In June, the European Space Agency’s (ESA) Solar Orbiter took its first images of the Sun, and now these stunning images have been unveiled. These are the closest images of the Sun humanity has ever taken. The spacecraft was at its closest point to the Sun yet when they were taken, roughly 77 million kilometers (48 million miles) away.
“No images have been taken of the Sun at such a close distance before and the level of detail they provide is impressive,” Dr David Long of the UK's UCL Mullard Space Science Laboratory, and Co-Principal Investigator on the ESA Solar Orbiter Mission EUI Investigation, said in a statement.
The images have revealed a new phenomenon, dubbed "campfires," near the surface of the Sun.
“They show miniature flares across the surface of the Sun, which looks 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,” Long said.
This first-light image and the scientific analysis conducted, including measurements of Comet ATLAS's tail as it swung by, were part of the team's testing of the spacecraft's 10 science instruments to make sure everything was working properly. Tests will continue regularly until the spacecraft gets into its operational orbit in November 2021. Then, its close passage will take it as near as just 42.5 million kilometers (26.4 million miles) from the Sun.
The data announced today includes so much more than these incredible images, though. Detailed spectroscopic analysis of the Sun was collected by the instruments, as well as information on the chemical composition of the solar wind, the stream of particles released by the Sun. The mission scientists are already analyzing the interesting magnetic data, already indicating the complexity of the magnetic fields inside and around the Sun. Perhaps the most exciting thing of all is that this is only the beginning of the mission.
“These are only the first images and we can already see interesting new phenomena,” Daniel Müller, ESA’s Solar Orbiter Project Scientist, said in a statement. “We didn’t really expect such great results right from the start. We can also see how our ten scientific instruments complement each other, providing a holistic picture of the Sun and the surrounding environment.”
These images are not the highest-resolution pictures of the Sun; those were taken by the 4-meter Daniel K. Inouye Solar Telescope in Hawaii earlier this year. But as the Solar Orbiter is not on the ground, it hasn't got Earth's atmosphere in the way so can produce more complete images of the Sun.
"These new images are very exciting because they are the closest pictures we have been able to take of the Sun up to now," Dr Caroline Harper, Head of Space Science at the UK Space Agency, told IFScience. "These new discoveries are a piece in the jigsaw about how the Sun works and how it generates its solar wind which causes space weather which can impact on the satellites we rely on so much in our every day lives."
The goal of this mission, over its several years of operation, will be to study the Sun like never before, including taking the first images of the Sun’s poles. This will be possible thanks to several flybys around Venus. The team will use the gravity of the planet to shift the orbit of the spacecraft, eventually rising to 33 degrees from the plane of the Solar System, a crucial vantage point from which point it will be possible to see the polar regions of the Sun.