Scientists resolve 40-year-old Mariner 5 solar wind problemPublished On: Sat, Aug 27th, 2011 | Marine Biology | By BioNews
Scientists led by astrophysicists at the University of Warwick have resolved a 40-year-old problem with observations of turbulence in the solar wind first made by the probe Mariner Five.
The research resolves an issue with what is by far the largest and most interesting natural turbulence lab accessible to researchers today.
Our current understanding tells us that turbulence in the solar wind should not be affected by the speed and direction of travel of that solar wind.
However when the first space probes attempted to measure that turbulence they found their observations didn’t quite match that physical law.
The first such data to be analysed from Mariner 5 in 1971 found a small but nonetheless irritatingly clear pattern in the turbulence perpendicular to both the direction of the travel and the magnetic field the solar wind was travelling through.
While it was an irritating aberration the effect was relatively small and has been essentially ignored by physicists until now.
The new research led by Andrew Turner and Professor Sandra Chapman in Centre for Fusion, Space and Astrophysics at the University of Warwick has found a solution to this 40-year-old problem.
The research team looked at data from the Cluster mission and they also created a virtual model of how magnetohydrodynamic (MHD) turbulence builds up in the solar wind.
“The analysis clearly showed that when all these results were considered together any correlation between changes in the turbulence in the solar wind and the direction of travel simply disappeared,” Turner said.
“The observed non-axisymmetric anisotropy may simply arise as a sampling effect of using just one probe taking a single particular path through the solar wind,” he stated.