Seven Sisters Versus California
3.11.2009

On the upper right, dressed in blue, is the Pleiades. Also known as the Seven Sisters and M45, the Pleiades is one of the brightest and most easily visible open clusters on the sky. The Pleiades contains over 3,000 stars, is about 400 light years away, and only 13 light years across.

The Bubble Nebula
2.09.2010

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.

Young Suns of NGC 7129
4.09.2010

Young suns still lie within dusty NGC 7129, some 3,000 light-years away toward the royal constellation Cepheus. While these stars are at a relatively tender age, only a few million years old, it is likely that our own Sun formed in a similar stellar nursery some five billion years ago.

In the Shadow of Saturn
4.09.2011

In the shadow of Saturn, unexpected wonders appear. The robotic Cassini spacecraft now orbiting Saturn drifted in giant planet's shadow for about 12 hours in 2006 and looked back toward the eclipsed Sun. Cassini saw a view unlike any other.

Twisting with NGC 3718
3.08.2013

A careful look at this colorful cosmic snapshot reveals a surprising number of galaxies both near and far toward the constellation Ursa Major. The most striking is NGC 3718, the warped spiral galaxy near picture center. NGC 3718's spiral arms look twisted and extended, mottled with young blue star clusters.

The Umbra of Earth
26.01.2019

The dark, inner shadow of planet Earth is called the umbra. Shaped like a cone extending into space, it has a circular cross section most easily seen during a lunar eclipse. For example...

NGC 253: Dusty Island Universe
15.02.2024

Shiny NGC 253 is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Coin Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor.

APOD: 2025 August 28 Б Galaxies, Stars, and Dust
28.08.2025

This well-composed telescopic field of view covers over a Full Moon on the sky toward the high-flying constellation Pegasus. Of course the brighter stars show diffraction spikes, the commonly seen effect of internal supports in reflecting telescopes, and lie well within our own Milky Way galaxy.

The Dumbbell Nebula in Hydrogen and Oxygen
13.01.2003

The first hint of what will become of our Sun was discovered inadvertently in 1764. At that time, Charles Messier was compiling a list of "annoying" diffuse objects not to be confused with "interesting" comets.

A Tale of Two Nebulae
16.05.2003

This colorful telescopic view towards the northern constellation Lyra reveals dim outer regions around M57, popularly known as the Ring Nebula. While modern astronomers still refer to M57 as a planetary nebula, at one light-year across M57 is not a planet but the gaseous shroud of a dying sun-like star.