Snake in the Dark
20.06.2003

Dark nebulae snake across a gorgeous expanse of stars in this wide-field view toward the pronounceable constellation Ophiucus and the center of our Milky Way Galaxy. In fact, the central S-shape seen here is well known as the Snake Nebula.

Eclipsed Moon in the Milky Way
17.06.2011

On June 15, the totally eclipsed Moon was very dark, with the Moon itself positioned on the sky toward the center of our Milky Way Galaxy. This simple panorama captures totality from northern Iran in 8 consecutive exposures each 40 seconds long.

The Comet, the Owl, and the Galaxy
24.03.2017

Comet 41P/Tuttle-Giacobini-Kresak poses for a Messier moment in this telescopic snapshot from March 21. In fact it shares the 1 degree wide field-of-view with two well-known entries in the 18th century comet-hunting astronomer's famous catalog.

APOD: 2023 December 31 Б Illustris: A Simulation of the Universe
31.12.2023

How did we get here? Click play, sit back, and watch. A computer simulation of the evolution of the universe provides insight into how galaxies formed and perspectives into humanity's place in the universe.

SN Requiem: A Supernova Seen Three Times So Far
2.11.2021

We've seen this same supernova three times -- when will we see it a fourth? When a distant star explodes in a supernova, we're lucky if we see it even once.

M8: The Lagoon Nebula
17.08.2013

This beautiful cosmic cloud is a popular stop on telescopic tours of the constellation Sagittarius. Eighteenth century cosmic tourist Charles Messier cataloged the bright nebula as M8. Modern day astronomers recognize the Lagoon Nebula as an active stellar nursery about 5,000 light-years distant, in the direction of the center of our Milky Way Galaxy.

A Sky Full Of Hydrogen
18.12.1996

Interstellar space is filled with extremely tenuous clouds of gas which are mostly Hydrogen. The neutral hydrogen atom (HI in astronomer's shorthand) consists of 1 proton and 1 electron. The proton and electron spin like tops but can have only two orientations; spin axes parallel or anti-parallel.

APOD: 2026 June 18 Б Possible Supernova Remnant in Galactic Center
18.06.2026

Do you see that blue blob to the lower right of the image center? Astronomers think that it shows where a massive star exploded as a supernova whose light reached Earth 1,700 years ago.

Illustris Simulation of the Universe
12.05.2014

How did we get here? Click play, sit back, and watch. A new computer simulation of the evolution of the universe -- the largest and most sophisticated yet produced -- provides new insight into how galaxies formed and new perspectives into humanity's place in the universe.

Lyman Alpha Blob
2.07.2009

Dubbed a Lyman-alpha blob, an enormous cloud of hydrogen gas spans several hundred thousand light-years in this remarkable image (left), a composite of x-ray, optical, and infrared data from space and ground based observatories.