WISE update, an aurorae update, and turbulence in the solar wind

6 Oct 2010

At www.jpl/nasa.gov/news/ October 5th (see also Science Daily and www.physorg.com/print205433228.html ) ... as the WISE mission approaches the end of its life NASA announces that so far it has discovered 19 comets, 33,500 asteroids, and 120 Near Earth Objects. NEOWISE will extend the mission for a while longer but will concentrate on the brown dwarfs and other little known cosmic bodies.

At www.physorg.com/205411102.html there is a piece on aurorae that seem to flick on and off at the poles - which over the years has puzzled observers. Why does it happen? NASA thinks it now knows the answer - the earth is like a giant magnet and magnetic lines arch from pole to pole. This magnetic field protects life on earth from the solar wind - which is swept away. This process creates a burst of electro-magnetic energy, likewise. Old time walkie talkies used to suffer from up and down waves - created by lightning. These waves interact with electrons in the magnetic field and knock them down into the atmosphere to create the pulsating auroral light show in a similar fashion to a cathode tube creating images on a television screen (published in October's Science magazine).

At www.physorg,com/print205430543.html ... a report on the joint ESA/NASA Cluster Mission that is studying the surface of the Sun has shown it to be an uruly ball of hot gas that periodically expels plumes of plasma into space - but there is more going on. Surrounding the Sun is a roiling wind of electrons and protons that is constantly turbulent and long streaming jets, smaller whirling eddies, and even microscopic movements are taking place as charged particles circle in miniature orbits. In the midst of it all great magnetic waves and electric currents move around stirring the pot even further (see article in Physical Review Letters September 24th). The solar wind is much hotter than expected - some million degrees Celsius, and it can move extremely fast, 750km  a second. It seems that Alfven waves play a role - perpendicular waves that create electrical fields that efficiently transfer energy to particles, pushing them to move faster.