IC 4603: Reflection Nebula in Ophiuchius
23.07.2014

Why does this starfield photograph resemble an impressionistic painting? The effect is created not by digital trickery but by large amounts of interstellar dust. Dust, minute globs rich in carbon and similar in size to cigarette smoke, frequently starts in the outer atmospheres of large, cool, young stars.

The Supernova and Cepheids of Spiral Galaxy UGC 9391
6.06.2016

What can this galaxy tell us about the expansion rate of the universe? Perhaps a lot because UGC 9391, featured, not only contains Cepheid variable stars (red circles) but also a recent Type Ia supernova (blue X).

M15: Dense Globular Star Cluster
4.08.2000

Life might get dull at the core of M15 but the sky would always be bright with stars! In fact, only 40,000 light-years away in the constellation Pegasus, M15 is one of the most densely packed globular star clusters in our Milky Way Galaxy.

A Landing On Mars
4.07.1999

On July 4th, 1997 - using its own array of fireworks, a parachute, and airbags - the Mars Pathfinder spacecraft successfully came to rest on the surface of Mars at 10:07 AM Pacific Daylight Time. Ninety minutes before reaching the surface Pathfinder began a flurry of activity.

Flying Over the Columbia Hills of Mars
19.05.2008

What it would be like to fly over Mars? Combining terrain data from the orbiting Mars Global Surveyor spacecraft (now dormant) with information about the robotic Spirit rover currently rolling across Mars has resulted in a digital movie that shows what a flight over the Columbia Hills might look like.

The Matter of the Bullet Cluster
15.01.2017

What's the matter with the Bullet Cluster? This massive cluster of galaxies (1E 0657-558) creates gravitational lens distortions of background galaxies in a way that has been interpreted as strong evidence for the leading theory: that dark matter exists within.

Hubble s Messier 5
4.11.2017

"Beautiful Nebula discovered between the Balance [Libra] & the Serpent [Serpens] ..." begins the description of the 5th entry in 18th century astronomer Charles Messier's famous catalog of nebulae and star clusters. Though it appeared...

Sharpless 249 and the Jellyfish Nebula
7.03.2019

Normally faint and elusive, the Jellyfish Nebula is caught in this alluring telescopic field of view. The entire scene is a two panel mosaic constructed using narrowband image data, with emission from sulfur, hydrogen and oxygen atoms shown in red, green and blue hues.

Cosmic Clouds in the Unicorn
8.02.2020

Interstellar clouds of hydrogen gas and dust abound in this gorgeous skyscape. The 3 degree wide field of view stretches through the faint but fanciful constellation Monoceros, the Unicorn. A star forming region cataloged as NGC 2264 is centered, a complex jumble of cosmic gas, dust and stars about 2,700 light-years distant.

APOD: 2023 September 25 Б Arp 142: The Hummingbird Galaxy
25.09.2023

What's happening to this spiral galaxy? Just a few hundred million years ago, NGC 2936, the upper of the two large galaxies shown at the bottom, was likely a normal spiral galaxy -- spinning, creating stars -- and minding its own business.