Milky Way Molecule Map
30.04.1997

Where are the Milky Way's gas clouds and where are they going? Stars form in gas clouds, and the motion of gas clouds tell us about the size and rotation speed of our own Milky Way Galaxy.

TRACE and the Active Sun
15.05.1998

This dramatic high resolution picture looking across the edge of the Sun was taken April 24th by a telescope on board the newly launched Transition Region and Coronal Explorer (TRACE) satellite. It shows graceful arcs of intensely hot gas suspended in powerful looping magnetic fields which soar above a solar active region.

Spooky Star Forming Region DR 6
1.11.2004

How could stars form such a spooky and familiar shape as a human skull? First, the complex process of star formation creates nebulas of many shapes and sizes -- it is human perception that identifies the skull shape.

When Roses Aren t Red
24.03.2006

Not all roses are red of course, but they can still be very pretty. Likewise, the beautiful Rosette Nebula and other star forming regions are often shown in astronomical images with a predominately red hue - in part because the dominant emission in the nebula is from hydrogen atoms.

Halloween and the Ghost Head Nebula
31.10.2007

Halloween's origin is ancient and astronomical. Since the fifth century BC, Halloween has been celebrated as a cross-quarter day, a day halfway between an equinox (equal day / equal night) and a solstice (minimum day / maximum night in the northern hemisphere). With our modern calendar, however, the real cross-quarter day will occur next week.

M42: Inside the Orion Nebula
20.03.2013

The Great Nebula in Orion, an immense, nearby starbirth region, is probably the most famous of all astronomical nebulas. Here, glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away.

M2 9: Wings of a Butterfly Nebula
15.09.2013

Are stars better appreciated for their art after they die? Actually, stars usually create their most artistic displays as they die. In the case of low-mass stars like our Sun and M2-9 pictured above, the stars transform themselves from normal stars to white dwarfs by casting off their outer gaseous envelopes.

The Crab from Space
17.03.2018

The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, expanding debris from the death explosion of a massive star.

Active Galaxy NGC 1275
26.01.2023

Active galaxy NGC 1275 is the central, dominant member of the large and relatively nearby Perseus Cluster of Galaxies. Wild-looking at visible wavelengths, the active galaxy is also a prodigious source of x-rays and radio emission.

APOD: 2025 December 14 Б Juno Flyby of Ganymede and Jupiter
14.12.2025

What would it be like to fly over the largest moon in the Solar System? In 2021, the robotic Juno spacecraft flew past Jupiter's huge moon Ganymede and took images that have been digitally constructed into a detailed flyby.