1. Birth of PNST: National programme on Solar Terrestrial Relations Why did we propose PNST, a joint venture between the solar and the magnetospheric community? Key role of Alan; the first chairman!

2. Why did we propose PNST ? The activity in the solar corona has a direct influence on the ionized environment of the Earth. The corona, the solar wind and the magnetosphere-ionosphere form a complex system that reacts to solar activity. Solar and magnetospheric communities share the same theoretical tools: plasma physics. Yet, 15yers ago, collaborations were quite rare because experimental tools are very different.

3. The expected participations in Solar Orbiter and Solar Probe missions were offering new opportunities to combine remote sensing and in situ instruments on a single platform, with new scientific prospects. There was a wish from INSU to structure the astrophysical community and to establish ackowledged evaluation bodies. I contacted Alan, who was the obvious partner, to propose and build a joint programme on Solar Terrestrial physics. His deep knowledge of plasma physics helped a lot. Alan was unanimously elected chairman of the scientific committee. He was very active at promoting the programme.

4. Tribute to a talented chaiman I call up with pleasure the 6 years we worked together. The collaboration with Alan was always fruitful and friendly. There were never any (magnetic) cloud between us; we always found a « gentleman » agreement. Alan was exceedingly clever at solving delicate problems within the community. He should have a magic recipe…maybe his slight accent. Anyway, thanks to his wise advices PNST has been put on the right tracks and (still) has a high visibility.

5. Among others I remind some suggestions Alan made several times : do not prepare too much your talks…you will loose spontaneity! I leave it to you to decide if I followed his advice!

6. Examples of joint works Theoretical (including simulations) and experimental works on plasma turbulence in particular in the Solar Wind (IAS, Nice, LPP and LESIA) « Ateliers» on reconnexion and shocks. Collaborations on SO and SP probes that implement both in-sitù and remote sensing instruments.