National Geographic : 2012 Jun
• the convection zone, twist and kink and poke through the surface, forming loops made vis- ible by the hot, glowing plasma. When loops cross, they can essentially short-circuit, causing the tremendous plasma explosions called solar ares. Such ares release the energy equivalent of hundreds of millions of megatons of TNT, spewing x-rays and gamma rays into space and accelerating charged particles to nearly the velo- city of light. e Carrington event consisted of a powerful solar are that produced the second of a rare pair of coronal mass ejections (CMEs)---gigantic magnetic eruptions of heated plasma belched into space. The first CME probably reached Earth in a normal span of 40 to 60 hours, clear- ing a path through the solar wind for the sec- ond one to make the trip in a mere 17 hours. eir combined impact squashed the Earth's magnetosphere---where the planet's magnetic eld interacts with the solar wind---down from JUNE 7, 2011 The Solar Dynamics Observatory captured a coronal mass ejection (at four o'clock in all three images) using different wavelengths of light that reflect temperatures in layers of the sun's atmosphere. Temperatures in the relatively cool chromosphere (left) are a mere 90,000 degrees Fahrenheit but rise rapidly to almost two million degrees in the corona above it (center). Why the sun's atmosphere gets hotter farther from its surface remains a mystery. Regions of the corona can rise to more than ten million degrees during solar eruptions (right). NASA SDO helioseismology. Information conveyed by helio- seismic sensors aboard NASA's Solar Dynamics Observatory satellite recently enabled Stanford University researchers to detect magnetic bun- dles 40,000 miles below the solar surface and to predict their emergence, days later, as sunspots. Such data provide crucial information on how solar storms form. e sun functions as a gigantic dynamo, with global magnetic eld lines encircling it from pole to pole like a bird- cage. Local eld lines, entangled with plasma in In the 1859 solar super- storm, charged particles set off intense auroras over much of the Earth. Some people thought their cities had caught fire.