Tuesday, September 21, 2021

The Venus unknown strangeness

In the Solar System there is a very special planet, where the day lasts more than a whole year! In fact, Venus completes a revolution around the Sun in 225 terrestrial days, while its rotation period is 243 terrestrial days!

Why Venus takes so long to complete a rotation is still being studied: so far several theories have been formulated, but none of these have been universally accepted.

According to one theory, the rotation was slowed down by the tidal forces that the Sun exerted on the Venusian atmosphere. This is in fact much denser and heavier than the Earth's atmosphere and could have influenced the evolutionary history of the planet.

However, this theory does not take into account that the axis of rotation of Venus is inclined by more than 177° respect to the perpendicular to the plane of the ecliptic. It has therefore been hypothesized that during its formation Venus was hit by another protoplanet, which slowed its rotation and destabilized its axis. Collisions between large bodies were not rare events in the early life stages of the Solar System: let us remember that the Moon was also formed after the forming Earth was hit by a protoplanet.

Credit: ESA, Venus Express.


1 comment:

  1. I think the collision theory is what happened to Venus. It may have started a chain of events which resulted in today's version of Venus.

    ReplyDelete