Discover the cosmos! Each day a different image or photograph of our fascinating universe is featured, along with a brief explanation written by a professional astronomer.
June 20, 1999
Explanation: Pictured above is one of the world's premiere radio astronomical observatories: The Very Large Array (VLA). Each antenna dish is as big as a house (25 metres across) and mounted on railroad tracks. The VLA consists of 27 dishes - together capable of spanning the size of a city (35 kilometres). The VLA is the most sensitive radio telescope ever, and, through interferometry, can resolve a golf ball-sized radio source 150 kilometres away (0.04 arcsec). The VLA is continually making new discoveries, including determining the composition of galaxies, passing comets, quasars, HII regions, and clusters of galaxies. The VLA is also used to receive the weak radio signals broadcast from interplanetary spacecraft. The VLA is located in New Mexico, USA. A significant upgrade of VLA's capabilities is planned.
Authors & editors:
Jerry Bonnell (USRA)
NASA Technical Rep.: Jay Norris. Specific rights apply.
A service of: LHEA at NASA/ GSFC
& Michigan Tech. U.