Moonrise and Mountain Shadow
14.03.2020

What phase of the Moon is 3.14 radians from the Sun? The Full Moon, of course. Even though the Moon might look full for several days, the Moon is truly at its full phase when it is 3.14 radians (aka 180 degrees) from the Sun in ecliptic longitude.

APOD: 2023 March 15 Б Jupiter and Venus Converge over Germany
15.03.2023

This was a sky to show the kids. Early this month the two brightest planets in the night sky, Jupiter and Venus, appeared to converge. At their closest, the two planets were separated by only about the angular width of the full moon.

Star Party Trails
21.05.1999

Stargazing is fun! If you'd like to try it, this weekend may be your chance as many astronomy clubs and organizations will be hosting public celebrations of Astronomy Day on Saturday, May 22nd. In recent years, open house nights at observatories, astronomy club gatherings, and star parties have become increasingly popular.

Aristarchus Plateau
30.11.2007

Anchored in the vast lava flows of the Moon's Oceanus Procellarum lies the Aristarchus Plateau. The bright impact crater at the corner of the plateau is Aristarchus, a young crater 42 kilometers wide and 3 kilometers deep. Only slightly smaller, lava flooded Herodotus crater is above and to the left.

SOHO Composite: Coronal Mass Ejection
20.08.1998

This complex composite image of an ominous and spectacular event - an expanding storm of energetic particles from the Sun - was constructed using data recorded by the SOHO spacecraft on November 6, 1997. Four images...

GRB 990510: Another Unusual Gamma Ray Burst
26.05.1999

Another huge explosion has lit up the universe, and astronomers are studying it as best they can before the light fades away. Two weeks ago, the BATSE instrument on the orbiting NASA Great Observatory Compton detected unusually bright flashes of gamma-rays from a point deep in the southern sky.

Central Cygnus Skyscape
27.10.2009

In cosmic brush strokes of glowing hydrogen gas, this beautiful skyscape unfolds across the plane of our Milky Way Galaxy and the center of the northern constellation Cygnus the Swan. Recorded from a premier remote observatory site (ROSA) in southern France, the image spans about 6 degrees.

Infrared Orion from WISE
13.02.2013

The Great Nebula in Orion is a 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 composite of four...

The Soap Bubble Nebula
12.01.2015

Adrift in the rich star fields of the constellation Cygnus, this lovely, symmetric nebula was only recognized a few years ago and does not yet appear in some astronomical catalogs. In fact, amateur astronomer...

Ring of Fire over Easter Island
11.10.2024

The second solar eclipse of 2024 began in the Pacific. On October 2nd the Moon's shadow swept from west to east, with an annular eclipse visible along a narrow antumbral shadow path tracking...