Why do planets orbit the Sun counterclockwise? A simple explanation of a complex phenomenon.

If you were to look down on the Solar System from above the Sun's north pole (just imagine that such a viewpoint is possible), you would see all the planets revolving around the central star in a counterclockwise direction. This has been the case since the time when all celestial objects in our galaxy were just beginning to form.

According to scientists, the Sun was born from a cloud of dust and gas that resulted from the collapse of a small portion of a gigantic interstellar molecular cloud, which emerged after the explosion of a neighboring supernova. Most of the material formed a star—a yellow dwarf—composed of 91% hydrogen and 8.9% helium. The remnants that did not form a star created a rotating protoplanetary disk, from which planets, their moons, asteroids, and other small celestial bodies eventually formed.

As this gas-dust cloud began to contract, its center—the Sun—started to rotate. This rotation initiated in a counterclockwise direction, and scientists find it challenging to explain why it started in that direction rather than the opposite.

Interestingly, in addition to the external rotation of the Sun, there is also its internal—differential rotation, which occurs due to nuclear reactions. This process was only modeled in 2021 when the Japanese supercomputer Fugaku simulated thermal convection and magnetic fields within the star. This demonstrated that the equator of the star rotates much faster than its poles.

In ancient times, scholars believed that in the Solar System, it was not the planets that revolved around the Sun, but rather the Sun that revolved around the Earth. This argument was systematically debunked by Nicolaus Copernicus, who developed a heliocentric model that convincingly demonstrated that the Earth is not the center of the universe. According to his idea, all planets orbit the Sun along their respective paths.

The direction of the planets' movement is influenced by the conditions under which they were formed. Factors such as turbulence caused by supernova shockwaves and magnetic effects that arise when parts of the gas-dust cloud begin to coalesce into celestial bodies affect the final angular momentum and direction of their rotation. These interactions can be quite complex, and it is likely due to these factors that the rotation occurs counterclockwise.

In our Solar System, there are two peculiar objects that move somewhat differently from the other planets. Uranus is tilted on its side and rotates on an axis that is nearly parallel to the plane of its orbit, making it difficult to determine the direction of its rotation.

On the other hand, Venus rotates on its axis, which is tilted at 177.36° to the orbital plane, giving the impression from the northern pole that it rotates in the opposite direction. This phenomenon is known as retrograde motion—a type of planetary movement where, when viewed from Earth, it appears as if the body is moving backward. This occurrence, by the way, can happen with all planets in the Solar System. More details on this can be found here.

These peculiarities are believed to have been caused by various collisions of celestial objects that took place during the formation of the Solar System.

If we were to imagine that during the formation of the Solar System, the central star and the surrounding planets began to rotate in the opposite direction, it would not have impacted our lives. However, if Earth were to suddenly stop rotating, or even reverse its rotation, then significant consequences would be unavoidable.