Artist’s impression of the European probe Solar Orbiter, whose launch is foreseen in February 2020.

Perform a CT scan of the Sun’s atmosphere from a distance less than that of Mercury, in order to have more precise indications for space weather, and to study how the activity of our Star, starting from the solar wind, influences the life on the Earth and in space. These are the main objectives of Solar Orbiter, a European Space Agency (ESA) and NASA joint mission presented by ESA to the Italian scientific community in an info day organised by the Italian Space Agency (ASI).

The mission, which will last about seven years, is part of the ESA Cosmic Vision 2015-2025 scientific program. The launch is scheduled on the night between February 5 and 6, 2020, from the Cape Canaveral base in Florida (US) with an Atlas V rocket. Very important is the Italian contribution with ASI, the National Institute for Astrophysics (INAF), universities and industry.

“Solar Orbiter will study how the Sun controls the heliosphere, the invisible bubble in which the star projects its effects on our planetary system, analysing for example sunspots and solar flares,” explained Denise Perrone, ASI, who’s working on the Solar Wind Analyser (SWA), one of the ten instruments of the Solar Orbiter payload, that will study the solar wind.

In order to catch the breath of the solar wind, Solar Orbiter will fly as close to the Sun as about 42 million kilometres, even closer than Mercury’s orbit. For example, it will be able to “observe the poles of the Sun for the first time,” explained Marco Stangalini, ASI, project scientist of the Metis coronagraph. Metis has been designed and built at the Thales Alenia Space (Thales-Leonardo) industry in Turin, to study the solar corona. “The solar corona is – he said – the region where the solar wind originates and is accelerated. We can consider the corona as the atmosphere of the Sun.”

Protected by a heat shield, also built by Thales Alenia Space, which keeps the spacecraft safe from solar radiation almost 13 times higher than that received by the Earth and temperatures above 500 degrees, Solar Orbiter’s suite of instruments will also provide impressive images of the surface of the Sun, with a resolution never achieved before. Thanks also to the Metis coronagraph that, concludes Stefano Cesare, Thales Alenia Space, “will block the light of the solar disk, creating an artificial eclipse as the Moon does, allowing us to look in detail at what happens in the Sun’s corona.”