Halloween and the Ghost Head Nebula
31.10.2004

Halloween's origin is ancient and astronomical. Since the fifth century BC, Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox (equal day / equal night) and a solstice (minimum day / maximum night in the northern hemisphere). With our modern calendar, however, the real cross-quarter day will occur next week.

Moon and Planets Over Catalonia
29.02.2012

Venus and Jupiter will appear unusually close in the sky over the next month. The planetary conjunction will be easily visible to the unaided eye because Venus will appear brighter than any background star, and Jupiter will be nearly as bright. To see the near-alignment, simply look to the west after sunset.

Meteors and Aurorae over Iceland
7.08.2013

What's going on behind that volcano? Quite a bit. First of all, the volcano itself, named Kirkjufell, is quite old and located in western Iceland near the town of GrundarfjЖrПur. In front...

NGC 1499: The California Nebula
10.03.2021

Could Queen Calafia's mythical island exist in space? Perhaps not, but by chance the outline of this molecular space cloud echoes the outline of the state of California, USA. Our Sun has its home within the Milky Way's Orion Arm, only about 1,000 light-years from the California Nebula.

Zodiacal Light and Mars
11.03.2021

Just after sunset on March 7, a faint band of light still reaches above the western horizon in this serene, rural Illinois, night skyscape. Taken from an old farmstead, the luminous glow is zodiacal light, prominent in the west after sunset during planet Earth's northern hemisphere spring.

Milky Way Auroral Flower
18.10.2022

Could the stem of our Milky Way bloom into an auroral flower? No, not really, even though it may appear that way in todayБs featured all-sky image. On the left, the central plane of our home galaxy extends from the horizon past the middle of the sky.

APOD: 2025 January 8 Б Supernova Remnants Big and Small
8.01.2025

What happens after a star explodes? A huge fireball of hot gas shoots out in all directions. When this gas slams into the existing interstellar medium, it heats up so much it glows. Two different supernova remnants (SNRs) are visible in the featured image, taken at the Oukaцmeden Observatory in Morocco.

The Circinus Galaxy
4.12.2000

Powerful forces are at play in the nearby Circinus Galaxy. Hot gas, colored pink, is being ejected out of the spiral galaxy from the central region. Much of Circinus' tumultuous gas, however, is concentrated in two rings.

Comet Kudo-Fujikawa: Days in the Sun
30.01.2003

Cruising through the inner Solar System, new Comet Kudo-Fujikawa reached perihelion, its closest approach to the Sun, yesterday, January 29. Passing within 28.4 million kilometers of the Sun, this comet came much closer than innermost planet Mercury basking only 57.9 million kilometers from our parent star.

Orange Sun Simmering
9.06.2010

Even a quiet Sun can be a busy place. And over the deep Solar Minimum of the past few years, our Sun has been unusually quiet. The above image, taken last week...