Hunter s Moon over the Alps
3.11.2012

A Full Moonset can be a dramatic celestial sight, and Full Moons can have many names. Late October's Full Moon, the second Full Moon after the northern hemisphere autumnal equinox, has been traditionally called the Hunter's Moon.

Country Sky versus City Sky
8.04.2020

Dark skies are disappearing from the world. With modernization comes artificial lighting that brightens the night. While these lights allow modern humans to see, much light is wasted up into the sky. This light...

APOD: 2023 December 13 Б Deep Field: The Heart Nebula
13.12.2023

What excites the Heart Nebula? First, the large emission nebula on the left, catalogued as IC 1805, looks somewhat like a human heart. The nebula glows brightly in red light emitted by its most prominent element, hydrogen, but this long-exposure image was also blended with light emitted by silicon (yellow) and oxygen (blue).

The Colorful Clouds of Rho Ophiuchi
9.07.2005

The many spectacular colors of the Rho Ophiuchi (oh'-fee-yu-kee) clouds highlight the many processes that occur there. The blue regions shine primarily by reflected light. Blue light from the star Rho Ophiuchi and nearby stars reflects more efficiently off this portion of the nebula than red light.

The Color of IC 1795
13.10.2011

This sharp cosmic portrait features glowing gas and obscuring dust clouds in IC 1795, a star forming region in the northern constellation Cassiopeia. Also cataloged as NGC 896, the nebula's remarkable details, shown...

The Solar Spectrum
23.04.2006

It is still not known why the Sun's light is missing some colors. Shown above are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

APOD: 2025 December 7 Б The Sun and Its Missing Colors
7.12.2025

It is still not known why the Sun's light is missing some colors. Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

The Witch Head Nebula
27.02.2001

Double, double toil and trouble; Fire burn, and cauldron bubble -- maybe Macbeth should have consulted the Witch Head Nebula. This suggestively shaped reflection nebula is associated with the bright star Rigel in the constellation Orion.

Close Up of the Lagoon Nebula
16.08.2004

Stars are battling gas and dust in the Lagoon Nebula but the photographers are winning. Also known as M8, this photogenic nebula is visible even without binoculars towards the constellation of Sagittarius. The energetic processes of star formation create not only the colors but the chaos.

M78 and Reflecting Dust Clouds in Orion
18.03.2008

An eerie blue glow and ominous columns of dark dust highlight M78 and other bright reflection nebula in the constellation of Orion. The dark filamentary dust not only absorbs light, but also reflects the light of several bright blue stars that formed recently in the nebula.