Iridescent by Moonlight
4.12.2021

In this snapshot from November 18, the Full Moon was not far from Earth's shadow. In skies over Sicily the brightest lunar phase was eclipsed by passing clouds though. The full moonlight was dimmed and momentarily diffracted by small but similar sized water droplets near the edges of the high thin clouds.

The Hydra Cluster of Galaxies
1.08.1996

You are flying through space and come to ... the Hydra Cluster of Galaxies. Listed as Abell 1060, the Hydra Cluster contains well over 100 bright galaxies. Clusters of galaxies are the largest gravitationally-bound objects in the universe.

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.

M24: A Sagittarius Starscape
21.09.2004

Many vast star fields in the plane of our Milky Way Galaxy are rich in clouds of dust, and gas. First and foremost, visible in the above picture are millions of stars, many of which are similar to our Sun.

APOD: 2002 September 18- A Sagittarius Starscape
18.09.2002

Many vast star fields in the plane of our Milky Way Galaxy are rich in clouds of stars, dust, and gas. First and foremost, visible in the above picture are millions of stars, many of which are similar to our Sun.

The Hydra Cluster of Galaxies
9.08.1997

You are flying through space and come to ... the Hydra Cluster of Galaxies. Listed as Abell 1060, the Hydra Cluster contains well over 100 bright galaxies. Clusters of galaxies are the largest gravitationally-bound objects in the universe.

The Colorful Clouds of Rho Ophiuchi
14.07.2006

This stunning mosiac of the sky around bright stars Antares (Alpha Scorpii) and Rho Ophiuchi reveals spectacular colors in a cosmic starscape. Near the top, Rho Ophiuchi and nearby stars are immersed in blue reflection nebulae - dust clouds that shine primarily by reflected starlight.

Milky Way Over Switzerland
21.02.2011

What's visible in the night sky during this time of year? To help illustrate the answer, a beautiful land, cloud, and skyscape was captured earlier this month over NeuchБtel, Switzerland. Visible in the foreground were the snow covered cliffs of the amphitheater shaped Creux du Van, as well as distant trees, and town-lit clouds.

Zooming in on the First Stars
10.06.2003

What became of the first stars? No known stars appear to be composed of truly primordial gas -- all of the stars around us have too many heavy elements. Our own Sun is thought to be a third generation star, with many second-generation stars seen in globular clusters.

A Giant Globular Cluster in M31
26.04.1996

G1, pictured above, is the brightest known globular cluster in the whole Local Group of galaxies. Also called Mayall II, it orbits the center of the largest nearby galaxy: M31. G1 contains over 300,000 stars and is almost as old as the entire universe.