Astronomy Picture of the Day

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.

2004 October 22
See Explanation.  Clicking on the picture will download
 the highest resolution version available.

SOFIA's Mirror
Image Credit: Ron Strong (ARC / NASA)

Explanation: The candy-dish appearance of this high-tech astronomical mirror is striking. Made of a special glass ceramic material called Zerodur, it actually measures 2.7 metres across. The transparent surface has not yet received a reflective coating, so the weight-reducing internal honeycomb structure is visible with attractive blue and yellow tints provided by a protective tarp and background lighting. Recently unveiled, the telescope mirror is destined to fly on the Stratospheric Observatory For Infrared Astronomy (SOFIA). Since water vapour in Earth's troposphere tends to block infrared light, SOFIA will operate from a modified Boeing 747 jetliner at altitudes above 40,000 feet. As the largest airborne observatory in the world, SOFIA will explore a host of cosmic environments including sites of star birth and death, the formation of distant solar systems, and black holes in active galaxies.

Tomorrow's picture: another world series


< | Archive | Index | Search | Calendar | Glossary | Education | About APOD | >

Authors & editors: Robert Nemiroff (MTU) & Jerry Bonnell (USRA)
NASA Web Site Statements, Warnings, and Disclaimers
NASA Official: Jay Norris. Specific rights apply.
A service of: LHEA at NASA / GSFC
& Michigan Tech. U.