The National Aeronautics and Space Administration announced that a solar flare arched its way up from the solar surface, helping to ring in 2013. Pictures of the flare were captured by the Solar Dynamics Observatory (SDO), an earth-orbiting spacecraft pointed at the Sun.
Numbers dealing with space are huge, but as flares go, this was a minor one. It was only the length of 20 Earth diameters. Earth has a diameter of 7,926.28 miles, or almost the flying distance between Sacramento, California and Melbourne, Australia--a 16 ½ hour flight in a commercial passenger jet aircraft flying 550 miles per hour. That same aircraft flying at that same speed would take two weeks of continuous flight to fly the length of the New Years solar flare—a phenomenon that lasted only four hours!
Tuesday’s flare was also an introduction to the current eleven year “high” for spectacular solar activity. Flares and sunspots are related phenomena, both caused by the turbulent solar atmosphere. Sunspots, relatively dark centers of magnetic activity often appear near or with magnetic flares like that photographed by the SDO on New Year’s Eve. Sunspots appear dark because they are relatively cooler than the surrounding solar surface, but are still hot enough at 8591°F (3800-4500° K) to completely boil iron.
Sunspots resemble Earth’s cyclones, but are caused by the magnetic fields generated by the rotation of the hot gases in the solar atmosphere. Since the Sun’s surface is not solid, the periods of rotation at different latitudes vary, and sometimes reverse, causing the magnetic imbalances. Flares erupt up and outward toward the solar corona and beyond. Flares are hotter than sunspots—with temperatures that reach dozens of millions of degrees. They often eject highly charged particles through the Sun’s outer atmosphere toward Earth. Most of the time, flares are invisible to observers on Earth. These flares can also heat the upper atmosphere, causing it to expand, which can cause satellites in low earth orbit like the Skylab space station to leave orbit prematurely.
Flares last from a few minutes to a few hours. Sunspots last for days or weeks.
Most of the time the magnetic “bottle” that surrounds Earth called “Earth’s Magnetic Field” protects us, but energy and charged particles from the largest flares (called x-class flares) can reach us and affect electronic communication (for instance television and cell phone reception). They are a greater hazard to spacecraft, manned and unmanned.
Spacecraft used by the various space agencies such as NASA, Roskosmos, and ESA on their planned Mars missions in mid-century must account for the hazard for the several years each of these missions may take.
Flares are more spectacular but less common than sunspots. Both increase in number during the same eleven year cycles. They form between 25 and 30 degrees north and south latitude at the beginning of the cycle and form within 5 to 10 degrees of the equator towards the end.
Sunspots usually travel in clusters somewhat like terrestrial thunderstorm cells, but much, much larger—small sunspots are only about 1500 miles wide—the distance between Sacramento and the outskirts of Lincoln, Nebraska, or between New York and Dodge City, Kansas. However, more than half a dozen or more earth-sized planets can fit into the larger ones. Imagine spending four whole days flying across a storm that could vaporize your airplane! Sunspots last longer than flares—a few days or weeks. If sunspots are vaguely like terrestrial cyclones, think of flares as lightning bolts on steroids.
There is some evidence to suggest that during times of decreased solar magnetic activity, the average temperature on Earth decreases. For instance, the period called “Little Ice Age” coincides with a sunspot minimum, or a reduced number of flares and sunspots between 1795 and 1820. Some scientists are claiming that despite the increased activity for 2013, and various evidences that the atmosphere is heating up, we are headed toward another “Little Ice Age” because 2013 is a relatively small maximum, and measurements predict a prolonged decrease of activity in the future.
In any case, the solar flare provided the most spectacular of the numerous fireworks displays ushering in 2013. What a spectacular beginning!
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