Mars in the Loop
8.11.2018

This composite of images spaced some 5 to 9 days apart, from late April (bottom right) through November 5 (top left), traces the retrograde motion of ruddy-colored Mars through planet Earth's night sky.

Exploring the Antennae
31.03.2022

Some 60 million light-years away in the southerly constellation Corvus, two large galaxies are colliding. Stars in the two galaxies, cataloged as NGC 4038 and NGC 4039, very rarely collide in the course of the ponderous cataclysm that lasts for hundreds of millions of years.

Dark Matter Map
14.08.2003

The total mass within giant galaxy cluster CL0025+1654, about 4.5 billion light-years away, produces a cosmic gravitational lens -- bending light as predicted by Einstein's theory of gravity and forming detectable images of even more distant background galaxies.

Long Lovejoy and Little Dumbbell
26.02.2015

Buffeted by the solar wind, Comet Lovejoy's crooked ion tail stretches over 3 degrees across this telescopic field of view, recorded on February 20. The starry background includes awesome bluish star Phi Persei below, and pretty planetary nebula M76 just above Lovejoy's long tail.

APOD: 2023 January 25 Б LDN 1622: The Boogeyman Nebula
25.01.2023

To some, the dark shape looks like a mythical boogeyman. Scientifically, Lynds' Dark Nebula (LDN) 1622 appears against a faint background of glowing hydrogen gas only visible in long telescopic exposures of the region.

The Great Globular Cluster in Hercules
26.09.2024

In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shows itself to the naked Eye, when the Sky is serene and the Moon absent." Of course...

APOD: 2025 June 1 Б UGC 1810: Wildly Interacting Galaxy from Hubble
1.06.2025

What's happening to this spiral galaxy? Although details remain uncertain, it surely has to do with an ongoing battle with its smaller galactic neighbor. The featured galaxy is labelled UGC 1810 by itself, but together with its collisional partner is known as Arp 273.

Blue Lagoon
25.08.2006

Stars come and go as you slide your cursor over this engaging image of M8, aka the Lagoon Nebula. Of course, the nebula is itself a star-forming region, but the stars that appear and disappear here include background and foreground stars that by chance lie along the same line of sight.

M13: The Great Globular Cluster in Hercules
20.05.2021

In 1716, English astronomer Edmond Halley noted, "This is but a little Patch, but it shews itself to the naked Eye, when the Sky is serene and the Moon absent." Of course...

Rosetta's Comet in View
10.09.2021

Faint comet Churyumov-Gerasimenko (67P) sweeps past background stars in the constellation Taurus and even fainter distant galaxies in this telescopic frame from September 7. About 5 years ago, this comet's 4 kilometer spanning...