucleus of ice and rock, which typically spans a few kilometers -- smaller than even a small moon.

Orion on Film
7.02.2003

Orion, the Hunter, is one of the most easily recognizable constellations in planet Earth's night sky. But Orion's stars and nebulae don't look quite as colorful to the eye as they do in this lovely photograph, taken last month from Vekol Ranch south of Phoenix, Arizona, USA.

Our Galaxy in Stars, Gas, and Dust
27.09.1999

The disk of our Milky Way Galaxy is home to hot nebulae, cold dust, and billions of stars. The red nebulae visible in the above contrast-enhanced picture are primarily emission nebulae, glowing clouds of hydrogen gas heated by nearby, bright, young stars.

Southern Orion: From Belt to Witch
8.04.2008

Do you recognize the belt of Orion in this image? The familiar trio of stars, visible to the unaided eye, can be found across the upper left. Otherwise, the southern part of the constellation...

ISS and Astronaut
10.04.2009

These two frames, taken with a video camera and a telescope, reveal remarkable details of the International Space Station (ISS) orbiting some 350 kilometers above planet Earth. Recorded during last month's visit...

The Dance of Venus and Earth
3.06.2020

Every time Venus passes the Earth, it shows the same face. This remarkable fact has been known for only about 50 years, ever since radio telescopes have been able to peer beneath Venus' thick clouds and track its slowly rotating surface. This inferior conjunction -- when Venus and Earth are the closest -- occurs today.

The Sun in X rays from NuSTAR
23.11.2021

Why are the regions above sunspots so hot? Sunspots themselves are a bit cooler than the surrounding solar surface because the magnetic fields that create them reduce convective heating. It is therefore unusual that regions overhead -- even much higher up in the Sun's corona -- can be hundreds of times hotter.