It Just Keeps Going! (March 2, 2007)

This week SOHO observed sunspot 944 coming around the Sun's eastern limb--for the fifth time! Usually sunspots form and dissolve in a matter of days or weeks, but this spot has real longevity-it has survived for an unusually long five solar rotations. Here we put side-by-side images at almost exactly three of the five rotations. The Sun rotates about once every 27 days.

A sunspot receives a new number each time it reappears, so three months ago this was called Sunspot 930 when it blasted out a strong solar flare, one of the strongest in 25 years. Few months ago it was called Sunspot 923. Though the numbers have changed, the spot remains true to its character: a source of magnetic intensity rising from beneath the Sun's surface. Now, though, it is a mere shadow of its former self and poses no threat for such activity.

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.