Message #160986

[Bianca]

Solar Mystery



Pasachoff wants to understand why the sun's corona—gas that extends millions of miles out from the sun—is millions of degrees hotter than the sun. The sun is just about 6,000 degrees Fahrenheit (3,300 degrees Celsius).

"Somehow energy has been put up into the corona from lower down, heating the gas, and we'd like to see how that happens," he said.

Scientists believe the coronal phenomenon has to do with the sun's magnetic field, and Pasachoff is looking to identify vibrating magnetic waves that move from the sun out into the corona.

(Related: "'Corkscrew' Waves Seen on Sun -- Keys to Solar Mystery?")

Scientists can't usually see the corona from Earth because its light is fainter than the blue sky created by our atmosphere.

Furthermore, instruments attached to space satellites can't isolate all areas of the corona because the sun and the light it scatters are too bright.

The only time certain observations are possible is when the moon blocks out the sun, creating a darker sky, which highlights the coronal light around the sun.

Although the sun is about 400 times bigger than the moon, it's also about 400 times more distant. So from the ground, the moon appears to be just a little bigger than the sun.