Hydrogen Trifid
28.08.1998

Clouds of glowing hydrogen gas mingle with dark dust lanes in the Trifid Nebula, a star forming region in the constellation Sagittarius. In this and other similar emission nebulae, energetic ultraviolet light from an embedded hot young star strips electrons from the surrounding hydrogen atoms.

Autumn and the Active Sun
23.09.1998

As the Sun heads South, crossing the celestial equator today at 1:37 a.m. Eastern Time, Autumn begins for Earth's Northern Hemisphere. This Autumnal Equinox finds an increasingly active Sun steadily approaching a solar cycle maximum expected around the year 2003.

April s Moon and the Pleiades
14.04.2005

After parting with the Sun late last week, April's moon graced the early evening sky. Its slender, three-day-old crescent shares this lovely telescopic skyview with the nearby Pleiades star cluster. Here, the Moon...

NGC 2440: Cocoon of a New White Dwarf
3.07.1999

Like a butterfly, a white dwarf star begins its life by casting off a cocoon that enclosed its former self. In this analogy, however, the Sun would be a caterpillar and the ejected shell of gas would become the prettiest of all!

Sagittarius and the Central Milky Way
19.05.2009

What does the center of our Milky Way Galaxy look like? In visible light, no one knows! It is not possible to see the Galactic center in light our eyes are sensitive to because the thick dust in the plane of our Galaxy obscures it.

Rio Morning Moonset
20.04.2011

As the Sun rose, a nearly full Moon set in this serene seaside vista captured last Monday from Rio de Janeiro, Brazil. In the foreground, the reddened early morning sunlight illuminates a stretch of South Atlantic coastline.

Mars: Shadow at Point Lake
5.02.2013

What if you saw your shadow on Mars and it wasn't human? Then you might be the robotic Curiosity rover currently exploring Mars. Curiosity landed in Gale Crater last August and has been busy looking for signs of ancient running water and clues that Mars could once have harbored life.

Camelopardalids and ISS
25.05.2014

From a camp on the northern shores of the Great Lake Erie, three short bright meteor streaks were captured in this composited night skyscape. Recorded over the early morning hours of May 24, the meteors are illusive Camelopardalids.

APOD: 2026 February 10 Б In Green Company: Aurora over Norway
10.02.2026

Raise your arms if you see an aurora. With those instructions, two nights went by with, well, clouds -- mostly. On the third night of returning to same peaks, though, the sky not only cleared up but lit up with a spectacular auroral display.

Leonids from Orbit
29.11.2000

Here is what a meteor shower looks like from orbit. During the peak of the 1997 Leonid Meteor Shower, the MSX satellite imaged from above 29 meteors over a 48 minute period entering the Earth's atmosphere. From above, meteors create short bright streaks.