Comet Hale-Bopp and the Dumbbell Nebula
20.02.1997

Comet Hale-Bopp is now slowly moving across the morning sky. During its trip to our inner Solar System, the comet passes in front of several notable objects. Here Comet Hale-Bopp was photographed on February 11th superposed nearly in front of the picturesque Dumbbell Nebula, visible on the upper right.

The Heart and Soul Nebulas
14.09.2008

Is the heart and soul of our Galaxy located in Cassiopeia? Possibly not, but that is where two bright emission nebulas nicknamed Heart and Soul can be found. The Heart Nebula, officially dubbed IC 1805 and visible in the above zoomable view on the right, has a shape reminiscent of a classical heart symbol.

A Roll Cloud Over Uruguay
5.01.2010

What kind of cloud is this? A roll cloud. These rare long clouds may form near advancing cold fronts. In particular, a downdraft from an advancing storm front can cause moist warm air to rise, cool below its dew point, and so form a cloud.

Saturns Hyperion: A Moon with Odd Craters
27.02.2011

What lies at the bottom of Hyperion's strange craters? Nobody's sure. To help find out, the robot Cassini spacecraft now orbiting Saturn swooped past the sponge-textured moon in 2005 and 2010 and took images of unprecedented detail.

A Huge Solar Filament Erupts
15.12.2010

Click the arrow and watch an unusually long filament explode out from the Sun. The filament had been seen hovering over the Sun's surface for over a week before it erupted earlier this month.

GOES 16: Moon over Planet Earth
26.01.2017

Launched last November 19 from Cape Canaveral Air Force Station, the satellite now known as GOES-16 can now observe planet Earth from a geostationary orbit 22,300 miles above the equator. Its Advanced Baseline Imager captured this contrasting view of Earth and a gibbous Moon on January 15.

APOD: 2026 January 26 Б NGC 55: A Galaxy of Nebulas
26.01.2026

Can you see nebulas in other galaxies? Yes, some nebulas shine brightly enough -- if you know how to look. Clouds of hydrogen and oxygen emit light at very specific colors, and by isolating them, astronomers and astrophotographers can reveal structures that would otherwise be too faint to notice.

A Day in the Life of a Human Sundial
12.08.2017

Have you ever wanted to be a gnomon? Of course, a gnomon is the tall part of a sundial that casts a shadow. The gnomon's shadow moves as the Sun moves across the sky, indicating time by the shadow's position on the dial face.

Unusual Silica Rich Soil Discovered on Mars
18.12.2007

You're rolling across Mars when you unexpectedly uncover some unusually light soil. You stop. You turn. You return to inspect the soil and find out it is almost purely silica -- the main ingredient in quartz and glass. Such soil has never been found on Mars before. What created this soil?

APOD: 2025 January 6 Б Colliding Spiral Galaxies from Webb and Hubble
6.01.2025

Billions of years from now, only one of these two galaxies will remain. Until then, spiral galaxies NGC 2207 and IC 2163 will slowly pull each other apart, creating tides of matter, sheets of shocked gas, lanes of dark dust, bursts of star formation, and streams of cast-away stars.