APOD: 2026 June 21 Б Keogram: The Sky in 2025
20.06.2026

What if you could see the entire sky -- all at once -- for an entire year? That, very nearly, is what is pictured here. Every 15 seconds during 2025, an all-sky camera took an image of the sky over the Netherlands.

Gemini North Images Bow Shock Near Galactic Center
17.10.2000

What's going on near the center of our Galaxy? Glowing across the electromagnetic spectrum, the center of our Milky Way Galaxy is thought to be home to massive stars, rotating gas rings, and a massive black hole. Now the central Galactic zoo just got larger.

Coronal Rain, Solar Storm
14.11.2000

In this picture, the Sun's surface is quite dark. A frame from a movie recorded on November 9th by the orbiting TRACE telescope, it shows coronal loops lofted over a solar active region.

Islands in the Photosphere
14.03.2001

Awash in a sea of plasma and anchored in magnetic fields, sunspots are planet-sized, dark islands in the solar photosphere, the bright surface of the Sun. Before the enlightened(!) age of cameras, solar observers created detailed drawings of sunspots as they changed and progressed across the visible solar disk.

Pulsar Wind in the Vela Nebula
19.07.2001

The Vela pulsar was born 10,000 years ago at the center of a supernova -- an exploding star. In this Chandra Observatory x-ray image, the pulsar still produces a glowing nebula at the heart of the expanding cloud of stellar debris.

The Incredible Expanding Crab
26.12.2001

The Crab Nebula is cataloged as M1, the first on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, an expanding cloud of debris from the explosion of a massive star.

Shocked by Supernova 1987A
22.02.2002

Fifteen years ago today, the brightest supernova of modern times was sighted. Over time, astronomers have watched and waited for the expanding debris from this tremendous stellar explosion to crash into previously expelled material.

Henize 3 401: An Elongated Planetary Nebula
31.07.2002

How do dying stars eject their outer layers? Stars that create elegant planetary nebulas like Henize 3-401, pictured above, are not unusual, causing speculation that, one day, our own Sun may look like this.

The Spectrum of A Meteor
12.08.2004

Chasing the brief flash of a meteor trail across the sky with a very large telescope is a nearly impossible task. But on May 12, 2002, astronomers got lucky, as a bright meteor chanced across the narrow slit of their spectrograph at the Paranal Observatory.

Tycho and Copernicus: Lunar Ray Craters
4.03.2005

Dazzling in binoculars or a small telescope, the Moon is pocked with impact craters. During partial lunar phases, the craters along the terminator are cast in dramatic relief by strong shadows. But when the Moon is full some craters seem to sprout systems of bright radial lines or rays.