Venus' day gets even longer as its spin slows

Venus is spinning more slowly and astronomers don't know why.

www.bbc.co.uk...

Hi all,
I saw this on the beeb news (childrens site link for reason?) Very interesting???

Can anyone throw any light on it?

My oh my..is this accurate? I was not aware of this before.

In the 1990s, they worked out one Venusian day - the time for the planet to spin round once - lasted 243.018 Earth days.

But now, the European Space Agency's Venus Express orbiter shows Venus' spin is getting even slower and a day on Venus is now six and a half minutes longer.

From your source.

So can the rate at which it is slowing down be calculated to determine when it will...stop...if this trend continues? I wonder if there is uniformity in its rate of declining spin, if this is true. How very odd.

Thanks again for sharing this.

Another write up..........

news.nationalgeographic.com...

reply to post by CaptainBeno
I'll admit I can't throw much light on the slowing of Venus' rotation, but I did get a kick out of your thread title.

It put me very much in the mood of "Hello, paging Dr. Obvious" - no offense intended.

reply to post by Praetorius


Ha! yes just noticed that........duh!!

Has anyone ever considered what would happen if all the planets suddenly reverse their orbits?





Fascinating concept to ponder

reply to post by truthinfact


I'm thinking I might buy some chain

As it spins in an opposite direction to the rest of us, do you think it would eventually slow down enough to start spinning the same as us? Just a thought?

Venus is the only planet which rotates retrograde meaning if the is more 'drag' on the outside, it will slow, stop and reverse, but it could be millions of years. Laws of physics.

Wellll, I'm thinking the rotational force in a vacuum should continue on and on forever... like clockwork.... But, I would suggest Venuses heavy atmosphere creates a form of drag/friction..?? (like you feel trying to spin underwater for example) Mind you, Earths day is not perfectly stagnant either, so I'd hardly say scientists are baffled.

reply to post by oghamxx


Have you ever wondered why that is the case ?

Laws of physics ? But what laws ?

Try using electrically charged bodys. (Polarity)



It's not 21 .... Its 2 in 1

End of comments

Actually the data taken as a whole and at face value simply indicate a non-constant rotation rate for Venus. Multiple earth-based radar studies measured the rotation rate of Venus prior to Magellan and arrived at numbers between 243.022~243.025 plus or minus 0.002~0.006. They used a couple of techniques to try to measure the rotation rate using Magellan (an earlier probe with which the accepted value was established prior to Venus Express), but the method they ultimately went with involved improving the spacecraft ephemeris to attain the accuracy needed to measure the rotation. This resulted in an order of magnitude improvement in the uncertainty level of the measurements as compared to other techniques and produced the current accepted number of 243.0185 plus or minus 0.0001. Venus Express, on the other hand, now finds the value to be 243.023 days.

Interestingly though, when they tried to establish a longer baseline of measurement using older data from the Soviet Venera 15/16 probes, the resulting rotational period solution was 243.023 plus or minus 0.001 days (look familiar?). This joint Venera-Magellan solution was disregarded though as being subject to ephemeris errors in the Venera probes that could not be corrected the way they were for Magellan, as well as the fact that Venera did not have as much radar resolution as Magellan. In light of the current evidence it seems it may have not been an incorrect solution, in fact it matches Venus Express' solution.

At best the new Venus Express data means that Venus' rotation is variable due to atmospheric and possibly geological forces at work under the surface as well, but taken as a whole the data do not indicate a steady slowing, rather they indicate an inconstant rate of rotation. At worst it simply indicates that the method previously employed method to improve the ephemeris of Magellan was wrong or otherwise flawed, and that the true value always was 243.023 days. In any case, I personally doubt that it's just a coincidence that the Venera-Magellan combined solution matches the Venus Express solution.


M. E. DAVIES,T. R. COLVIN,P. G. ROGERS, P. W. CHODAS, W. L. SJOGREN, E. L. AKIM, V. A. STEPANYANTZ, Z. P. VLASOVA, A. I. ZAKHAROV. 1992. The Rotation Period, Direction of the North Pole, and Geodetic Control Network of Venus. Journal of Geophysical Research. Vol 97, No. E8, Pg 13, 141-13, 151.

Taken from the zetatalk website:

Where Venus is not a magnetic planet, it none the less is not homogeneous throughout, so has points of attraction that can be grabbed and held back during rotation. It also has clumps of matter than become involved in a repulsion dance with any passing object. Venus is caught in the cup, and is thus quite close to the passing Planet X. It is absolutely subject to such push/pull maneuvers, as is the Earth. In 2003, when Planet X zoomed into the inner solar system, the Earth experienced slowing which totaled 37 minutes. This was hidden from the public, due to the cover-up, by periodic adjustments by the Navy, the master clock keeper. When Planet X moved closer to the Sun, this slowing stopped as the Sun was now again the uncontested dictator controlling the Earth's rotation.

Why would the scientific community publish such a minor detail as a slowing rotation in Venus, openly, when this is likely to raise yet more questions about what might be in the inner solar system? This is in anticipation of slowing rotation in the Earth returning, to throw confusion over the source of this. The cover-up is alive and well! Blame the Sun can be expected, as Venus is closer to the Sun than the Earth, and the claim will be that Venus experienced this slowing first. Of course, the slowing they anticipate to occur on Earth is much greater than 6 minutes. It is expected that even with the Navy's manipulations, the common man will notice the slowing on their manual clocks.

Originally posted by Haites
Taken from the zetatalk website:

Sorry, but there really isn't anything of any redeeming value in that website. Measurements made prior to the Magellan probe (and when using Venera-Magellan together) shows the rotation of Venus to be precisely as slow as was measured by Venus Express. Trying to blame it on a magical planet that somehow has stopped our orbital motion (yet the stars and planets are actually all right where they should be in the sky) is just silly.