A Pair of CMEs (November 26, 2002)
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SOHO's LASCO C2 instrument observed two coronal mass ejections (CMEs)
over an 18-hour period 24-25 November 2002. A comparison of the two
suggests two rather different kinds of events that seem to originate
from the same region. The first CME appears and disappears from the
field of view rather suddenly, within about four hours. And, its
fainter cloud of particles extends across a wide area. The second
tighter and brighter CME takes much longer to brighten and gather
itself before finally surging away in the 9:54 UT frame. The source
of the first CME was an eruptive prominence clearly seen lifting off
from the surface in the extreme ultraviolet (EIT 195) movie for the
area over a six-hour period. The source of the second CME is not
clear, though neither CME appears likely to impact the Earth. CMEs eject a billion tons of particles traveling one to two millions of miles an hour. The dark disk blocks the Sun so that the LASCO instrument can observe the structures of the corona in visible light - structures a billion times fainter than the disk of the Sun.
SOHO began its Weekly Pick some time after sending a weekly image or video clip to the American Museum of Natural History (Rose Center) in New York City. There, the SOHO Weekly Pick is displayed with some annotations on a large plasma display. If your institution would also like to receive the same Weekly Pick from us for display (usually in Photoshop or QuickTime format), please send your inquiry to steele.hill@gsfc.nasa.gov. |