M13: The Great Globular Cluster in Hercules
18.05.2007

In 1714, Edmond Halley noted that M13 "shows itself to the naked eye when the sky is serene and the Moon absent." Of course, M13 is now modestly recognized as the Great Globular Cluster in Hercules, one of the brightest globular star clusters in the northern sky.

Mysterious Streaks Over Turkey
15.08.2007

What are they? Five streaks near the bottom of the above image taken near Ankara, Turkey on Sunday would be identified at first glance as meteors from the Perseids meteor shower peaking just that night. Unexpectedly, however, these streaks do not point back to the Perseids radiant in Perseus. Their origin is therefore somewhat unclear.

Shocked by Supernova 1987A
27.02.2012

Twenty five years ago, 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.

An Unusual Globule in IC 1396
14.04.2014

Is there a monster in IC 1396? Known to some as the Elephant's Trunk Nebula, parts of gas and dust clouds of this star formation region may appear to take on foreboding forms, some nearly human. The only real monster here, however, is a bright young star too far from Earth to hurt us.

Comet Catalina Tails
31.12.2015

A new year's treat for binoculars, as 2016 begins Comet Catalina (C/2013 US10) now sweeps through planet Earth's predawn skies near bright Arcturus, alpha star of Bootes. But this telescopic mosaic from December 21 follows the pretty tails of the comet across a field of view as wide as 10 full moons.

Southwest Mare Fecunditatis
2.03.2018

Frank Borman, James Lovell, and William Anders journeyed from Earth to the Moon and back again in December of 1968. From lunar orbit, their view of craters in southwest Mare Fecunditatis is featured in this stereo anaglyph, best experienced from armchairs on planet Earth with red/blue glasses.

APOD: 2024 February 14 Б Rosette Deep Field
13.02.2024

Can you find the Rosette Nebula? The large, red, and flowery-looking nebula on the upper left may seem the obvious choice, but that is actually just diffuse hydrogen emission surrounding the Cone and Fox Fur Nebulas.

APOD: 2026 June 14 Б 10 Days of Venus and Jupiter
13.06.2026

Venus and Jupiter may have caught your attention lately. The recent close conjunction of the two brightest planets in recent evening skies has been hard to miss. With Jupiter at the top, starting...

Callisto Full Face
8.12.1996

Callisto's surface shows its age. While probably formed at the same time as Io, the difference between the surfaces of these two moons of Jupiter could hardly be greater. Io's surface is young, shows practically no impact craters, and is continually being repaved by the lava exploding from its many large volcanoes.

Luna 9: First Soft Lander
25.08.1996

The Luna 9 spacecraft above performed the first soft landing on another planetary body. Following a series of failures, the Soviet probe touched down in the Moon's Oceanus Procellarum region February 3, 1966.