Jack C. Davis Observatory
- About the Observatory
- Astronomy Classes
- Astronomy Photos
- Buzz Aldrin Coin Raffle
- Contact and Staff
- NASA Image of the Day
- Observatory Weather Station
- Observatory Web Cam
- Planetary Walkway
- Recent News
Saturday Night Star Parties
Telescopes
Videos
See videos about Jack C. Davis Observatory:
Jack C. Davis Observatory
Planetary Walkway: Sun
| Previous: Introduction | Walkway Overview | Next: Mercury |
This photograph of the Sun, taken on December 19, 1973 during the third and final manned Skylab mission, shows one of the most spectacular solar flares ever recorded, spanning more than 588,000 kilometers (365,000 miles) across the solar surface. The flare gives the distinct impression of a twisted sheet of gas in the process of unwinding itself. In this photograph the solar poles are distinguished by a relative absence of supergranulation network, and a much darker tone than the central portions of the disk. Several active regions are seen on the eastern side of the disk. The photograph was taken in the light of ionized helium by the extreme ultraviolet spectroheliograph instrument of the U.S. Naval Research Laboratory. Image courtesy NASA Johnson Space Center (NASA-JSC).
Then God said: "Let there be lights in the dome of the sky, to separate day from night. Let them mark the fixed times, the days and the years, and serve as luminaries in the dome of the sky, to shed light upon the earth." And so it happened: God made the two great lights, the greater one to govern the day, and the lesser one to govern the night, and he made the stars....God saw how good it was. Genesis 1:14-19
The Sun is a star and the source of energy that sustains life in the Solar System. The next nearest star to Earth is Alpha Centauri 4.3 light-years (ly) away. A light-year is the distance light can travel in one year approximately 6 trillion miles. The Sun accounts for 99.8% of the entire mass of the Solar System. It rotates on its axis at the equator in 25 days and at the poles in approximately 36 days. Since the Sun is not solid and is made of a state of matter called plasma it undergoes differential rotation. The Sun is composed of 74% Hydrogen by mass and 25% Helium by mass. Its surface temperature is 5800 K and its core temperature is 15 million K (very hot). The Sun creates energy as a result of a hydrogen fusion in its core. For more information about our home star go to http://en.wikipedia.org/wiki/Sun.
| Sun Images | ||
|---|---|---|
 |
||
| Photograph of the Sun, taken on December 19, 1973 during the third and final manned Skylab mission. | ||