Messier 9 Close Up
23.03.2012

Renown 18th century astronomer Charles Messier described this 9th entry in his famous astronomical catalog as "Nebula, without star, in the right leg of Ophiuchus ...". But Messier 9 (M9) does have stars, known to modern astronomers as a globular cluster of over 300,000 stars within a diameter of about 90 light-years.

Umbra World
14.12.2012

On the morning of November 14, sky gazers from around the world gathered on this little planet to stand in the dark umbral shadow of the Moon. Of course, the Moon cast the shadow...

The Bubble Nebula
14.12.2013

Blown by the wind from a massive star, this interstellar apparition has a surprisingly familiar shape. Cataloged as NGC 7635, it is also known simply as The Bubble Nebula. Although it looks delicate, the 10 light-year diameter bubble offers evidence of violent processes at work.

A Cliff Looming on Comet 67P
20.05.2015

What that looming behind this gravel-strewn hill on Comet ChuryumovGerasimenko? A jagged cliff. The unusual double-lobed nucleus of Comet 67P/ChuryumovGerasimenko lends itself to unusual and dramatic vistas, another of which has been captured by the Rosetta spacecraft that arrived at the comet last September.

Aurora over Clouds
24.11.2015

Auroras usually occur high above the clouds. The auroral glow is created when fast-moving particles ejected from the Sun impact the Earth's magnetosphere, from which charged particles spiral along the Earth's magnetic field to strike atoms and molecules high in the Earth's atmosphere.

Red Cloudbow over Delaware
13.06.2018

What kind of rainbow is this? In this case, no rain was involved -- what is pictured is actually a red cloudbow. The unusual sky arc was spotted last month during sunset in Rehoboth Beach, Delaware, USA.

Ultima and Thule
3.01.2019

On January 1 New Horizons encountered the Kuiper Belt object nicknamed Ultima Thule. Some 6.5 billion kilometers from the Sun, Ultima Thule is the most distant world ever explored by a spacecraft from Earth.

APOD: 2023 June 12 Б The Largest Satellites of Earth
12.06.2023

WhatБs that near the Moon? ItБs the International Space Station (ISS). Although the ISS may appear to be physically near the Moon, it is not Б it is physically near the Earth.

APOD: 2025 April 15 Б Planetary Nebula NGC 1514 from Webb
15.04.2025

What happens when a star runs out of nuclear fuel? For stars like our Sun, the center condenses into a white dwarf while the outer atmosphere is expelled into space to appear as a planetary nebula.

NGC 1333: Stellar Nursery in Perseus
30.01.2026

NGC 1333 is seen in visible light as a reflection nebula, dominated by bluish hues characteristic of starlight reflected by interstellar dust. A mere 1,000 light-years distant toward the heroic constellation Perseus, it lies at the edge of a large, star-forming molecular cloud.