Closest pictures of sun ever taken reveal mysterious 'campfires'
The closest-ever images taken of the sun have revealed mini solar flares called "campfires" dotted across its surface.
The images were captured last month by the Solar Orbiter, a European Space Agency (ESA) probe designed and built in the UK. Scientists say the pictures could shed light on the mysterious process that means the outer layer of the star is so much hotter than the layers below.
The spacecraft came within 47 million miles of the sun's surface and passed between the orbits of Venus and Mercury.
Solar flares are sudden flashes of high-energy radiation from the sun's surface, which can cause radio and magnetic disturbances on the Earth.
Dr Caroline Harper, head of space science at the UK Space Agency, said that scientists were excited by the presence of campfires that are "millions of times smaller than the solar flares".
She said: "We do not really know what they (the campfires) are doing but there is speculation that they might play a role in coronal heating, a mysterious process whereby the outer layer of the sun, known as the corona, is much hotter (around 300 times) than the layers below.
"These campfires may be contributing to that in a way we do not know yet."
The operation was a joint venture between the ESA and NASA.
"In mid-June, Solar Orbiter made its first close pass of the Sun following its Feb 9 launch, turning on all 10 of its instruments together for the first time," NASA said in a statement on its website.
After launching on 9 February, Solar Orbiter made its first close pass of the sun in mid-June, despite the team facing setbacks due to the coronavirus pandemic.
As the spacecraft entered a critical stage of the mission in March, the ESA was forced to close operation centres that had vital measuring equipment and send staff home as the continent went into lockdown.
According to ESA's Solar Orbiter project scientist Daniel Müller, the images will be the closest images of the sun ever captured. "We have never taken pictures of the Sun from a closer distance than this," Müller said.
"There have been higher resolution close-ups, e.g. taken by the four-meter Daniel K. Inouye Solar Telescope in Hawaii earlier this year. But from Earth, with the atmosphere between the telescope and the sun, you can only see a small part of the solar spectrum that you can see from space."
Scientists now hope to find out more by monitoring the temperatures of these campfires using an instrument on the spacecraft known as Spectral Imaging of the Coronal Environment, or SPICE.
The Solar Orbiter will also help scientists piece together the Sun's atmospheric layers and analyse the solar wind, the stream of highly energetic particles emitted by the star.
They hope to be able to eventually make predictions on space weather much like we already do so on Earth.
Severe solar activity has the potential to damage satellites in orbit and disrupt the infrastructure on Earth that mobile phones, transport, GPS signals and the electricity networks rely on.
Dr Harper added: "The science will allow us to start improving our operational capability to predict the space weather, just like you predict the weather here on Earth."
The spacecraft will make a close approach to the Sun every five months, and at its closest will only be 26 million miles away, closer than the planet Mercury.
It will use the gravitational force of Venus and Earth to adjust its trajectory, before getting into operational orbit in November 2021.
Dr Harper said: "At that point, it will send back much more data about the Sun's surface.
"It will also be flying over the poles of the Sun and take images."
The Solar Orbiter was constructed by Airbus in Stevenage and blasted off from Nasa's Cape Canaveral site in Florida on February 10.
It has been designed to withstand the scorching heat from the Sun that will hit one side, while maintaining freezing temperatures on the other side of the spacecraft as the orbit keeps it in shadow.
Dr Harper said: "It is really quite exciting to be involved (in the mission).
"We have leading roles on four of the 10 scientific instruments on board the Solar Orbiter.
"For me, it showcases the UK's world-leading role in solar physics research and its capabilities in the industrial space sector."
- This article first appeared on Yahoo