PHOBOS-GOES SOFT-X-RAY OBSERVATIONS OF THE SUN

Concurrent observations of solar flares in broadband soft X-rays by tw o dissimilar detectors, one at Mars and one at Earth, enabled a study of the thermal development of disk flares and a study of the gross fea tures of height, thermal stratification, and, in certain cases, the ve locity of expanding flare loops. No normal, impulsive-type flares were observed above 50,000 km, but long-duration hares were sometimes obse rved at greater than 150,000 km. These observations also revealed an u nexpected property of many small-to-moderate flares: cooler plasma is positioned above hotter plasmas throughout the life of the flare.