A Gegenschein Lunar Eclipse
14.10.2015

Is there anything interesting to see in the direction opposite the Sun? One night last month, there were quite a few things. First, the red-glowing orb on the lower right of the featured image is the full moon, darkened and reddened because it has entered Earth's shadow.

The Perseus Cluster s X Ray Skull
31.10.2000

This haunting image from the orbiting Chandra Observatory reveals the Perseus Cluster of Galaxies in x-rays, photons with a thousand or more times the energy of visible light. Three hundred twenty million light-years distant, the Perseus Cluster contains thousands of galaxies, but none of them are seen here.

The Sun Rotating
12.03.2014

Does the Sun change as it rotates? Yes, and the changes can vary from subtle to dramatic. In the above time-lapse sequences, our Sun -- as imaged by NASA's Solar Dynamics Observatory -- is shown rotating though the entire month of January.

APOD: 2020 August 19 Б The Sun Rotating
19.08.2020

Does the Sun change as it rotates? Yes, and the changes can vary from subtle to dramatic. In the featured time-lapse sequences, our Sun -- as imaged by NASA's Solar Dynamics Observatory -- is shown rotating though an entire month in 2014.

The Multiwavelength Crab
11.05.2017

The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, expanding debris from massive star's death explosion, witnessed on planet Earth in 1054 AD.

The Multiwavelength Crab
4.03.2022

The Crab Nebula is cataloged as M1, the first object on Charles Messier's famous list of things which are not comets. In fact, the Crab is now known to be a supernova remnant, expanding debris from massive star's death explosion, witnessed on planet Earth in 1054 AD.

The Hydrogen Clouds of M33
3.10.2019

Gorgeous spiral galaxy M33 seems to have more than its fair share of glowing hydrogen gas. A prominent member of the local group of galaxies, M33 is also known as the Triangulum Galaxy and lies a mere 3 million light-years away.

Vela Pulsar: Neutron Star-Ring-Jet
9.06.2000

This stunning image from the orbiting Chandra X-ray Observatory is centered on the Vela pulsar -- the collapsed stellar core within the Vela supernova remnant some 800 light-years distant. The Vela pulsar is a neutron star. More massive than the Sun, it has the

Recycling Cassiopeia A
6.09.2019

Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew.

Recycling Cassiopeia A
23.01.2021

Massive stars in our Milky Way Galaxy live spectacular lives. Collapsing from vast cosmic clouds, their nuclear furnaces ignite and create heavy elements in their cores. After a few million years, the enriched material is blasted back into interstellar space where star formation can begin anew.