Call it Cosmic TV . As if watching the biggest of big screens, scientists used a vast cloud of hydrogen atoms in the solar system to monitor the reflection of solar hot spots emanating from the back side of the Sun . The technique, announced yesterday, may one day allow better forecasting of space weather, which can affect satellites and other communications systems on Earth. The Sun's ultraviolet radiation as seen reflected against a cloud of hydrogen atoms in space.
Brighter areas indicate more radiation.
As the Sun rotates through the sky in a roughly 28-day cycle, these hot spots gradually appear on the left side of the Sun, eventually rotating into full view and possibly causing expulsions of radiation that can threaten Earth. Just like the rotating searchlight, the Sun's rotation causes the reflection of ultraviolet emissions to move against the hydrogen cloud. Solar activity increasing The Sun is currently in the midst of its rise toward a peak of sunspot activity. The next solar maximum, as the events are known, may arrive late this year or early next year, researchers said earlier this month . At the maximum, the Sun will bombard Earth's atmosphere with extra doses of solar radiation.