Ulysses Records Solar Disturbance

Disturbed solar conditions will be observed by the European Space Agency's Ulysses spacecraft which is making its second reconnaissance six years after it's first pass over the sun's poles.

After spending four months flying over the sun's south region, the spacecraft swung towards the equator to observe the luminary's northern polar expanses. The robotic explorer's observations, now in their 11th year, are expected to reveal solar storms and chaotic solar winds.

Observations on Ulysses confirm that the interplanetary medium is filled with a complex tangle of magnetic field lines which play a role in the phenomena. The high level of fluctuations in the magnetic field that is responsible for restricting the influx of cosmic rays - highly energetic particles travelling at nearly the speed of light - into our solar system was also discovered.

Solar activity has been increasing and Ulysses has started observing more disturbed conditions at increasing solar latitudes. Instead of coronal holes covering the polar regions, hot and active regions are generating a surprising amount of disturbance over the whole sun.

The magnetic field observations already show that at its present high-activity level, the sun throws large amounts of exploding coronal material into space at all latitudes. Observations reveal that the previously detected high levels of fluctuations have given way to compressed and tangled magnetic structures, remnants of the exploding coronal loops. Cosmic rays now have an even harder time penetrating into the solar system.

Researchers can still look forward to another four years of operation on Ulysses until it completes its second orbit around the sun in 2004. By the time the mission comes to an end, the spacecraft will have gathered the only set of observations above the solar poles covering more than a complete 11-year solar cycle.