Astronomy Picture Of the Day (APOD)Filaprom on the Western Limb
A solar filament is an enormous stream of incandescent plasma suspended above the active surface of the Sun by looping magnetic fields. Seen against the solar disk it looks dark only because it's a little cooler, and so slightly dimmer, than the solar photosphere.
Supernova Remnant: The Veil Nebula
Ten thousand years ago, before the dawn of recorded human history, a new light would have suddenly have appeared in the night sky and faded after a few weeks. Today we know this light was from a supernova, or exploding star, and record the expanding debris cloud as the Veil Nebula, a supernova remnant.
Analemma over Taipei
Does the Sun return to the same spot on the sky every day? No. A better and more visual answer to that question is an analemma, a composite of images taken at the same time and from the same place over the course of a year.
Rock Fingers on Mars
There, just right of center, what is that? The surface of Mars keeps revealing new surprises with the recent discovery of finger-like rock spires. The small nearly-vertical rock outcrops were imaged last month by the robotic Curiosity rover on Mars.
Game: Super Planet Crash
Can you create a planetary system that lasts for 1000 years? Super Planet Crash, the featured game, allows you to try. To create up to ten planets, just click anywhere near the central star.
The Gamma Cygni Nebula
Supergiant star Gamma Cygni is at the center of the Northern Cross. Near the plane of our Milky Way galaxy, that famous asterism flies high in northern summer night skies in the constellation Cygnus the Swan.
Good Morning Planets from Chile
On June 15, innermost planet Mercury had wandered about as far from the Sun as it ever gets in planet Earth's sky. Near the eastern horizon just before sunrise it stands over distant Andes mountain peaks in this predawn snapshot from the valley of Rio Hurtado in Chile.
Strawberry Supermoon from China
There are four Full Supermoons in 2022. Using the definition of a supermoon as a Full Moon near perigee, that is within at least 90% of its closest approach to Earth in a given orbit, the year's Full Supermoon dates are May 16, June 14, July 13, and August 12.
In the Heart of the Virgo Cluster
The Virgo Cluster of Galaxies is the closest cluster of galaxies to our Milky Way Galaxy. The Virgo Cluster is so close that it spans more than 5 degrees on the sky - about 10 times the angle made by a full Moon.
Satellites Behind Pinnacles
What are all those streaks across the background? Satellite trails. First, the foreground features picturesque rock mounds known as Pinnacles. Found in the Nambung National Park in Western Australia, these human-sized spires are made by unknown processes from ancient sea shells (limestone). Perhaps more eye-catching, though, is the sky behind.