APOD: 2023 February 21 Б Comet ZTF over Yosemite Falls
21.02.2023

They are both falling. The water in Yosemite Falls, California, USA, is falling toward the Earth. Comet ZTF is falling toward the Sun. This double cosmic cascade was captured late last month as fading Comet C/2022 E3 (ZTF) had just passed its closest to planet Earth. The orange star just over the falls is Kochab.

APOD: 2024 April 22 Б Moon and Smoke Rings from Mt Etna
22.04.2024

Yes, but can your volcano do this? To the surprise of some, Mt. Etna emits, on occasion, smoke rings. Technically known as vortex rings, the walls of the volcano slightly slow the outside of emitted smoke puffs, causing the inside gas to move faster.

APOD: 2024 October 7 Б The Long Tails of Comet Tsuchinshan ATLAS
7.10.2024

A bright comet is moving into the evening skies. C/2023 A3 (TsuchinshanБATLAS) has brightened and even though it is now easily visible to the unaided eye, it is so near to the Sun that it is still difficult to see. Pictured, Comet TsuchinshanБATLAS was captured just before sunrise from an Andes Mountain in Peru.

APOD: 2024 October 8 Б Annular Eclipse over Patagonia
8.10.2024

Can you find the Sun? OK, but can you explain why thereБs a big dark spot in the center? The spot is the Moon, and the impressive alignment shown, where the Moon lines up inside the Sun, is called an annular solar eclipse.

APOD: 2025 September 4 Б NGC 4565: Galaxy on Edge
4.09.2025

Magnificent spiral galaxy NGC 4565 is viewed edge-on from planet Earth. Also known as the Needle Galaxy for its narrow profile, bright NGC 4565 is a stop on many telescopic tours of the northern sky, in the faint but well-groomed constellation Coma Berenices.

NGC 6992: A Glimpse of the Veil
28.09.2001

After 5,000 years, the gorgeous Veil Nebula is still turning heads. Cataloged as NGC 6992, these glowing filaments of interstellar shocked gas are part of a larger spherical supernova remnant known as the Cygnus Loop or the Veil Nebula -- expanding debris from a star which exploded over 5,000 years ago.

The Keyhole Nebula Near Eta Carinae
4.04.1996

The dark dusty Keyhole Nebula gets its name from its unusual shape. Designated NGC 3324, the Keyhole Nebula is a smaller region superposed on the bright Eta Carina Nebula. The Eta Carina Nebula...

The Hubble Deep Field
1.09.2002

Galaxies like colorful pieces of candy fill the Hubble Deep Field - one of humanity's most distant optical views of the Universe. The dimmest, some as faint as 30th magnitude (about four billion times...

The Hooker Telescope on Mt. Wilson
1.07.1995

In the 1920s, pictures from the Hooker Telescope on Mt. Wilson fundamentally changed our understanding of the cosmos. Astronomer Edwin Hubble, using photographs he took with this telescope, demonstrated that the objects his contemporaries called "spiral nebulae" were actually huge systems of stars - spiral galaxies, similar to our own Milky Way galaxy but incredibly distant.

Meteors Between Stars and Clouds
11.12.2002

Streaking high above diffuse clouds -- but well in front of distant stars -- are sand-sized bits of an ancient comet: meteors. These bits flaked off Comet Tempel-Tuttle during its pass through the inner Solar System about 150 years ago. Far in the background are stars toward the constellation of Ursa Major.