The Swirling Center of NGC 4261
5.12.1995

What evil lurks in the hearts of galaxies? The above picture by the Hubble Space Telescope of the center of the nearby galaxy NGC 4261 tells us one dramatic tale. Here gas and dust are seen swirling near this elliptical galaxy's center into what is almost certainly a massive black hole.

The Sloan Digital Sky Survey Telescope
17.06.1998

The Sloan Digital Sky Survey (SDSS) will soon begin. Pictured above is the 2.5-meter telescope poised to create the most ambitious sky map in the history of astronomy. SDSS will catalog one quarter of the sky down past 23rd magnitude ( R), obtaining redshifts for galaxies and quasars brighter than magnitude 19.

Breaking Distant Light
19.03.2002

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.

Dusting Spiral Galaxies
16.01.1998

How much dust is in spiral galaxies? Does it block out much of the starlight? Because astronomers rely on an accurate knowledge of galaxy properties to investigate a wide range of problems, like galaxy and quasar evolution and the nature of dark matter, answers to simple questions like this are key.

A Gallery of Gravitational Mirages
1.06.1999

The deeper you peer into the universe, the harder it is to see straight. The reason is that distant galaxies act as gravitational lenses, deflecting light that passes nearby. These deflections result in the distortion of background sources, and in some cases the creation of multiple images.

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.

ASCA X-Ray Observatory
20.02.1996

Today marks the third anniversary of the launch of the Advanced Satellite for Cosmology and Astrophysics (ASCA; renamed from Astro D when launched). ASCA, seen here superposed on galaxy M31, is a Japanese satellite for which NASA has provided some scientific equipment. ASCA carries four large-area X-ray telescopes.

The 100 Meter Green Bank Radio Telescope
11.03.2002

The largest single-dish fully steerable radio telescope began operation in 2000 August in Green Bank, West Virginia, USA. Dedicated as the Robert C. Byrd Green Bank Telescope, the device weighs over 30 times more than the Statue of Liberty, and yet can point anywhere in the sky more precisely than one thousandth of a degree.

Too Close to a Black Hole
7.12.2010

What would you see if you went right up to a black hole? Above is a computer generated image highlighting how strange things would look. The black hole has such strong gravity that light is noticeably bent towards it - causing some very unusual visual distortions.

The Very Large Array of Radio Telescopes
28.05.2002

The most photogenic array of radio telescopes in the world has also been one of the most productive. Each of the 27 radio telescopes in the Very Large Array (VLA) is the size of a house and can be moved on train tracks.