M27: Not A Comet
24.04.2004

While searching the skies above 18th century France for comets, astronomer Charles Messier diligently recorded this object as number 27 on his list of things which are definitely not comets. So what is it?

An Inner Neptune for 55 Cancri
1.09.2004

Is our Solar System unique? The discovery of a Neptune-mass planet in an sub-Mercury orbit around nearby Sun-like star 55 Cancri, announced yesterday along with the discovery of other similar systems, gives a new indication that planetary systems as complex as our own Solar System likely exist elsewhere.

The Horsehead Nebula
21.07.2009

One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.

Herschel s Cocoon
19.08.2011

In this remarkable infrared skyscape of interstellar clouds adrift in the high flying constellation Cygnus, the eye is drawn to the Cocoon Nebula. Also known as IC5146, the dusty star forming region is shown...

The Horsehead Nebula
21.10.2012

One of the most identifiable nebulae in the sky, the Horsehead Nebula in Orion, is part of a large, dark, molecular cloud. Also known as Barnard 33, the unusual shape was first discovered on a photographic plate in the late 1800s.

A Solar Filament Erupts
20.07.2014

What's happened to our Sun? Nothing very unusual -- it just threw a filament. Toward the middle of 2012, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME).

Infrared Orion from WISE
18.01.2015

The Great Nebula in Orion is an intriguing place. Visible to the unaided eye, it appears as a small fuzzy patch in the constellation of Orion. But this image, an illusory-color four-panel mosaic taken...

A Solar Filament Erupts
16.09.2018

What's happened to our Sun? Nothing very unusual -- it just threw a filament. Toward the middle of 2012, a long standing solar filament suddenly erupted into space producing an energetic Coronal Mass Ejection (CME).

A Mercury Transit Music Video from SDO
21.10.2019

What's that small black dot moving across the Sun? Mercury. Possibly the clearest view of Mercury crossing in front of the Sun in 2016 May was from Earth orbit. The Solar Dynamics Observatory obtained an uninterrupted vista recording it not only in optical light but also in bands of ultraviolet light.

APOD: 2025 March 16 Б Venus and the Triply Ultraviolet Sun
16.03.2025

This was a very unusual type of solar eclipse. Typically, it is the Earth's Moon that eclipses the Sun. In 2012, though, the planet Venus took a turn. Like a solar eclipse by the Moon, the phase of Venus became a continually thinner crescent as Venus became increasingly better aligned with the Sun.