Mercury transit seen by Solar Orbiter.
The tiny sizes of the various planets, including Earth, in front of the sun have been depicted in various graphics and illustrations made by experts, but a spacecraft studying the irrational behaviour of our magnificent sun recently captured an event rarely visible from our location here on the surface of the Earth.
The Solar Orbiter, operated by the European Space Agency, captured the transit on January 3, 2023, during which Mercury looked like a perfectly black circle travelling over the Sun's surface.
About identical in size to the Moon, Mercury is the smallest planet in our solar system. Mercury is the fastest planet, zipping around the sun every 88 earth days.
According to the ESA, in the Polarimetric and Helioseismic Imager (PHI) image, Mercury is seen as a black circle in the lower right quadrant of the image. It is distinctly different from the sunspots that can be seen higher up the sun's disc.
"The Extreme Ultraviolet Imager (EUI) took a movie of the planet's progress. In particular, it showed Mercury just after it had left the disc and was silhouetted in front of gaseous structures in the sun's atmosphere," the European Space Agency stated.
"It's not just looking at Mercury passing in front of the Sun, but passing in front of the different layers of the atmosphere," says Miho Janvier, Institut d'Astrophysique Spatiale, France, the SPICE deputy project scientist who is currently on secondment to ESA.