A storm in a sunspot

Forest fires in California, Hurricane Isabel, extreme heat wave conditions in Europe, severe flooding in parts of India, scare of SARS in Ch...

Forest fires in California, Hurricane Isabel, extreme heat wave conditions in Europe, severe flooding in parts of India, scare of SARS in China 8212; it appears that the nature is at war with itself. Yet another chapter in this story of disasters concerns the latest attack of solar flares on earth.

On October 30 and 31, the entire globe witnessed the hurling of billions of tonnes of superhot gas in the direction of the earth. This surge of charged particles, called coronal mass ejections CME, affected orbiting satellites and disturbed ground-based communication and power systems in a few parts of the world. For instance, the Global Positioning System, was affected making its high precision service unavailable for some time. Japan lost contact with its Kodama satellite. In the earlier storm on October 25, it lost contact with the Midori 2 satellite. Aircraft flying far northern routes faced problems with high frequency voice-radio communications.

These solar flares are geomagnetic eruptions from the sun8217;s surface that send giant clouds of electrically charged particles racing towards earth on the solar winds. The source of all this current solar activity is giant sunspot 486. This week it unleashed two of the most powerful solar flares towards the earth. More explosions are possible in the days ahead.

A sunspot is a region on the sun that can be seen as a small dark spot through a telescope. They were discovered by Galileo in 1609 and are regions where powerful magnetic fields are concentrated. The sunspots reach the peak of their activity once in 11 years. Around this time, the strange behavior in the sun8217;s magnetic field is observed.

The current group of sunspots are the largest seen in a long while and have already produced several powerful explosions on the sun8217;s surface. During 1997-98, similar storms had shut down an AT038;T Telstar 401 satellite and Galaxy IV satellite. This had created problems in automated cash machines, airline ticketing systems and mobile phone connections.

People on the ground are not at risk from such solar storms. Airline travel is also safe. All this is possible because of earth8217;s thick atmosphere that deflects and absorbs incoming charged particles. In a way, magnetosphere protects us from solar flares radiation. However, astronauts in space are exposed to more radiation and space walks are not safe.

Solar physicists had given an early warning of these storms. This was based on the inputs received form the Sun-watching and Heliospheric Observatory SOHO spacecraft that is located midway between the earth and the sun. Ironically, few sensors of this spacecraft had to shut down because of the stormy weather. The performance of the SOHO spacecraft was hampered during the storm period and less-than-perfect data of the event has been received.

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Even though humans have escaped unscathed, these storms create problems for technology savvy countries, more so for their military hardware.

China8217;s manned space journey indicates that major world powers are planning to dominate space in the future. Well, ambitions of this kind will have to contend with solar storms. They indicate that space is no cake walk.