The Largest Rock in our Solar System
1.01.2023

There, that dot on the right, that's the largest rock known in our Solar System. It is larger than every known asteroid, moon, and comet nucleus. It is larger than any other local rocky planet.

Shocked by Supernova 1987A
23.02.2002

Fifteen years ago today, the brightest supernova of modern times was sighted. Over time, astronomers have watched and waited for the expanding debris from this tremendous stellar explosion to crash into previously expelled material.

Cosmic Construction Zone RCW 49
3.06.2004

Stars and planets appear to be under construction in dusty nebula RCW 49. This Spitzer Space Telescope false-color infrared view of the nearby stellar nursery shows that known, hot stars are well on their way to clearing out the nebula's central regions.

Fresh Tiger Strips on Saturns Enceladus
6.09.2005

The tiger stripes on Saturn's moon Enceladus might be active. Even today, they may be spewing ice from the moon's icy interior into space, creating a cloud of fine ice particles over the moon's South Pole and creating Saturn's mysterious E-ring.

M82: Galaxy with a Supergalactic Wind
25.04.2006

What's lighting up the Cigar Galaxy? M82, as this irregular galaxy is also known, was stirred up by a recent pass near large spiral galaxy M81. This doesn't fully explain the source of the red-glowing outwardly expanding gas, however.

The Host Galaxies of Long Duration GRBs
17.05.2006

What causes the powerful explosions knows as gamma-ray bursts? Astrophysicists still aren't sure, but the longest duration gamma-ray bursts (GRBs) seem to involve very massive stars. A new clue indicating this was uncovered recently by a series of images taken by the orbiting Hubble Space Telescope.

Giant Cluster Bends, Breaks Images
23.04.2000

What are those strange blue objects? Many are images of a single, unusual, beaded, blue, ring-like galaxy which just happens to line-up behind a giant cluster of galaxies. Cluster galaxies here appear yellow and -- together with the cluster's dark matter -- act as a gravitational lens.

A Big Black Hole Floats By
19.01.2000

A black hole glides silently through space. Is there any way to know it's there? Until last week, all objects that might be black holes in our Galaxy were part of binary star systems.

APOD: 2007 August 5- The Dotted Dunes of Mars
5.08.2007

What causes the black dots on dunes on Mars? As spring dawned on the Northern Hemisphere of Mars in 2004, dunes of sand near the poles begin to defrost. Thinner regions of ice typically thaw first revealing sand whose darkness soaks in sunlight and accelerates the thaw.

The Eagle Nebula in Hydrogen Oxygen, and Silicon
27.02.2008

Bright blue stars are still forming in the dark pillars of the Eagle Nebula. Made famous by a picture from the Hubble Space Telescope in 1995, the Eagle Nebula shows the dramatic process of star formation.