Our fascination for the sun has prompted mankind to launch a host of solar missions aimed at unraveling its secrets and teaching us more about the giant star that fuels life on our planet. And, while these missions have yielded a treasure trove of data and images, none of them has actually managed to take a look at the sun’s poles.
As Science Alert explains, this is due to Earth’s position on the ecliptic plane around the sun, which keeps all of the planets gravitating around the sun’s equator. Although it is technically possible to veer spacecraft outside of this plane, the task is extremely challenging. For this reason, the majority of robotic probes that we’ve sent to scope out the sun have gotten an eyeful of the sun’s equator, but no glimpse of the solar poles.
In order to even things out, the European Space Agency (ESA) has produced our very first photo of the sun’s north pole. While this is not an actual snapshot taken from above the sun, it is, however, a composite image based on satellite imagery.
The data comes from a tiny European satellite called the PROBA-2. Short for PRoject for OnBoard Autonomy 2, this minuscule spacecraft orbits the Earth and spies on the fiery atmosphere around the sun and the charged particles of solar wind that bombard our planet.
The information gathered by this probe has enabled the space agency to extrapolate on the appearance of the sun’s north pole and to create an artificial image of this solar region. Unveiled by ESA on Monday, the image reveals a hypnotic view of the sun’s north pole — which resembles a “turbulent” vortex, as noticed by Live Science. The photo was made possible thanks to data captured by the extreme-ultraviolet SWAP camera onboard the PROBA-2.
“When spacecraft observe the solar atmosphere, they gather data on everything along their line of sight, also viewing the atmosphere extending around the disk of the sun (the apparent glow around the main disk of the sun, which also extends over the poles),” notes ESA.
All this data can help scientists surmise what the sun’s poles look like even without directly observing them.
The newly released photo showcases the polar coronal hole region or the dark patch in the center of the sun’s disk. This region, which seems to be populated by “a subtle network of light and dark structures,” is responsible for the creation of fast solar wind. These particles streak through space at greater speeds than the solar wind streaming from the sun’s equator.
“This image also shows a bright bulge on the upper-right side of the sun; this is created by a low-latitude coronal hole rotating around the solar disk.”
The only spacecraft to have seen the sun’s poles was the pioneering Ulysses mission — a joint endeavor by NASA, ESA, and the Canadian National Science Council. Launched in 1990, the Ulysses probe flew 200 million miles above the solar poles, or twice the distance between the Earth and the sun. Alas, the spacecraft had no camera to snap a photo of what it was seeing.
ESA’s upcoming mission, the Solar Orbiter, will be much better equipped. Slated to take to space in 2020, the spacecraft will soar high enough above the sun to take a good look at the solar poles.