Thursday, 5 April 2012

Venus slowed rotation

Venus turning around its own axis in the last 16 years, slowed by as much as 6.5 minutes, according to a new European space probe measurements.

On the basis of data on the velocity of the surface neighboring planets, which were collected by 90 U.S. and Russian missions Magellan Venus, scientists have calculated that one Venus day is Earth's 243.015.

However, new measurements of Venus Express orbiter have surprised experts because they found that the same parts of the planet are less than 20 kilometers from where they should be according to previous measurements and calculations. In other words, Venus turns on its axis in 6.5 minutes slower than 16 years ago. Similar results are shown and radar measurements from Earth.

Venus Express follows the movements of Venus with powerful infrared detector, which penetrates through its dense atmosphere.

Dr. Are Smrekar, who works at NASA's Jet Propulsion Laboratory in Pasadena said the new results surprised naučćnike.

"At first we were skeptical," said planetary scientist and added:

"I thought that the resolution of 100 kilometers may not be sufficient as a word here about the difference of 20 kilometers. However, after I check the data, I am convinced that the results are accurate. This means that something is slowing the rotation of the planet, and we did not quite sure what it is. " 

The culprit is a thick atmosphere?

Scientists believe that it is possible that the causes of friction slowing down as it creates a dense atmosphere of Venus and fast winds. Studies have shown that similarly acting and movement of the Earth's atmosphere, however, to a lesser extent.

The atmosphere of Venus is composed mainly of CO2 and air pressure there is 90 times larger than Earth. In addition, thick clouds of sulfuric acid to its surface speed chase hurricanes.

But the research team Hakan Svedhem Venus Express says that, nevertheless, difficult to discover the mechanisms that cause such a big slowdown in only 16 years.

"It is possible that the cause of the solar cycle or weather conditions that shape the atmospheric dynamics. This puzzle is not solved," said Svedhem.

According to some experts, the cause of the unusual phenomenon could be the exchange of angular moments between Earth and Venus. For example, Moon can slow the rotation of the planet because they both share the angular momentum of the body.

But Svedhem believes that at a distance of at least 38 million kilometers should not be a moment of exchange between Venus and Earth and is believed to be the right answer only to determine the further research.


1 comment:

  1. The culprit is a thick atmosphere?

    You bet. Our solar system is under compression due to compaction of Sol's heliosphere by neutrino-heated Fluff, our local gas cloud. The neutrinos? Maybe G1.9 is antimatter and won't be around long. But while the compression is in effect, gases are thicker everywhere in the much reduced heliosphere. Nine months to go.