M51: Tidal Streams and H-alpha Ciffs
13.12.2024

An intriguing pair of interacting galaxies, M51 is the 51st entry in Charles Messier's famous catalog. Perhaps the original spiral nebula, the large galaxy with whirlpool-like spiral structure seen nearly face-on is also cataloged as NGC 5194. Its spiral arms and dust lanes sweep in front of its smaller companion galaxy, NGC 5195.

COMPTEL Explores The Radioactive Sky
24.07.1996

Diffuse gas clouds laced with radioactive aluminum atoms (Al26) line the plane of our Milky Way Galaxy! How do we see them? Relying on the Compton Effect, the COMPTEL instrument onboard NASA's immense orbiting Compton Gamma Ray Observatory can "see" the 1.8 million electron Volt gamma rays emitted by the radioactive decay.

Dark Matter Ring Modeled around Galaxy Cluster CL0024 17
16.05.2007

How do we know that dark matter isn't just normal matter exhibiting strange gravity? A new observation of gravitationally magnified faint galaxies far in the distance behind a massive cluster of galaxies is shedding new dark on the subject.

Gamma Ray Earth and Sky
6.12.2013

For an Earth-orbiting gamma-ray telescope, Earth is actually the brightest source of gamma-rays, the most energetic form of light. Gamma-rays from Earth are produced when high energy particles, cosmic rays from space, crash into the atmosphere.

Tycho and Clavius
5.08.2021

South is up in this detailed telescopic view across the Moon's rugged southern highlands. Captured on July 20, the lunar landscape features the Moon's young and old, the large craters Tycho and Clavius.

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.

LL Orionis: When Cosmic Winds Collide
22.05.2016

What created this great arc in space? This arcing, graceful structure is actually a bow shock about half a light-year across, created as the wind from young star LL Orionis collides with the Orion Nebula flow.

Optical Transient Near GRB970508 Shows Distant Redshift
13.05.1997

The GRB distance scale controversy may have just ended with a flash. Gamma Ray Bursts (GRBs) are powerful explosions occurring in seemingly random positions on the sky. They are so featureless and so poorly resolved, however, that their distances could not be determined.

The GRB 110328A Symphony
19.04.2011

A symphony of planet-wide observations began abruptly on March 28 when the Earth-orbiting Swift satellite detected a burst of high-frequency gamma-rays from GRB 110328A. When the same source flared again after a 45 minute pause it was clear this event was not a typical gamma-ray burst.