Comet Holmes Grows a Tail
5.11.2007

Comet Holmes continues to be an impressive sight to the unaided eye. The comet has diminished in brightness only slightly, and now clearly appears to have a larger angular extent than stars and planets. Astrophotographers have also noted a distinctly green appearance to the comet's coma over the past week.

Whirlpool with Comets
8.12.2016

Not a comet, bright spiral galaxy Messier 51 is popularly known as the Whirlpool Galaxy. Just off the handle of the Big Dipper in northern skies, you can spot it at the upper left in this image from December 1st. The pretty 4 by 2.5 degree wide field of view does contain two comets though.

Comet Garradd and the Coat Hanger
9.09.2011

Sweeping through planet Earth's night sky, last weekend Comet Garradd (C/2009 P1) visited this lovely star field along the Milky Way in the constellation Vulpecula. Suggestively oriented, the colorful skyscape features stars in the asterism known as the Coat Hanger with the comet's tail pointing toward the southeast.

Comet Holmes in Outburst
26.10.2007

Comet 17P/Holmes stunned comet watchers across planet Earth earlier this week. On October 24, it increased in brightness over half a million times in a matter of hours. The outburst transformed it from...

Outbound Comet ZTF
24.03.2023

Former darling of the northern sky Comet C/2022E3 (ZTF) has faded. During its closest approach to our fair planet in early February Comet ZTF was a mere 2.3 light-minutes distant. Then known as the green comet, this visitor from the remote Oort Cloud is now nearly 13.3 light-minutes away.

Philae Attempts Comet Nucleus Landing
11.11.2014

Today humanity will make its first attempt to land a probe on the nucleus of a comet. As the day progresses, the Philae (fee-LAY) lander will separate from the Rosetta spacecraft and head down...

Ganymede: Torn Comet Crater Chain
15.12.2001

This striking line of 13 closely spaced craters on Jupiter's moon Ganymede was photographed by the Galileo spacecraft in 1997. The picture covers an area about 120 miles wide and the chain of craters cuts across a sharp boundary between dark and light terrain. What caused this crater chain?

Comet Catalina Tails
1.01.2016

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.

APOD: 2023 August 21 Б Introducing Comet Nishimura
21.08.2023

Will Comet Nishimura become visible to the unaided eye? Given the unpredictability of comets, no one can say for sure, but it currently seems like a good bet. The comet was discovered only ten days ago by Hideo Nishimura during 30-second exposures with a standard digital camera.

Comet Linear (WM1) Brightens
6.12.2001

A comet bright enough to be seen with binoculars is swooping into southern skies. Comet C/2000 WM1 (LINEAR) continues to brighten and develop tails as it nears its closest approach of the Sun in late January 2002.