Gamma Ray Moon
17.04.1999

What if you could see gamma rays (photons with more than 40 million times the energy of visible light)? If you could, the Moon would appear brighter than the Sun! This startling notion...

Signed, "A Black Hole"
16.05.1997

This artistic image is actually the signature of a supermassive black hole in the center of distant galaxy M84 - based on data recently recorded by Hubble's new Space Telescope Imaging Spectrograph (STIS). Very...

NGC 253: Dusty Island Universe
21.11.2009

Shiny NGC 253 Galaxy, is one of the brightest spiral galaxies visible, and also one of the dustiest. Some call it the Silver Dollar Galaxy for its appearance in small telescopes, or just the Sculptor Galaxy for its location within the boundaries of the southern constellation Sculptor.

Messier 101
27.11.2021

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way.

Messier 101
2.06.2023

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way.

Messier 101
16.05.2025

Big, beautiful spiral galaxy M101 is one of the last entries in Charles Messier's famous catalog, but definitely not one of the least. About 170,000 light-years across, this galaxy is enormous, almost twice the size of our own Milky Way.

APOD: 2023 September 10 Б An Annular Solar Eclipse over New Mexico
10.09.2023

What is this person doing? In 2012, an annular eclipse of the Sun was visible over a narrow path that crossed the northern Pacific Ocean and several western US states. In an annular solar...

Coronal Inflow
29.11.2001

The active Sun has thrown a lot our way lately, including storms of particles streaming outward in the solar wind and clouds of plasma which triggered awesome auroral displays. Still, a growing body...

The Vertical Magnetic Field of NGC 5775
27.01.2021

How far do magnetic fields extend up and out of spiral galaxies? For decades astronomers knew only that some spiral galaxies had magnetic fields. However, after NRAO's Very Large Array (VLA) radio telescope...

APOD: 2024 July 23 Б The Crab Nebula from Visible to X Ray
23.07.2024

What powers the Crab Nebula? A city-sized magnetized neutron star spinning around 30 times a second. Known as the Crab Pulsar, it is the bright spot in the center of the gaseous swirl at the nebula's core.