NASA Astronomy Picture of the Day Collection

S is for Sun

Taken yesterday from the SOHO spacecraft, this false-color image shows [ http://sohowww.nasc…Sun_Obs.html ] the active Sun near [ http://www.athropol…] the March Equinox [ http://www2.worldbo…feature=seasons&page =html/seasons.htm&di rect=yes ], the beginning of Autumn in the south and Spring in the northern hemisphere. Recorded [ http://sohowww.nasc…latestimages.html# ] in a band of extreme ultraviolet light emitted by highly ionized iron [ http://antwrp.gsfc.…] atoms, the Sun's upper atmosphere or solar corona [ http://science.msfc…corona.htm ] shines with an array of active regions and plasma loops suspended in magnetic [ http://science.msfc…the_key.htm ] fields. The bright coronal structures and loops seen here have temperatures of about 1.5 million kelvins [ http://antoine.fsu.…why-273.15-kelvin.sh tml ]. By chance, the Sun's earth-facing [ http://antwrp.gsfc.…] side also seems to be marked with a twisting complex of dark filament channels [ http://sohowww.nasc…filament.html ] shaped like a giant "S". Filaments represent relatively (!) cool material in the corona which show up as prominences when seen at the Sun's edge. For planet Earth, recent [ http://spaceweather…] solar activity has made auroral displays likely around this year's March Equinox [ http://antwrp.gsfc.…].

SOHO [ http://sohowww.nasc…] - EIT Consortium [ http://umbra.nascom…], ESA [ http://www.esrin.es…], NASA [ http://www.nasa.gov/]

sun

photosphere

magnetic field

corona

equinox

prominence

filament

Goddard Space Flight Center (GSFC)

Marshall Space Flight Center (MSFC)

Earth

Sun

SOHO

YES

http://antwrp.gsfc.…

SPD-APOD-ap020321