This one was fun to investigate! My first instinct was that it was a mountain rescue themed stamp, given the rocky backdrop and the helicopter. I was going to stick with it as a wintery theme, given that I’m trying to reach a lot of countries with my Christmas tour. However, a bit of online translation and piecing things together and I give you:
International Year of the Quiet Sun!
1964-65 was a solar minimum, the period in an 11 year cycle when solar activity diminishes, so there are fewer sun spots and solar flares. This makes it quite a helpful time for studying and observation of the sun as there are fewer distractions or things to mess up your readings. The mid-60s solar minimum saw a programme of international cooperation between more than 60 countries to observe and research the sun in various different ways, including ground based observation, rockets and – as shown here – setting up arrays and monitoring stations in remote places such as the poles. This is one of nine stamps showcasing different research methods.