Holes in Sun
Above: Escaping gas coloured blue. SOHO (ESA & NASA) SUMER on EIT background
Scientists working on data gathered by the SUMER spectrometer aboard SOHO found the birthplace of the fast solar wind at the corners of honeycomb-shaped magnetic fields surrounding the edges of large bubbling cells located near the Sun's poles. "The identification of the detailed structure of the source region of the fast solar wind is an important step in solving the problem of solar wind acceleration," said Klaus Wilhelm of the Max-Planck-Institut für Aeronomie in Lindau, Germany, principal investigator for SUMER. "We can now focus our attention on the gas conditions and the dynamical processes seen in the corners of the magnetic field structures."
Above: Klaus Wilhelm (painting by Georg Siebecke, 1987), principal investigator for SUMER.
Since 1996 the European Space Agency has had a two-tonne watchdog for storms in the Sun that may affect the Earth. Its name is SOHO, short for Solar and Heliospheric Observatory, and it is a project of international cooperation between ESA and NASA. Virtually suspended in a spot 1.6 million kilometres from our planet, SOHO has kept a lot more than one eye on our turbulent star. Its twelve instruments have observed from the depths of the Sun's core, to the cataclysms on its surface, to the fiery tempests in its atmosphere and to the tenuous, yet far-reaching solar wind.
Above: SOHO (Illustration by Steele Hill)
Scientists are still debating whether an almost complete lack of sunspots around AD 1700 (known as the Maunder Minimum) may have caused a little ice age on Earth. Some think that cloud cover on our planet might be affected by the interaction between the Sun's magnetic field and cosmic rays from deep space.
"If we can get data from SOHO throughout the coming solar maximum, we might learn enough to begin to draw conclusions about the effects of solar activity on the climate of our own planet," said the Norwegian solar physicist Pel Brekke, of the Institute for Theoretical Astrophysics in Oslo and SOHO's deputy project scientist.
Above: Pel Brekke, SOHO's deputy project scientist.