The Medulla Nebula Supernova Remnant
18.01.2021

What powers this unusual nebula? CTB-1 is the expanding gas shell that was left when a massive star toward the constellation of Cassiopeia exploded about 10,000 years ago. The star likely detonated when it ran out of elements, near its core, that could create stabilizing pressure with nuclear fusion.

Cygnus Mosaic 2010 2020
11.02.2021

In brush strokes of interstellar dust and glowing gas, this beautiful skyscape is painted across the plane of our Milky Way Galaxy near the northern end of the Great Rift and the constellation Cygnus the Swan.

APOD: 2025 December 7 Б The Sun and Its Missing Colors
7.12.2025

It is still not known why the Sun's light is missing some colors. Here are all the visible colors of the Sun, produced by passing the Sun's light through a prism-like device.

The Whale and the Hockey Stick
21.08.2009

NGC 4631 is a big beautiful spiral galaxy seen edge-on (top right) only 25 million light-years away towards the small northern constellation Canes Venatici. This galaxy's slightly distorted wedge shape suggests to some a cosmic herring and to others the popular moniker of The Whale Galaxy.

The Red Spider Planetary Nebula
19.04.2017

Oh what a tangled web a planetary nebula can weave. The Red Spider Planetary Nebula shows the complex structure that can result when a normal star ejects its outer gases and becomes a white dwarf star.

Saturn at Night
2.11.2024

Saturn is bright in Earth's night skies. Telescopic views of the outer gas giant planet and its beautiful rings often make it a star at star parties. But this stunning view of Saturn's rings and night side just isn't possible from telescopes in the vicinity of planet Earth.

APOD: 2025 October 22 Б Comet Lemmon over the High Tatras
22.10.2025

Comet Lemmon putting on a show for cameras around the globe. Passing nearest to the Earth this week, the photogenic comet C/2025 A6 (Lemmon) is now extending two long tails : a blue ion tail and a white dust tail.

The Turbulent Neighborhood of Eta Carina
26.11.2003

How do violent stars affect their surroundings? To help find out, astronomers pointed the Hubble Space Telescope to the regions surrounding Eta Carina, a star showing signs that it may explode sometime in the next million years.

Young Suns of NGC 7129
3.10.2008

Young suns still lie within dusty NGC 7129, some 3,000 light-years away toward the royal constellation Cepheus. While these stars are at a relatively tender age, only about a million years old, it is likely that our own Sun formed in a similar stellar nursery some five billion years ago.

A Dusty Iris Nebula
10.06.2009

These clouds of interstellar dust and gas have blossomed 1,300 light-years away in the fertile star fields of the constellation Cepheus. Sometimes called the Iris Nebula and dutifully cataloged as NGC 7023, this is not the only nebula in the sky to evoke the imagery of flowers.