09 December 2023 - Mission Day: 10235 - DOY: 343
Pick of The Week

Three-Speed CME Action (May 22, 2003)

  • Hi-res TIF image (2.9M)

  • Movies: Quicktime (378K) version.
  • Movies: MPEG (457K) version.
  • Over 18-hour period this last week, three coronal mass ejections (CMEs) from three different points of origin erupted on the Sun (May 19, 2003). What is interesting to note is that the leading edge of each cloud of particles blasts away from the Sun at distinctly different speeds. The first one (ten o'clock position) represents the middle speed: although its front moves to the edge of the image in about two hours, it is trailed by strands of particles for several more hours. The second and slowest CME (two o'clock) takes the full 18-hour period to develop and trudge along to the frame's edge. The last CME (seven o'clock) is the fastest, with its well-defined, bulbous front rushing the to the edge of the C2 image in less than two hours.

    With the C2 field of view measuring six solar radii, scientists can project an estimated speed of the CMEs. The slowest CME appears to be moving at about 45 kilometers per second (km/s), considered quite slow; whereas the fastest one appears to be moving at about 400 km/s. The real speed could be much higher if it is moving at an angled plane from our line of sight. Most CME particle clouds, if headed towards Earth, would arrive at Earth in about two to four days.

    It is believed that none of these will have a direct impact of Earth's magnetosphere because they were directed elsewhere in space.

    Previous Picks of the Week

    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.


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