And the beleaguered ozone layer, infamous for growing that gaping hole each year, is about to get a slight breather thanks to less abuse from solar activity.able -->

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A final effect will be more noticeable from the ground. Anyone lucky enough to live at northern latitudes will find that Sun-fueled geomagnetic storms, which create the colorful Northern and Southern Lights, will actually increase in coming months.

The Sun has rhythm. Beyond its propensity to show up in the East every 24 hours (a rhythm actually dictated by Earth's rotation) there is a deeply rooted cycle of activity within the Sun that increases and decreases every 11.3 years, on average.

This solar cycle, as it is called, is measured by the number of sunspots, tangles of magnetic energy that reflect the overall activity near the surface of the Sun. With more and stronger sunspots come increasingly furious coronal mass ejections -- bubbles of gas and charged particles that are hurled into space and sometimes threaten Earth satellites and power grids.

During the peak in activity, called the solar maximum or solar max, the Sun also releases energy through coronal holes, open magnetic fields that cause sharp increases in the amount of charged particles riding outward on the ever-present solar wind.

David Hathaway, a solar physicist at NASA's Marshall Space Flight Center, began predicting the recent peak in the Sun's activity back in the early 1990s. He had figured it would come in June or July of 2000. Only recently has he been able to look back at the data and figure out where the peak was.

"The maximum sunspot number occurred in July of 2000 and we expect that date to hold," Hathaway told SPACE.com. He said this peak was bigger than average but less dramatic than the previous two.

But as its temper settles, the Sun still has some punch in store.

"Solar flares and coronal mass ejections will decline in frequency with the sunspot number," Hathaway said. "However, geomagnetic storms will continue to increase in frequency due to the high speed solar wind streams from low latitude coronal holes that form late in the solar cycle."

The visible effect will at times be stunning. Earlier this year, a geomagnetic storm sparked aurora -- sheets and filaments of multicolored lights caused by the excitation of gas molecules high in the atmosphere -- that were seen as far south as Texas.

Space weather this weekend squares with the passage of the peak, Hathaway says. A powerful solar flare erupted Saturday at the Sun and sent a coronal mass ejection to Earth that triggered a strong radio blackout on the sunlit side of Earth.

Flares and coronal mass ejections like Saturday's will continue into the future but at a lower rate than a year ago during the solar maximum peak, Hathaway said. "The cycle doesn't show any evidence that we're going to peak again at a higher value than we did last year," he said. "It still looks to me like we passed the maximum."

Earth's atmosphere also undergoes a less visible but still dramatic change during the peak in the solar cycle, one that has a direct impact on anything orbiting the planet.

While more than half of Earth's atmosphere is huddled within 6 miles (10 km) of the planet's surface, the atmosphere extends several hundred miles up, getting ever thinner with height.

During solar maximum, extra doses of the most extreme wavelengths of ultraviolet light heat Earth's upper atmosphere, a region called the thermosphere, which starts at about 60 miles up (100 kilometers). The Space Station and some satellites orbit in the thermosphere.

Though the thermosphere is about a million times less dense than the atmosphere at sea level, it still creates drag on anything orbiting through it. Skylab and Mir are two famous victims of the effect.

During solar minimum, the gas temperature in the thermosphere is around 1,290 Fahrenheit (700 C). But during solar maximum, the temperature can more than double, Hathaway says. The extra heat causes the thermosphere to expand during solar maximum. Denser layers of atmosphere reach higher, and so the region where the Space Station orbits can become 50 times more dense, which increases drag.

In May of last year, amidst the peak in solar activity, the Space Shuttle Atlantis fired its jets while affixed to the Space Station and raised the 35-ton habitat's orbit by 27 miles (43 km). The orbit will decay more than a mile (about 2 kilometers) each year, NASA engineers say. Eventually the Station is to get its own booster system.

Because molecules are far apart in the thermosphere, astronauts cannot feel the incredible heat. In fact, it cannot be measured by normal means, Hathaway says. Instead, scientists use orbital decay to estimate the density of the air, and from this they infer the temperature.