The first images from Solar Orbiter, a new Sun-observing mission by the European Space Agency (ESA) and NASA, have revealed miniature solar flares, dubbed ‘campfires’, near the surface of our closest star.

According to the scientists behind the mission, seeing phenomena that were not observable in detail before hints at the enormous potential of Solar Orbiter, which has only just finished its early phase of technical verification known as commissioning.

Solar Orbiter, which launched on 10 February 2020, carries six remote-sensing instruments, or telescopes, that image the Sun and its surroundings, and four in situ instruments that monitor the environment around the spacecraft. By comparing the data from both sets of instruments, scientists will get insights into the generation of the solar wind, the stream of charged particles from the Sun that influences the entire Solar System.

The unique aspect of the Solar Orbiter mission is that no other spacecraft has been able to take images of the Sun’s surface from a closer distance.

Prof Peter Gallagher, Head of Astrophysics at the Dublin Institute for Advanced Studies and Lead Developer for the SFI supported Irish Low Frequency Array (I-LOFAR), is co-investigator on the Solar Telescope Imaging X-Rays (Stix) instrument, one of six scientific instruments which will observe the sun and send imagery to Earth. “ESA’s Solar Orbiter was launched from Kennedy Space Centre in February 2020 carrying onboard a suite of scientific instruments to study solar activity and its impacts on Earth” said Prof Gallagher. “The spacecraft is already taking images of the Sun with better resolution and sensitivity than any previous mission and Irish scientists and engineers have made significant contributions. My team at DIAS and Trinity College Dublin have been involved in writing software for the STIX X-ray imager onboard the spacecraft. This has been led by Dr Shane Maloney, an expert in space missions and software development.”

Irish company Enbio have also been responsible for developing mission critical coatings to protect the spacecraft from temperatures in excess of 500 degrees Celsius in the inner solar system, while Irish software company CAPTEC were responsible for testing the satellite’s software to ensure that it performs as expected. The ESA activities of Prof Gallagher’s team are supported by the ESA/PRODEX programme and Enterprise Ireland. 

Solar Orbiter is a space mission of international collaboration between ESA and NASA. Nineteen ESA Member States (Austria, Belgium, the Czech Republic, Denmark, Finland, France, Germany, Greece, Italy, Ireland, Luxembourg, the Netherlands, Norway, Poland, Portugal Spain, Sweden, Switzerland, and the United Kingdom), as well as the USA’s National Aeronautics and Space Administration (NASA), contributed to the science payload and/or the spacecraft.

“The first data are already demonstrating the power behind a successful collaboration between space agencies and the usefulness of a diverse set of images in unravelling some of the Sun’s mysteries,” comments Holly Gilbert, Director of the Heliophysics Science Division at NASA Goddard Space Flight Center and Solar Orbiter Project Scientist," said Prof Gallagher.

Dr David Long (UCL Mullard Space Science Laboratory), Co-Principal Investigator on the ESA Solar Orbiter Mission EUI Investigation, said: "No images have been taken of the Sun at such a close distance before and the level of detail they provide is impressive. They show miniature flares across the surface of the Sun, which look like campfires that are millions of times smaller than the solar flares that we see from Earth. Dotted across the surface, these small flares might play an important role in a mysterious phenomenon called coronal heating, whereby the Sun's outer layer, or corona, is more than 200 - 500 times hotter than the layers below. We are looking forward to investigating this further as Solar Orbiter gets closer to the Sun and our home star becomes more active."