Micro-Quasar GRS1915 Puffs
2.12.1997

On the far side of our Galaxy, gas clouds explode away from a small black hole. This might seem peculiar, as black holes are supposed to attract matter. But material falling toward a black hole collides and heats up, creating an environment similar to a quasar that is far from stable.

Hamlet of Oberon
31.01.1998

What's in a name? Since 1919, the International Astronomical Union has been charged with the task of establishing "conventional" nomenclature for planets, satellites, and surface features. For the remote Uranian system of moons, namesakes from Shakespearean works have been chosen.

Melas Chasma
29.07.2004

Steep cliffs drop into the rugged terrain of Melas Chasma in this stunning view from the Mars Express spacecraft orbiting the Red Planet. At a scale of 16 meters per pixel, the image data...

Identify this Phenomenon
13.09.2004

What caused this ring of colors? At the time of this writing, MIT Physics Professor Walter Lewin had yet to find someone who can give the correct explanation. Not students. Not colleagues. Not APOD editors. He wonders how the astute readers of APOD will do. Can you match wits with Professor Lewin?

Ceci n est pas un Meteore
19.08.2006

To paraphrase Magritte, "This is not a meteor". It's not a picture of a meteor either, but it was taken during last weekend's peak of the Perseid Meteor shower. Skywatching with friends...

Nova Over Iran
19.02.2007

A bright new nova is being studied by astronomers. The officially dubbed Nova Scorpii 2007 has become so bright in recent days that it is now visible to the unaided eye. Adventurous early morning sky enthusiasts should look in dark skies toward the constellation of the Scorpion, just below Jupiter and Antares.

One Armed Spiral Galaxy NGC 4725
6.06.2009

While most spiral galaxies, including our own Milky Way, have two or more spiral arms, NGC 4725 seems to have only one. In this sharp color image, the solo spira mirabilis is tightly wound, traced by bluish, newborn star clusters.

Iguacu Starry Night
14.05.2010

The arc of the southern Milky Way shone brightly on this starry night. Captured on May 4, in the foreground of this gorgeous skyview is the rainforest near the spectacular Iguaçu Falls and national park at the border of Brazil and Argentina.

Yuri s Planet
12.04.2012

On another April 12th, in 1961, Soviet cosmonaut Yuri Alexseyevich Gagarin became the first human to see planet Earth from space. Commenting on his view from orbit he reported, "The sky is very dark; the Earth is bluish. Everything is seen very clearly". To celebrate, consider this recent image from the orbiting International Space Station.

Jupiter and Venus from Earth
17.08.2014

It was visible around the world. The sunset conjunction of Jupiter and Venus in 2012 was visible almost no matter where you lived on Earth. Anyone on the planet with a clear western horizon at sunset could see them.