Ulysses returns to the Sun's south pole and encounters blustery solar weather

Other

Scientific paper

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

Scientific paper

Conditions are very different from those Ulysses encountered during its first south polar pass in 1994 when solar activity, which is related to the magnetic behaviour of the Sun, was very low. Then, the solar wind at high latitudes was fast, but steady. This latest polar pass gives scientists the opportunity to learn just how different the polar regions of the Sun are at solar maximum compared with minimum.
After spending four months above 70o south, Ulysses will swing towards the equator early next year to turn its attention to the northern hemisphere, beginning its passage over the north pole on 3 September 2001. Although it will be travelling the same path it followed six years ago, conditions will be quite different and new discoveries are eagerly awaited.
Since launch in October 1990, Ulysses has already proved one of the most successful interplanetary missions ever. A joint ESA/NASA mission, it is the first spacecraft ever to be launched into an orbit outside the ecliptic, the plane in which the planets orbit the Sun. From this unique vantage point, it has changed our view of the heliosphere, the region of space filled by the solar wind and over which our Sun exerts its influence.
At solar minimum, instruments on board Ulysses found that the fast solar wind, emanating from the Sun's poles, blows at a steady 750 km/s and fills a large fraction of the heliosphere. The state-of-the-art instruments were also able to show that the boundary between the fast wind and the slower, more variable wind from the equatorial regions, is surprisingly sharp. Another surprise was that the effects of collisions, occurring at low latitudes between fast and slow wind streams, continue to be felt all the way up to the poles.
Ulysses discoveries, however, have not been confined to the Sun and heliosphere. Instruments on board the spacecraft also made the first ever measurements of dust particles and neutral helium atoms originating outside the solar system. These findings have contributed to a major increase in our knowledge about the gas and dust clouds surrounding the heliosphere. Other measurements have lead to a better understanding of processes occurring even further away, in distant supernova explosions.
During the relative simplicity of solar minimum, Ulysses made many surprise discoveries. During the relative chaos and unpredictability of solar maximum, many more are expected. Exciting times are ahead in our quest to understand the Sun and its heliosphere.

No affiliations

No associations

LandOfFree

Say what you really think

Search LandOfFree.com for scientists and scientific papers. Rate them and share your experience with other people.

Rating

Ulysses returns to the Sun's south pole and encounters blustery solar weather does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Ulysses returns to the Sun's south pole and encounters blustery solar weather, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Ulysses returns to the Sun's south pole and encounters blustery solar weather will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFWR-SCP-O-765143

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.