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.
X-Ray Earth
Explanation: Explanation : The Earth glows in many kinds of light, including the energetic X-ray band. Actually, the Earth itself does not glow - only aurora produced high in the Earth's atmosphere . Above is the first picture of the Earth in X-rays , taken in March with the orbiting Polar satellite . Bright X-ray emission is shown in red. Energetic ions from the Sun cause aurora and energize electrons in the Earth's magnetosphere . These electrons move along the Earth's magnetic field and eventually strike the Earth's ionosphere , causing the X-ray emission. These X-rays are not dangerous because they are absorbed by lower parts of the Earth's atmosphere.
| Date | December 30, 1996 |
|---|---|
| Credit | Credit: Polar, PIXIE, NASA |
| Authors & editors: | Robert Nemiroff (MTU) & Jerry Bonnell (UMCP) |
| A service of: |
ASD at NASA / GSFC, NASA Science Activation & Michigan Tech. U. |