Red Moon, Green Beam
18.04.2014

This is not a scene from a sci-fi special effects movie. The green beam of light and red lunar disk are real enough, captured in the early morning hours of April 15. Of course, the reddened lunar disk is easy to explain as the image was taken during this week's total lunar eclipse.

GLAST Gamma Ray Sky Simulation
12.11.1998

This simulated image models the intensities of gamma rays with over 40 million times the energy of visible light, and represents how the sky might appear to the proposed Gamma-ray Large Area Space Telescope (GLAST) after its first year in orbit.

Simulation: A Disk Galaxy Forms
17.07.2012

How do galaxies like our Milky Way form? Since our universe moves too slowly to watch, faster-moving computer simulations are created to help find out. Green depicts (mostly) hydrogen gas in the above movie, while time is shown in billions of years since the Big Bang on the lower right.

Near the Nucleus of Hyakutake
28.03.1996

NASA's Hubble Space Telescope captured this image of the near-nuclear region of Comet Hyakutake on March 25 as the comet approached within 9.3 million miles of the Earth. It covers a relatively "small" 2,000 mile wide area with the sunward direction toward the lower right (tailward is upper left).

A Cosmic Snowball
30.05.1997

Like cosmic snowballs, fluffy comet-like objects the size of houses and composed mostly of water-ice, may be pummeling planet Earth 5 to 30 times a minute. This controversial theory was originally proposed in 1986 by Dr. Louis Frank (U. Iowa) based on data from NASA's Dynamics Explorer 1.

Illustris Simulation of the Universe
23.02.2020

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.

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.

Neutrinos in the Sun
5.06.1998

Neutrinos, along with things like electrons and quarks, are fundamental pieces of matter according to physicists' Standard Model. But neutrinos are hard to detect. Readily produced in nuclear reactions and particle collisions, they can easily pass completely through planet Earth without once interacting with any other particle.

The Broad Tail of PanSTARRS
30.03.2013

For northern hemisphere skygazers, fading Comet PanSTARRS (C/2011 L4) still hangs above the western horzion, after sunset but before moonrise in the coming days. Its perspective from planet Earth continues to reveal the comet's broad dust tail.

M81 and Arp s Loop
9.12.2010

One of the brightest galaxies in planet Earth's sky and similar in size to the Milky Way, big, beautiful spiral M81 lies 11.8 million light-years away in the northern constellation Ursa Major. This...