 Image: NASA |
Our neighboring planet Venus is an oddball in many ways. For starters, it spins in the opposite direction from most other planets, including Earth, so that on Venus the sun rises in the west. Not that it happens often: a day there lasts a little more than 243 Earth-days, actually making it longer than a Venusian year, which is only about 224 Earth-days long.
Many scientists believe that the long days are a result of the sun's strong pull on the planet. (Mercury, which is even closer to Sol, has fairly long days as well: three for every two Mercury-years). But scientists are still puzzled by Venus's retrograde, or backward, rotation. Now a team of scientists from the French research institute Astronomie et Systemes Dynamiques have proposed a new explanation, published in this week's issue of Nature.
Current theory holds that Venus initially spun in the same direction as most other planets and, in a way, still does: it simply flipped its axis 180 degrees at some point. In other words, it spins in the same direction it always has, just upside down, so that looking at it from other planets makes the spin seem backward. Scientists have argued that the sun's gravitational pull on the planet's very dense atmosphere could have caused strong atmospheric tides. Such tides, combined with friction between Venus's mantle and core, could have caused the flip in the first place.
Now Alexandre Correira and Jacques Laskar suggest that Venus may not have flipped at all. They propose instead that its rotation slowed to a standstill and then reversed direction. Taking into account the factors mentioned above, as well as tidal effects from other planets, the team concluded that Venus's axis could have shifted to a variety of positions throughout the planet's evolution. Regardless of whether it flipped or not, it is bound to settle into one of four stable rotation states¿two in either direction. The researchers add that Venus would be more stable in one of the two retrograde rotational states. So in essence, it was just a question of time before Venus started spinning the wrong way.
See what we're tweeting about
7 Comments
Add CommentCould have Vesus's retrograde motion and that of some of Jupiter's moons been caused by a close encounter with another solar system?
Reply | Report Abuse | Link to thisThese findings don't seem to bode well for finding earth-like extra-solar planets. At the very least it would seem to narrow the range of possibilities. If Earth had not gained a large moon would the same thing have happened here? If Venus were a little smaller, with a thinner initial atmosphere, would it's rotation have slowed and reversed the same way?
Reply | Report Abuse | Link to thisIf this is the case, has there been any measurements on the rotational velocity of Venus, and whether it may be slowing down? If Venus's rotation IS slowing down, when will it change direction?
Reply | Report Abuse | Link to thisHere is the answer to this
Reply | Report Abuse | Link to thishttp://newtonugeam.com/PDFs/CHAPTER_7.pdf
Here is the true answer to it
Reply | Report Abuse | Link to thishttp://newtonugeam.com/PDFs/CHAPTER_7.pdf
As I look at the diagrams and movies of the convection cells in both the Sun's interior and the Earth's mantle and atmosphere, it can be noted that neighboring cells influence one another, causing neighbors to rotate in opposite directions. As the early solar system disk flattened out and eddies began to form in the regions which eventually became Mercury, Venus and Earth, might it be possible that the counter-clockwise flow of Mercury and Earth zone materials influenced the materials in the zone that became Venus, thus causing a clockwise flow? With the three inner planetary zones being relatively close together (compared to the distances between Earth and Mars as well as the Jovian planets), such an influence might indeed be possible.
Reply | Report Abuse | Link to thisIf Venus initially had a counter-clockwise rotation and was struck by another protoplanet of sufficient size and momentum to turn it upside down, I find it hard to believe that it would remain in a nearly circular orbit. It would be much more logical for it to settle out in a more elliptical orbit such as most likely occurred with Mercury due to an impact in its later stage of evolution. Also, relative to Mercury, its early zone of material that eventually caused it to form must have had more matter than Mercury now has, thus applying even more influence on the material in the zone of Venus if indeed it could have influenced an opposite rotational direction.
Reply | Report Abuse | Link to thisVenus has dense atmosphere, 90 times denser than of the Earth. Materialistic Sun-rays which spin the Venus bend towards the normal on entering into denser medium thus angle of their strike over the Venus’ surface changes. Angle of strike by the Sun-rays changes so much that Venus gets reverse spin direction. Reverse spin direction of the Venus is not by the reason as stated or by the hit of any big object as the World understands. Explanation over this fact/phenomenon by the dense atmosphere is under the relevant chapter under discovery claims.
Planet does not spin by the conservation of angular momentum but spins is by the materialistic rays of the Sun and the planet too. World has been challenged for wrong knowledge over the said subject. What is correct and how it works that all has been explained under the website www.newtonugeam.com.
Planet Uranus spins with its axis almost parallel to its orbital plane. Unique spin direction of the Uranus is also by the materialistic Sun-rays but because of unique shape of its solid cores which is deep inside the planet. Solid core of the Uranus is of prolate-shape because it has been formed by the clubbing of two past-era planets. Such shaped-core can not spin vertically over the equatorial plane of the Sun because of the reasons as explained under the said website.
Why Venus Spins the Wrong Way?
Without sketches, it is not possible to illustrate; hence to have the answer that why Venus spins the wrong way read chapter VENUS and also Missile Hit Astronomy Information and Torpedo Hit Astronomy Information over the website: www.newtonugeam.com.