APOD: 2025 October 6 Б The Changing Ion Tail of Comet Lemmon
6.10.2025

How does a comet tail change? It depends on the comet. The ion tail of Comet C/2025 A6 (Lemmon) has been changing markedly, as detailed in the featured image sequenced over six days between September 25 and October 4 (left to right) from Texas, USA.

APOD: 2026 June 8 Б Comet R3 PanSTARRS Through Time
8.06.2026

What happens to a comet as it leaves our inner Solar System? Now, the arrival of a comet into the inner Solar System is typically heralded with great fanfare and high hopes that the comet will become bright and photogenic.

LINEAR s Tail and Two Nuclei
31.05.2001

Arcing toward southern skies in late March, this faint comet LINEAR - the one officially designated C/2001 A2 (LINEAR) - brightened unexpectedly. The outburst, apparently due to the fragmentation of its nucleus, delighted observers as the comet eventually increased to naked-eye brightness.

In the Arms of NGC 1097
16.11.2022

Spiral galaxy NGC 1097 shines in southern skies, about 45 million light-years away in the heated constellation Fornax. Its blue spiral arms are mottled with pinkish star forming regions in this colorful galaxy portrait.

Machholz Meets the Pleiades
11.01.2005

Sweeping northward in planet Earth's sky, comet Machholz extended its long ion tail with the Pleiades star cluster in the background on January 7th. This stunning view, recorded with a telephoto lens in skies over Oberjoch, Bavaria, Germany, emphasizes faint, complex tail structures and the scene's lovely blue and green colors.

Interstellar Interloper 2I Borisov
18.10.2019

After the 2017 detecton of 1I/'Oumuamua, comet 2I/Borisov has become the second recognized interstellar interloper. Like 'Oumuamua, Borisov's measured hyperbolic trajectory and speed as it falls toward the Sun confirm that its origin is from beyond our Solar System.

APOD: 2026 July 17 Б The Dust Trail of Comet Tempel 2
17.07.2026

Comet 10P/Tempel 2 orbits the Sun once every 5.4 years. Currently visible in binoculars or small telescopes toward the constellation Capricornus, the periodic comet is captured in this sharp telescopic image from July 11 sporting a bright nuclear region and pretty greenish coma.

3D 67P
28.11.2014

Get out your red/blue glasses and float next to a comet! The Rosetta mission lander Philae's ROLIS camera snapped the two frames used to create this stereo anaglyph for 3D viewing during...

Comet-like Clouds in the Cartwheel Galaxy
28.11.1996

In a cartwheel-shaped galaxy far, far away, huge comet-shaped clouds of gas have been discovered racing through the nucleus at about 700,000 miles per hour. The aptly named Cartwheel Galaxy is actually about 500 million light years distant, its suggestive shape created by a head-on collision with a smaller galaxy.

APOD: 2026 April 14 Б The Long Wispy Tail of Comet R3 (PanSTARRS)
14.04.2026

Why does Comet R3 (PanSTARRS) have a wispy tail? The newest bright member of the inner Solar System, Comet C/2025 R3 (PanSTARRS) is already extending an impressive stream of glowing gas. This tail starts from an unseen central nucleus of dirty ice that is likely a few kilometers across.