Venus and Uranus: Two planets with distinct orbital characteristics

Eric Bebenov. 10/05/2020

Our Solar System has many interesting phenomena that require a wide range of scientific research. An interesting discovery features our neighbouring planet Venus and how it spins in the opposite direction compared to other planets. This unusual rotation that causes Venus to spin westward and clockwise has prompted much debate about the scientific reasoning behind it.

One common theory states that Venus has never actually changed the way it spins. Instead, at one point it could have flipped over 180 degrees because of a strong atmospheric tide caused by the Sun’s gravitational pull on Venus’ atmosphere. Another common theory proposes Venus gradually slowed down until it reversed its direction, due to a combination of the pull of the Sun’s magnetic forces and the impact of atmospheric tides. Initially, it would have been Venus’ atmosphere spinning in retrograde that would provide the rest of the force necessary to move the entire planet in a backwards direction. Neither one of these two theories dominate over the other and thus urges researchers to investigate Venus’ past in search for answers. Tracking the rotation rate and axial tilt, two important dynamics of the planet, can provide support for each of these hypotheses. If the initial rotation rate of Venus was rapid, this would explain the axis-flip mechanism that could have caused the planet to turn 180 degrees. However, if the planet had a relatively small tilt and rotated slower than once every four Earth days, then the other hypothesis of the planet slowing down and reversing can be validated. There are still many models that need to be developed to assist researchers in finding the most probable cause.

In the recent decade, a previously disregarded hypothesis made a comeback. The altered spin of Venus could be attributed to the far beginning of when it was a planetesimal, which is an object formed by rock and dust, in addition to other materials. An object of an almost identical size could have collided with the planet many years ago, causing it to spin in a backwards fashion. Rather than destroying the small size of Venus, they both collided and formed a larger planet.

Venus is not the only planet that has a distinct clockwise spin. Far out into the Solar System, another planet not only has a similar retrograde spin, but also a tilt unlike others. Along its orbital path, Uranus lays 98 degrees on its side when its direction of rotation is taken into account, unlike other planets, which tilt no more than 30 degrees along their axes. Due to this trend, season patterns vary extremely, with each season lasting 21 Earth years. This means that one hemisphere has constant sunlight, while the other has constant darkness during the span of these years. A hypothesis includes a collision between Uranus and another object within the Solar System. What is interesting is how the moons of the planet orbit at the same tilt as its axis, further contributing to the reality of this hypothesis.

Venus and Uranus are two very interesting planets to study, and there is a lot more information that is waiting to be uncovered to solidify any theories regarding these planets. Not only will we be able to learn more about these planets, but new information might allow us to take a look at the Solar System as a whole and explore novel trends.

Cover Photo: (Awarenergy)