APOD: 2024 October 21 Б Comet Tsuchinshan ATLAS over California
21.10.2024

The tails of Comet Tsuchinshan-ATLAS were a sight to behold. Pictured, C/2023 A3 (TsuchinshanБATLAS) was captured near peak impressiveness last week over the Eastern Sierra Mountains in California, USA. The comet not only showed a bright tail, but a distinct anti-tail pointing in nearly the opposite direction.

VDB 142 in Cepheus
11.10.2001

A gorgeous collection of dust and gas nebulae in the Northern Milky Way graces the high and far off constellation of Cepheus. With colors based on astronomical filters, this close up of the region highlights stars embedded in curiously shaped cosmic clouds.

Sigma Octantis and Friends
28.06.2018

South pole star Sigma Octantis (of the constellation Octans) is on the left of this starry expanse spanning over 40 degrees across far southern skies. You'll have to look hard to find it, though.

Comet Encke Returns
23.12.2003

It's back. Every 3.3 years, Comet Encke swoops back into our inner Solar System. First officially discovered in 1786, Comet Encke is on its 59 th documented return, making it one of the best-studied comets on the sky.

Comet SWAN Brightens
4.10.2006

A newly discovered comet has brightened enough to be visible this week with binoculars. The picturesque comet is already becoming a favored target for northern sky imagers. Pictured above just last week, Comet SWAN showed a bright blue-green coma and an impressive tail.

APOD: 2024 October 6 Б The Magnificent Tail of Comet McNaught
6.10.2024

Comet McNaught, the Great Comet of 2007, grew a spectacularly long and filamentary tail. The magnificent tail spread across the sky and was visible for several days to Southern Hemisphere observers just after sunset. The amazing ion tail showed its greatest extent on long-duration, wide-angle camera exposures.

The Reddening of M71
9.12.2014

Now known to be a globular star cluster at the tender age of 10 billion years, M71 is a mere 13,000 light-years away within the narrow boundaries of the faint constellation Sagitta. Close...

Comet NEAT Passes an Erupting Sun
24.02.2003

As Comet NEAT flared last week, the Sun roared. Just as the comet swooped inside the orbit of Mercury and developed a long and flowing tail of gas and dust, the Sun emitted a huge Coronal Mass Ejection (CME).

The Cepheids of M100
10.01.1996

Can this blinking star tell us how fast the universe is expanding? Many astronomers also believe it may also tell us the age of the universe! The photographed "Cepheid variable" star in M100 brightens and dims over the course of days as its atmosphere expands and contracts.

Asteroid 3753: Earth's Curious Companion
18.06.1997

Earth is not alone. It orbits the Sun with a small companion: Asteroid 3753. First discovered in 1986 and designated 1986 OT, this five kilometer rock was recently found to orbit the Sun while executing a strange dance with the Earth. A portion of the asteroid's complex orbit is shown above.