A dark, snaking line across the lower half of the sun in this Feb. 10,
2015 image from NASA's Solar Dynamics Observatory (SDO) shows a filament
of solar material hovering above the sun's surface. SDO shows colder
material as dark and hotter material as light, so the line is, in fact,
an enormous swatch of colder material hovering in the sun's atmosphere,
the corona. Stretched out, that line – or solar filament as scientists
call it – would be more than 533,000 miles long. That is longer than 67
Earths lined up in a row. Filaments can float sedately for days before
disappearing. Sometimes they also erupt out into space, releasing solar
material in a shower that either rains back down or escapes out into
space, becoming a moving cloud known as a coronal mass ejection, or CME.
SDO captured images of the filament in numerous wavelengths, each of
which helps highlight material of different temperatures on the sun. By
looking at such features in different wavelengths and temperatures,
scientists learn more about what causes these structures, as well as
what catalyzes their occasional eruptions. Image and caption courtesy of NASA (all rights reserved). |
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