4.12.2018

This view of the sun’s north pole was stitched together from other images

ESA/Royal Observatory of Belgium

Here’s a view you’ve never seen before. Detailed images of the sun in all its blazing glory – with coronal loops, sunspots and solar flares – have become common, thanks to the small fleet of sun-watchers that orbit the inferno. But all of these craft snap the sun from the side, never from above or below.

To get this view of the sun’s north pole, the European Space Agency engaged in some clever camera trickery using images shot by its Proba-2 solar explorer.

ESA took strips from the edge of the sun, capturing the behaviour of its atmosphere in the northern hemisphere, and then stretched them out and laid them flat to approximate a view from above. By repeating this process as the sun rotated, building up more and more strips, they were able to estimate what the unseen polar surface looked like.

You can see this trickery in the image if you look closely. The black lines are strips from images taken while Proba-2 was looking away from the sun. The discontinuity across the middle is there because the sun’s atmosphere changed while the image was being constructed.

Despite being a mock-up, the result could shed light on some of the sun’s secrets, such as how coronal holes and ejections form. Still, to study the poles properly, researchers will have to wait for the launch of ESA’s Solar Orbiter in 2020.

This will be the first polar explorer since the joint NASA/ESA Ulysses probe, which flew over and under the sun in 1994 and 1995. Without a camera, Ulysses was unable to take any holiday snaps, however.

Quelle: NewScientist