Anemic Spiral NGC 4921 from Hubble
15.05.2019

How far away is spiral galaxy NGC 4921? It's surpringly important to know. Although presently estimated to be about 300 million light years distant, a more precise determination could be coupled with its known recession speed to help humanity better calibrate the expansion rate of the entire visible universe.

APOD: 2025 November 25 Б Comet Lemmon and the Milky Way
25.11.2025

What did Comet Lemmon look like when it was at its best? One example is pictured here, featuring three celestial spectacles all at different distances. The closest spectacle is the snowcapped Meili Mountains, part of the Himalayas in China.

Milky Way and Aurora over Antarctica
27.07.2015

It has been one of the better skies of this long night. In parts of Antarctica, not only is it winter, but the Sun can spend weeks below the horizon. At China's Zhongshan Station, people sometimes venture out into the cold to photograph a spectacular night sky.

Swift Launches
22.11.2004

Where do gamma ray bursts occur? To help find out, NASA launched the Swift satellite on Saturday, as pictured above. What Swift is designed to do better than any previous satellite is to quickly locate these enigmatic explosions in both sky position and distance.

Three Arches Above Utah
24.05.2011

How many arches can you count in the above image? If you count both spans of the Double Arch in the Arches National Park in Utah, USA, then two. But since the above image...

Ring Scan
24.10.2007

Scroll right and cruise above the thin, icy rings of Saturn. This high resolution scan is a mosaic of images presented in natural color and recorded in May, over about 2.5 hours as the Cassini spacecraft passed above the unlit side of the rings.

APOD: 2023 July 2 Б Milky Way and Aurora over Antarctica
2.07.2023

It was one of the better skies of this long night. In parts of Antarctica, not only is it winter, but the Sun can spend weeks below the horizon. At China's Zhongshan Station, people sometimes venture out into the cold to photograph a spectacular night sky.

APOD: 2026 February 17 Б Tails of Comet Wierzchoе
17.02.2026

Some comets are regular guests of our solar neighborhood; others come by only once, never to return. We wonБt have another chance to see Comet C/2024 E1 (Wierzchoе), which is currently making its way through the inner Solar System. The hyperbolic orbit of this comet indicates that it will likely become an interstellar traveler.

M55: Globular Star Cluster
22.09.2000

The fifty-fifth entry in Charles Messier's catalog, M55 is a large and lovely globular cluster of around 100,000 stars. Only 20,000 light-years away in the constellation Sagittarius, M55 appears to earth-bound observers to be nearly 2/3 the size of the full moon.

The City Comet
26.03.1997

Undaunted by the artificial glow from one of the most famous urban skylines on Earth, comet Hale-Bopp shines above the city of New York, USA. Photographed on March 23rd, this view from New Jersey...