The Solar Orbiter spacecraft of the European Space Agency and NASA shows us the Sun as we have never seen it before. Powerful flares, stunning views of the solar poles and a curious solar “hedgehog” are among the spectacular images, movies and data obtained by the probe during its first approach to the Sun.
Solar Orbiter’s closest approach to the Sun, known as perihelion, took place on March 26. The spacecraft came within about 30 million miles, within Mercury’s orbit at a third of the Sun’s distance from Earth. At that distance the temperature reaches 500°C, but its advanced technology allowed it to stay safe and the spacecraft managed to record our star in truly impressive detail.
As explained by the ESA in the video description, these images were taken by the Extreme Ultraviolet Imager on March 27, 2022, and show the Sun at a wavelength of 17 nanometers. This is the wavelength that gas emits at a temperature of about a million degrees, which corresponds to the temperature of the Sun’s outer atmosphere, the corona.
The movie first shows the full Sun, with magnetism pouring out from the Sun’s interior to trap glowing loops of coronal gas. Subsequently, coronal loops can be seen on a smaller scale. The color in this image has been artificially added because the original wavelength detected by the instrument is invisible to the human eye.
Four days after the spacecraft passed its closest point to the Sun, on March 30, 2022, Solar Orbiter looked at the Sun’s south pole, as seen in the video below. These images were recorded by the Extreme Ultraviolet Imager (EUI) at a wavelength of 17 nanometers.
In the video description, ESA collaborators explain that the brightest areas of the image are mostly created by loops of magnetism rising upwards from the solar interior. They are called closed magnetic field lines because particles have a hard time passing through them and become trapped, emitting the extreme ultraviolet radiation that the EUI is specially designed to record.
On the other hand, the darkest areas are regions where the Sun’s magnetic field is open, so gases can escape into space, creating the solar wind. In the same way as the first video, color has been artificially added because the original wavelength detected by Solar Orbiter’s instrument is invisible to the human eye.
“The images are really impressive”, said in a statement David Berghmans, of the Royal Observatory of Belgium, and Principal Investigator (PI) of the Extreme Ultraviolet Imager (EUI) instrument.
On March 25, 2022, one day before Solar Orbiter’s closest approach to the Sun, the spacecraft recorded how a solar flare created a huge disturbance in the Sun’s outer atmosphere, the solar corona, causing the launch of a large amount of gas into space in a coronal mass ejection.