Materialismo

Scientists want to understand what causes giant explosions in the sun's atmosphere, the corona, such as this one. The eruptions are called coronal mass ejections or CMEs and they can travel towardEarth to disrupt human technologies in space. To better understand the forces at work, a team of researchers used NASA data to study a precursor of CMEs called coronal cavities. Credit: NASA/SolarDynamics Observatory (SDO)

The sun's atmosphere dances. Giant columns of solar material – made of gas so hot that many of the electrons have been scorched off the atoms, turning it into a form ofmagnetized matter we call plasma – leap off the sun's surface, jumping and twisting. Sometimes these prominences of solar material, shoot off, escaping completely into space, other times they fall backdown under their own weight.

The prominences are sometimes also the inner structure of a larger formation, appearing from the side almost as the filament inside a large light bulb. The brightstructure around and above that light bulb is called a streamer, and the inside "empty" area is called a coronal prominence cavity.

Such structures are but one of many that the roiling magnetic fields andmillion-degree plasma create in the sun's atmosphere, the corona, but they are an important one as they can be the starting point of what's called a coronal mass ejection, or CME. CMEs are billion-tonclouds of material from the sun’s atmosphere that erupt out into the solar system and can interfere with satellites and radio communications near Earth when they head our way.

"We don't reallyknow what gets these CMEs going," says Terry Kucera, a solar scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "So we want to understand their structure before they even erupt, becausethen we might have a better clue about why it's erupting and perhaps even get some advance warning on when they will erupt."

Kucera and her colleagues have published a paper in the Sept. 20, 2012,...