Coronal Rain on the Sun
27.05.2018

Does it rain on the Sun? Yes, although what falls is not water but extremely hot plasma. An example occurred in mid-July 2012 after an eruption on the Sun that produced both a Coronal Mass Ejection and a moderate solar flare. What was more unusual, however, was what happened next.

Ice Halos by Moonlight
14.05.2022

An almost full moon on April 15 brought these luminous apparitions to a northern spring night over Alberta Canada. On that night, bright moonlight refracted and reflected by hexagonal ice crystals in high clouds created a complex of halos and arcs more commonly seen by sunlight in daytime skies.

APOD: 2024 January 16 Б The Orion You Can Almost See
16.01.2024

Do you recognize this constellation? Although it is one of the most recognizable star groupings on the sky, this is a more full Orion than you can see -- an Orion only revealed with long exposure digital camera imaging and post- processing.

September Sky
29.09.2000

Star clusters, planets, and a red giant posed for this portrait of the night sky from rural Jasper County, Iowa, USA. Astrophotographer Stan Richard recorded the four minute time exposure looking east around midnight on September 3rd at Ashton-Wildwood Park.

2dF Sees Waves of Galaxies
4.09.2001

How are galaxies distributed in the universe? This question is of more than aesthetic interest because the answer likely holds clues to composition of the universe itself. The above map shows the distribution...

Island Universe, Cosmic Sand
23.08.2002

On August 13, while counting Perseid meteors under dark, early morning Arizona skies, Rick Scott set out to photograph their fleeting but fiery trails. The equipment he used included a telephoto lens and fast color film. After 21 pictures he'd caught only two meteors, but luckily this was one of them.

NGC 2467: From Gas to Stars
31.01.2005

One might guess that the group of stars on the left is responsible for shaping the gas cloud on the right -- but it probably is not. Observations of many of the stars...

The Case of the Very Dusty Binary Star
25.09.2008

For astronomers, close binary star system BD+20 307 originally stood out because it is extremely dusty. A substantial amount of warm dust surrounding it causes the system to appear exceptionally bright at infrared wavelengths. Of course, dust associated with planet formation is often detected around young stars, stars only a few million years old.

Venus in the Moon
4.12.2008

On December 1, bright planets Venus and Jupiter gathered near the young crescent Moon, an inspiring celestial scene in early evening skies around the world. But from some locations the Moon actually passed in front of Venus, interrupting the tight grouping with a lunar occultation.

Betelgeuse Resolved
5.08.2009

The sharpest image ever of Betelgeuse shows a mammoth star that is slowly evaporating. Betelgeuse (sounds a lot like "beetle juice"), also known as Alpha Orionis, is one of the largest and brightest stars known. The star is a familiar orange fixture easily visible to the unaided eye toward the constellation of Orion.