Preparing for the second close encounter, and thinking back about the first
On Wednesday 10 February 2021, Solar Orbiter will come as 'close' as 74 million kilometers from the Sun. That may sound very far still but it is less than half the distance between the Earth and the Sun (0.49AU), so we will be able to observe our Sun in much more detail. This is the second time during the mission that we reach such a close distance. The first time was in June 2020, at 0.52AU distance, and that was a very special and hectic time. The testing phase of the spacecraft had just finished (see the blog 'Mission Phases') so we had only tried out each instrument during a few short tests. Mid June 2020 we started the so-called Cruise Phase, and during the very first week we had the first close encounter with the Sun! For the first time, all 10 instruments had to take measurements and images at the same time. It was also the first time that they had to prepare all commands for 2 weeks in advance and send them in a special format to the Science Operations Centre, in Spain(*). And on top of that all, the spacecraft and instruments had never been that close to the Sun before! It was a bit stressful for everybody, but it was also a very exciting time! The first real science operations. And it worked!! We got the first images from all the cameras, and good quality measurements from the solar wind sensors onboard. And the best of it all was that we already observed new things on the Sun, things we had not really seen before or not in that much detail.
Have a look at the nice images below. They are from the Extreme Ultraviolet Imager (EUI) onboard: a combination of 3 telescopes that take beautiful images of the solar corona in the same type of light that makes our skin change colour when we are sunbathing. The new things we saw are the tiny white regions that are flickering on the Sun. They look a bit like campfires. Scientists think they are mini solar flares. And that's exciting news!!
In a few days, at the second close encounter, we hope to learn more about these campfires, and take more close-up images. It is a very special encounter because the spacecraft is looking at the back side of the Sun. The Earth and Solar Orbiter are located are opposite sides from the Sun.
To find out where Solar Orbiter is now and will go next: https://solarorbiter.esac.esa.int/where/
(*) The Solar Orbiter Science Operations Centre is located in Villanueva de la Cañada, close to Madrid, and it is there that Anik works, Adriaan's wife.