Ios Surface: Under Construction
4.08.2013

Like the downtown area of your favorite city and any self-respecting web site ... Io's surface is constantly under construction. This moon of Jupiter holds the distinction of being the Solar System's most volcanically active body -- its bizarre looking surface continuously formed and reformed by lava flows.

HCG 87: A Small Group of Galaxies
8.08.2015

Sometimes galaxies form groups. For example, our own Milky Way Galaxy is part of the Local Group of Galaxies. Small, compact groups, like Hickson Compact Group 87 (HCG 87) shown above, are interesting partly because they slowly self-destruct.

Edge On Galaxy NGC 5866
8.03.2016

Why is this galaxy so thin? Many disk galaxies are actually just as thin as NGC 5866, pictured above, but are not seen edge-on from our vantage point. One galaxy that is situated edge-on is our own Milky Way Galaxy.

IC 5067 in the Pelican Nebula
25.05.2016

The prominent ridge of emission featured in this sharp, colorful skyscape is cataloged as IC 5067. Part of a larger emission nebula with a distinctive shape, popularly called The Pelican Nebula, the ridge spans about 10 light-years following the curve of the cosmic pelican's head and neck.

The Edge On Spindle Galaxy
24.07.2018

What kind of celestial object is this? A relatively normal galaxy -- but seen from its edge. Many disk galaxies are actually just as thin as NGC 5866, pictured here, but are not seen edge-on from our vantage point. A perhaps more familiar galaxy seen edge-on is our own Milky Way Galaxy.

NGC 6357: Cathedral to Massive Stars
29.08.2020

How massive can a normal star be? Estimates made from distance, brightness and standard solar models had given one star in the open cluster Pismis 24 over 200 times the mass of our Sun, making it one of the most massive stars known.

APOD: 2023 March 1 Б The Flaming Star Nebula
28.02.2023

Is star AE Aurigae on fire? No. Even though AE Aurigae is named the Flaming Star and the surrounding nebula IC 405 is named the Flaming Star Nebula, and even though the nebula appears to some like a swirling flame, there is no fire.

APOD: 2024 January 1 Б NGC 1232: A Grand Design Spiral Galaxy
31.12.2023

Galaxies are fascinating not only for what is visible, but for what is invisible. Grand spiral galaxy NGC 1232, captured in detail by one of the Very Large Telescopes, is a good example.

M27: Not a Comet
4.10.2024

While hunting for comets in the skies above 18th century France, astronomer Charles Messier diligently kept a list of the things encountered during his telescopic expeditions that were definitely not comets. This is number 27 on his now famous not-a-comet list.

APOD: 2025 February 3 Б Wolf Rayet Star 124: Stellar Wind Machine
2.02.2025

Some stars explode in slow motion. Rare, massive Wolf-Rayet stars are so tumultuous and hot that they are slowly disintegrating right before our telescopes. Glowing gas globs each typically over 30 times more massive than the Earth are being expelled by violent stellar winds.