The aurora are beautiful, dynamic "space" phenomena appreciated by the general public (as the Northern or Southern Lights).
There are many unsolved scientific
questions about the aurora and their role in the magnetopshere-ionosphere
The Earth's auroral regions are the best
place to study these questions because they are the most accessible (please see the video below, from the space station, courtesy NASA/ESA)
Similar phenomena are expected to occur throughout the universe
in stongly magnetised bodies, thus answers from Alfvén will have wide
What is Alfvén?
Alfvén will explore particle acceleration processes and their consequences for electromagnetic radiation and energy transport in strongly magnetised plasmas.
The mission design involves use of simple virtually identical spacecraft, easily accessible orbits and straightforward operations.
It is a low risk mission that is compatible with the M5 cost cap.
version of the earlier proposal for the ESA M3 competition was published in Experimental Astronomy,
Why a multi-spacecraft mission to the Aurora?
Observations from more than one spacecraft
flying in formation are needed to make progress, building on results from
single spacecraft missions.
The ESA Cluster mission has used four spacecraft to revolutionize our understanding of the magnetosphere.
Now we need to do something similar for the aurora.
Strategic Importance of Alfvén Science
Electromagnetic energy conversion in a low beta plasma is a fundamental plasma physical process that must occur in plasma environments around magnetised bodies throughout the universe.
As well as at Earth, it is expected to be occurring at Jupiter, Saturn and other solar system magnetised planets and most likely many exoplanets.
It is also expected in solar and stellar atmospheres and also in more exotic astrophysical objects such as cataclysmic variables and slowly accreting neutron stars.
The scientific goals of Alfvén are consistent with the scope of ESA´s Cosmic Vision plan.
They are also identified in the US NRC Decadal Strategy Document ¨Solar and Space Physics for a science and technological society¨ (key science goals 2 and 4).
A mission ¨to focus on M-I coupling in the auroral acceleration region¨ has also been recommended for highest priority research in the recent COSPAR Roadmap on the topic ¨Understanding space weather to shield society¨.
ESA's Cosmic Vision 2015-2025
Cosmic Vision is the name of ESA's
programme of scientific research missions.