APOD: 2023 June 29 Б A Message from the Gravitational Universe
29.06.2023

Monitoring 68 pulsars with very large radio telescopes, the North American Nanohertz Observatory for Gravitational Waves (NANOGrav) has uncovered evidence for the gravitational wave (GW) background by carefully measuring slight shifts in the arrival times of pulses. These shifts are correlated between different pulsars in a way that indicates that they are caused by GWs.

APOD: 2023 December 31 Б Illustris: A Simulation of the Universe
31.12.2023

How did we get here? Click play, sit back, and watch. A computer simulation of the evolution of the universe provides insight into how galaxies formed and perspectives into humanity's place in the universe.

Breaking Distant Light
4.01.2009

In the distant universe, time appears to run slow. Since time-dilated light appears shifted toward the red end of the spectrum (redshifted), astronomers are able to use cosmological time-slowing to help measure vast distances in the universe.

Breaking Distant Light
20.09.2020

In the distant universe, time appears to run slowly. Since time-dilated light appears shifted toward the red end of the spectrum (redshifted), astronomers are able to use cosmological time-slowing to help measure vast distances in the universe.

Dark Matter in a Simulated Universe
25.10.2020

Is our universe haunted? It might look that way on this dark matter map. The gravity of unseen dark matter is the leading explanation for why galaxies rotate so fast, why galaxies orbit clusters...

The Average Color of the Universe
2.07.2002

What color is the universe? More precisely, if the entire sky was smeared out, what color would the final mix be? This whimsical question came up when trying to determine what stars are commonplace in nearby galaxies. The answer, depicted above, is a conditionally perceived shade of beige.

COBE Dipole: Speeding Through the Universe
5.02.1996

Our Earth is not at rest. The Earth moves around the Sun. The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group. The Local Group falls toward the Virgo Cluster of Galaxies.

Color the Universe
5.04.2020

Wouldn't it be fun to color in the universe? If you think so, please accept this famous astronomical illustration as a preliminary substitute. You, your friends, your parents or children, can print it out or even color it digitally.

Cosmic Latte: The Average Color of the Universe
27.12.2020

What color is the universe? More precisely, if the entire sky were smeared out, what color would the final mix be? This whimsical question came up when trying to determine what stars are commonplace in nearby galaxies. The answer, depicted above, is a conditionally perceived shade of beige. In computer parlance: #FFF8E7.

The Universe in Hot Gas
20.08.2002

Where is most of the normal matter in the Universe? Recent observations from the Chandra X-ray Observatory confirm that it is in hot gas filaments strewn throughout the universe. "Normal matter" refers to known elements and familiar fundamental particles.