An Extremely Long Filament on the Sun
9.02.2015

Yesterday, the Sun exhibited one of the longest filaments ever recorded. It may still be there today. Visible as the dark streak just below the center in the featured image, the enormous filament extended across the face of the Sun a distance even longer than the Sun's radius -- over 700,000 kilometers.

Total Lunar Eclipse over Waterton Lake
28.09.2015

Recorded in 2014 April, this total lunar eclipse sequence looks south down icy Waterton Lake from the Waterton Lakes National Park in Alberta, Canada, planet Earth. The most distant horizon includes peaks in Glacier National Park, USA.

A Supernova through Galaxy Dust
23.02.2016

Telescopes around the world are tracking a bright supernova that occurred in a nearby dusty galaxy. The powerful stellar explosion was first noted earlier this month. The nearby galaxy is the photogenic Centaurus A, visible with binoculars and known for impressive filaments of light-absorbing dust that cross its center.

Just Another Day on Aerosol Earth
18.04.2020

It was just another day on aerosol Earth. For August 23, 2018, the identification and distribution of aerosols in the Earth's atmosphere is shown in this dramatic, planet-wide digital visualization. Produced in real...

APOD: 2024 February 25 Б A Phoenix Aurora over Iceland
25.02.2024

All of the other aurora watchers had gone home. By 3:30 am in Iceland, on a quiet September night, much of that night's auroras had died down. Suddenly, unexpectedly, a new burst of particles streamed down from space, lighting up the Earth's atmosphere once again.

APOD: 2024 August 13 Б Giant Jet from the International Space Station
13.08.2024

What's that on the horizon? When circling the Earth on the International Space Station early last month, astronaut Matthew Dominick saw an unusual type of lightning just beyond the Earth's edge: a gigantic jet. The powerful jet appears on the left of the featured image in red and blue.

APOD: 2025 July 13 Б Planetary Nebula Mz3: The Ant Nebula
13.07.2025

Why isn't this ant a big sphere? Planetary nebula Mz3 is being cast off by a star similar to our Sun that is, surely, round. Why then would the gas that is streaming away create an ant-shaped nebula that is distinctly not round?

M51: X Rays from the Whirlpool
11.07.2002

Fresh from yesterday's episode, a popular pair of interacting galaxies known as the Whirlpool debut here beyond the realm of visible light -- imaged at high energies by the orbiting Chandra X-ray Observatory. Still turning in a remarkable performance, over 80 glitering x-ray stars are present in the Chandra image data from the region.

Illusion and Evolution in Galaxy Cluster Abell 2667
5.03.2007

What's happening to the galaxies of cluster Abell 2667? On the upper left, a galaxy appears to be breaking up into small pieces, while on the far right, another galaxy appears to be stretched like taffy.

Aurora Shimmer, Meteor Flash
9.12.2018

Some night skies are serene and passive -- others shimmer and flash. The later, in the form of auroras and meteors, haunted skies over the island of Kvaløya, near Tromsø Norway on 2009 December 13. This 30 second long exposure records a shimmering auroral glow gently lighting the wintery coastal scene.