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| Here Comes the Sun - trio of Solar Flares |
| 日期:2003-11-05 14:36 编辑: system 来源： |
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Here comes the sun. Again and again and again. Just days after two monster solar hurricanes sped toward Earth, the sun lobbed a trio of solar flares into interplanetary space on Monday.
The sun is seen in this November 3 image from the SOHO satellite's Extreme Ultraviolet Imaging telescope. [NASA]
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These latest flares carried enough electrically charged particles to cause concern for some satellite operators on Earth, but are likely to have less impact on our planet than last week's huge solar storms.
That is because the storms that hit Earth last Wednesday and Thursday, some of the most intense ever detected, were aimed right at our planet. The latest storms are not.
By Monday, the giant region of sunspots that is spawning the flares had rotated far to the right edge of the circle of sun that is pointed at Earth, which means any flares it generates will go off into space.
But they may still produce auroras that will be visible in Earth's temperate middle latitudes, according to scientists monitoring the SOHO spacecraft that keeps watch over solar weather.
This particular spate of space weather springs from a sprawling cluster of sunspots 200,000 miles across that has been slowly moving across the surface of the sun that we can see for the last two weeks.
Sunspots frequently cause solar flares and their more disturbing offspring, coronal mass ejections, but this sunspot group is atypical, said Aad van Ballegooijen, a scientist at the Harvard-Smithsonian Center for Astrophysics.
"Earth would be smaller than one of the sunspots in this group," van Ballegooijen said, to convey the group's vast size. Beyond mere size, though, this group has a scrambled magnetic field that is highly unusual, he said by telephone.
Most sunspot groups are bipolar, with positive and negative charges clashing and producing charged particles that sometimes find their way to Earth.
This group, however, is what might be called tripolar, with positive, negative and positive charges battling it out. It is unclear if there is a second negative charge lurking in the group.
For now, though, the whole group is rotating away from Earth to the side of the sun that faces away from us. It could be back in a few weeks, van Ballegooijen said.
"It may come back a few weeks from now or it may not," he said. "It will have changed quite a bit, (the sunspots) might not be as big, that is generally what happens." |
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