During early 2012 unique conjunctions of the terrestrial planets occurred along the solar wind Parker spiral, involving initially Mercury, Earth and Mars, and later Venus and Mars in perfect alignments. At the same time the solar activity had picked up rather fast, following the extreme solar minimum lasting until 2010, and several strong CIRs, solar flares and CMEs were encountered during the period of planetary conjunctions.
The constellations of spacecraft around Mercury (Messenger), Venus (Venus Express), Earth (ACE, Wind, SDO) and Mars (Mars Express) in conjunction with MSL en route to Mars, and Stereo A and B located "behind" the Sun, allow for unique studies of development of disturbances in the inner heliosphere and comparative planetary responses to such disturbances.
We invite single or multiple spacecraft studies and/or model results from events during this unique period of conjugated instrumentation.