![Request for Information – Potential [Placeholder for Prize]](https://assets.science.nasa.gov/dynamicimage/assets/science/psd/solar/2023/09/s/solarsystem_0.jpg?w=1024)
APOD
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.
XMM Launched
Explanation: X-ray astronomy entered a golden age earlier this month with the successful launch of the X-ray Multi-Mirror (XMM) satellite. XMM 's three huge telescope barrels each hold 58 concentric cylindrical mirrors, together totaling a surface area rivaling a tennis court . Each mirror has been gold plated to less than one-millimeter thickness to reflect normally penetrating X-rays . ESA's XMM joins NASA's Chandra X-ray Observatory as leading observatories in X-ray astronomy. The XMM satellite also carries a small optical and ultraviolet telescope. XMM 's unusually elliptical orbit around the Earth peaks nearly one-third of the way to the Moon. XMM's observing program during its planned two-year mission includes monitoring the hot surroundings of black holes , the fiery regions surrounding the centers of galaxies , the mysterious X-ray background light that appears to come from all directions, and the hot gas that glows between galaxies and stars.
| Date | December 21, 1999 |
|---|---|
| Credit | Drawing Credit: D. Ducros, XMM Team, ESA |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |