On March 26, ESA Solar Orbiter made its closest approach to the Sun. It penetrated the orbit of Mercury, where it was hot but totally worth it. The main task of the Solar Orbiter is to understand the connection between the Sun and its heliosphere, and the new images helped to learn more about it.
According to the European Space Agency (ESA), Solar Orbiter is the most sophisticated science laboratory ever sent to the Sun. It is equipped with a powerful set of tools, including a magnetometer, a device for capturing images in extreme ultraviolet light, a plasma analyzer of the solar wind, and other equipment. A wide range of devices allows it to observe solar phenomena in many ways.
It is advantageous for the spacecraft to get as close to the Sun as possible. But as it gets closer, the Solar Orbiter gets hot. The first line of defense of the spacecraft is a thermal shield. It is a multilayer titanium device mounted on a honeycomb aluminum support, with a carbon fiber skin designed for heat dissipation. Between all this and the hull of the spacecraft is another 28 layers of insulation. During this convergence, the heat shield reached a temperature of 500°C.
Protected from the heat, Solar Orbiter collected a lot of data during the rapprochement. Scientists need more time to work with them, but images and videos immediately attract attention. One of the sun’s features that attracted public attention is the “space hedgehog”.
An intriguing detail in the lower third of the image below the center is called the “sun hedgehog”. No one knows exactly what it is and how it was formed in the atmosphere of the Sun.
Thanks to some luck, the Sun staged a show during the Solar Orbiter approach. There were solar flares and even a coronal mass emission (CME) directed at the Earth. Solar Orbiter has several remote sensing tools, and scientists have used them to predict when CME will reach Earth. They published their forecast on social media, and in 18 hours terrestrial observers were ready to witness the aurora borealis.
The orbiter also provided us with images of the Sun’s south pole with the highest resolution.
Scientists are interested in the sun’s poles because of how the sun’s magnetic fields work. Magnetic fields create powerful but temporary active areas on the surface of the Sun and these fields rise and fall to the poles and are then re-absorbed by the Sun. Scientists believe that they are somehow the seeds for the next solar activity. Detailed images of the South Pole of the Sun should help researchers understand how it works.
Solar Orbiter has a lot of interesting things ahead. Over the next four years, the spacecraft will encounter Venus for the fourth and fifth time. Each time its inclination will increase, which will allow it to get a more direct view of the sun’s poles.
These high-latitude observations will allow scientists to see the poles in plain sight. The ESA argues that these observations are crucial to understanding the Sun’s complex magnetic polar environment. This will help unravel the mystery of the 11-year cycles of the Sun.