This composite image from the ESA-led Solar Orbiter mission showcases the Sun observed across eight different wavelengths, each revealing distinct layers and temperatures of the solar atmosphere. The top row presents the Sun’s photosphere in visible light, a magnetic field map, and the corona in extreme ultraviolet. The bottom row spans ultraviolet observations from 10000 °C to over 1.2 million °C, highlighting emissions from hydrogen, carbon, oxygen, neon, and magnesium. These multi-wavelength views help scientists understand the Sun’s complex structure and dynamic behavior across its outer layers. Click image to enlarge. Credit: ESA
Alessandra Giunta
Abstract
In Spring and Autumn 2025 Solar Orbiter observed the poles of the Sun from an out-of-ecliptic position, centred at heliographic latitudes of about 16.8 degrees, using its full suite of remote sensing instruments. This allowed the Spectral Imaging of the Coronal Environment (SPICE) instrument to record the first ever extreme ultraviolet spectral observations of the Sun’s surface at the poles.
SPICE made direct spectroheliograms of the South and North polar regions at selected wavelengths, ranging from the solar upper chromosphere to the corona. This enables the analysis of the physical state of the emitting plasma from the different layers of the solar atmosphere, using a core set of emission lines, formed over a wide range of temperatures from 20 000 K to 0.6 MK, and arising from ions of elements such as hydrogen, carbon, nitrogen, oxygen, neon, magnesium, sulphur, argon and iron.
Additional global campaigns, known as full disk mosaics, were carried out from heliographic observing latitudes of about 15.2-15.9 degrees, allowing SPICE to record spectra from the whole Sun in under 12 hours. In synergy with other Solar Orbiter instruments, specifically EUI, PHI and Metis, such observations allow a full coverage of the emission from the solar surface, tracking from the limb into the heliosphere from a different perspective.
This work will give an overview of these novel observations, focusing on the study of the intensity maps made with isolated transition regions and coronal lines, to investigate the plasma status at the poles. A preliminary analysis of the behaviour of the solar composition in the polar surroundings is also presented.