Sunday, March 8, 2009

What's Up? The Solar Cycle and the Danger of Solar Flares

As the end of winter approaches (hopefully!), the warmth of the sun will be well appreciated. To most people the sun looks like a simple, unchanging orb of light. But in reality, the sun is a wild, dangerous, and somewhat unpredictable broiling ball of hot gases. It is the gases blasted off the sun that cause the aurora borealis (northern lights).

The sun's surface is constantly bubbling and is frequently covered in small dark spots called sunspots. Sunspots appear when the sun's magnetic field is tangled up. If you ever get the opportunity to see the image of the sun projected from a telescope you could see a few of these "solar pimples."

The sun also, on occasion, emits highly energetic flares of material. Solar flares tend to occur around sunspots and are the sun's way of getting rid of built up magnetic energy.

The sun goes through cycles where it is really quiet for a while, has periods with a large amount of solar activity, and then quietens back down again. This cycle is referred to as the solar cycle and lasts roughly eleven years.

During 2009, the sun will be very inactive and will have only a few sunspots throughout the year. The number of spots will increase until 2012 when the solar cycle reaches its peak number of sunspots. Near the peak and for a while after the peak, solar flares occur very frequently. Occasionally one of these flares are aimed towards the Earth.

Just a few years ago a large flare was shot straight at Earth. On PEI the entire sky turned red when the energetic particles caused Earth's upper atmosphere to glow.

Solar flares may create beautiful auroras but can also cause serious damage.

In 1859 a massive solar flare hit Earth, causing charged particles to move in Earth's upper atmosphere, creating odd magnetic fields. That in turn caused electric currents to flow through long telegraph wires which sparked a few house fires.

A similar event occurred in 1989 which caused Quebec's power grid to go down for 9 hours, resulting in a loss of millions of dollars.

Since 1989, the power grids have had little upgrades and are overloaded. A solar flare like the one in 1989 would cause more widespread power outages.

Other than causing power outages, solar flares can cause large amounts of damage to satellites. Satellites carry satellite television service, cell phone and some internet signals, allow GPS to work, and monitor weather around the Earth. Since a majority of these satellites are unprotected they are vulnerable to being knocked out by a large flare. That kind of damage would cost millions or potentially billions if it were to be of a similar magnitude as the 1859 solar flare.

NASA currently has multiple observatories monitoring the sun, but the sun can change so quickly and flares travel so fast that they may hit Earth only a few hours after being detected. To keep an eye on what the sun is up to with the SOHO (SOlar and Heliospheric Observatory) spacecraft go to:

And while you're checking out what the sun is doing, let's check out what's up in the sky this month.

Starting off, the moon will be full on Mar. 11, and will still be very full looking (and eerie) for Friday the 13th. The full moon will diminish to a new moon by Mar. 26.

The Vernal Equinox, or first day of Spring, will occur on Mar. 20.

If you're an early riser, check out Venus around Mar. 25. For a few days around Mar. 25 you will be able to see Venus set in the evening sky and rise in the morning sky in the same night! This rare event only happens once every eight years. At dusk, Venus will be setting in the western sky and at dawn Venus will be rising in the eastern sky. It will appear as the brightest "star" in the sky. Check it out about 30 minutes after sunset and 30 minutes before sunrise. If you have binoculars or a telescope look for Venus' neat crescent shape.

NASA's Kepler mission launched Mar. 6 will be the first mission to look for Earth-like planets. It will look towards the constellation Cygnus, monitoring the brightness of a few hundred thousand stars, looking changes in the stars' brightness. If there is a periodic drop in a star's brightness, that means there is a planet crossing in front of the star, blocking some of its light. NASA scientists hope to discover a few Earth sized planets and help provide an estimate for how common Earth-like planets are in our galaxy.

Finally, on Sunday, Mar. 29 will be the monthly meeting of the Athena Community Astronomy Club at the Wilmot Community Centre in Summerside. Visitors are always very welcome to come.

Until next month, just look up!

Hey Kids...
Did you know that Venus glows in the dark? If the sun were turned off, a dim, deep red light could be seen coming from Venus. It glows like that because of chemical interactions happening in Venus' upper atmosphere. Check out Venus in the night sky for yourself by looking in the western sky (the sun sets in the western sky) at sunset. It won't be glowing red, but will be a brilliant bright yellow, brighter than any other star in the sky. If you have access to binoculars or a telescope, point them at Venus and you will see a crescent shape. See if you can notice the changes in Venus' phase night to night. Good luck in your celestial hunting!

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