What are Solar Flares?

Most recent answer: 11/23/2009

Q:
What are solar flares and why do people think the end of the world will be because of the sun? Is it because something like this has happened before or are they just false predictions? Thanks
- Ashleigh (age 14)
Australia
A:
Solar flares are violent outbursts of energy from the sun.  They are due to an excess buildup of energy in the sun's corona-sphere caused by magnetic field fluctuations.  They emit energy in many forms, charged particles, x-rays, light, radio waves etc.  A particularly strong solar flare can disrupt radio communications on earth as well as endanger astronauts if they are not shielded.   See:   http://en.wikipedia.org/wiki/Solar_flare   for more information.

Yes, the end of the earth will be due to the sun.   As the sun grows older it runs out of fuel and tends to expand into what is called a red giant.  The sun's envelope will then engulf the inner planets including the earth.  Fortunately for us this will occur billions of years in the future so you don't have to be worried.   Astronomers have observed this feature of sun-like stars many times.   Take a look at  http://www.universetoday.com/guide-to-space/stars/red-giant-star/ .

LeeH

(published on 11/23/2009)