Scientists identified CME-source and analysed how its magnetic field changes on its path to Earth. Similarly to Earthquakes and the Richter scale, scientists have defined an index (a number) to assess the severity of geomagnetic storm
http://sohowww.estec.esa.nl/data/rea...scription.html
http://www.esa.int/esaCP/SEM5TK808BE_index_0.html
http://sohowww.nascom.nasa.gov/data/...me-images.html
http://sci.esa.int/science-e/www/obj...objectid=37592
Direct measurement by SOHO, ACE and Cluster confirms previous Earth-bound predictions

Strong solar flares have also been seen recently by Cassini and Mars Express, but not this particular one.

Mars Express radar collects first surface data

The first ionospheric measurements performed by MARSIS have also revealed some interesting preliminary findings. The radar responds directly to the number of charged particles composing the ionosphere (plasma). This has shown to be higher than expected at times.

“We are now analysing the data to find out if such measurements may result from sudden increases of solar activity, like the one observed on 14 July, or if we have to make new hypotheses. Only further analysis of the data can tell us,” said Jeffrey Plaut, Co-Principal Investigator, from NASA Jet Propulsion Laboratory, Pasadena, USA.

The Cluster Active Archive Goes Online
http://sci.esa.int/science-e/www/obj...objectid=38705
01 Feb 2006
Today, 1 February 2006, exactly 5 years after the start of scientific operations on the four Cluster spacecraft, the Cluster Active Archive (CAA) goes online.

latest solar data obtained by different SOHO instruments
http://sohowww.nascom.nasa.gov/

Cluster reveals fundamental 3-D properties of magnetic turbulence
24 Feb 2006
Fundamental 3-D properties of magnetic turbulence observed in the magnetosheath are reported, thanks to measurements by ESA's Cluster mission close to the magnetopause. These properties are of prime importance to model magnetic turbulence in the magnetosheath, which plays a key role in the dynamical coupling between the solar wind and the magnetosphere. Their consequences are also relevant to astrophysical and laboratory plasmas. This new scientific breakthrough on magnetic turbulence by Cluster is published today, 24 February 2006, in Physical Review Letters.
http://sci.esa.int/science-e/www/obj...objectid=38841
The Earth's magnetic field is our line of defence against the permanent flow of particles coming from the Sun: the solar wind. Thanks to the Earth's magnetic field, most of this solar material gets deflected around the Earth's magnetosphere, delimited by a boundary layer called magnetopause.
Like for any other magnetised planet (Jupiter, Saturn, ...), the solar wind is in fact first decelerated from supersonic to subsonic speed by a shock wave (called bow shock), located in front of the magnetopause. The region between the bow shock and the magnetopause, characterized by very turbulent plasma, is called the magnetosheath