from the bananarama-has-nothing-on-this dept.
The European Space Agency ESA reports:
[On December 16th,] ESA’s Venus Express has ended its eight-year mission after far exceeding its planned life. The spacecraft exhausted its propellant during a series of thruster burns to raise its orbit following the low-altitude aerobraking earlier this year.
The amount of data collected will occupy scientists for at least another eight years:
Studies of the planet’s ‘super-rotating’ atmosphere – it whips around the planet in only four Earth-days, much faster than the 243 days the planet takes to complete one rotation about its axis – also turned up some intriguing surprises. When studying the winds, by tracking clouds in images, average wind speeds were found to have increased from roughly 300 km/h to 400 km/h over a period of six Earth years.
At the same time, a separate study found that the rotation of the planet had slowed by 6.5 minutes since NASA’s Magellan measured it before completing its five-year mission at Venus 20 years ago. However, it remains unknown if there is a direct relationship between the increasing wind speeds and the slowing rotation.
Other data strongly hints to current volcanic activity, whose existence is still disputed today.
(Score: 3, Funny) by bob_super on Wednesday December 17 2014, @10:27PM
>average wind speeds were found to have increased from roughly 300 km/h to 400 km/h
but also
Solar irradiance (W/m2) 2613.9 (Venus) 1367.6 (Earth) [Nasa [nasa.gov]]
Next time someone wants to shutdown a nuclear power plant near you, invite them to go live a life of all-renewable power on Venus...
(Score: 3, Informative) by Jeremiah Cornelius on Wednesday December 17 2014, @10:30PM
That GOOD night, you bodgers!
-- Dylan Thomas
You're betting on the pantomime horse...
(Score: 4, Interesting) by frojack on Wednesday December 17 2014, @10:44PM
When studying the winds, by tracking clouds in images, average wind speeds were found to have increased from roughly 300 km/h to 400 km/h over a period of six Earth years.
A 33% percent increase in cloud velocity in a mere 6 years!
What could possibly drive such an increase?
Is this a constant trend, or tied to solar output? Express arrived at Venus during a period where the sun's output was at a periodic low [wikipedia.org]. Perhaps we are seeing the result of periodic increased solar radiance.
The slowing of rotation was the topic of this Nat Geo article [nationalgeographic.com.au]. Short answer: Nobody knows why it is slowing so much.
No, you are mistaken. I've always had this sig.
(Score: 2) by VLM on Wednesday December 17 2014, @10:57PM
Perhaps we are seeing the result of periodic increased solar radiance.
Perhaps. Not agreeing or disagreeing. I would say that a bazillionth of a percent variation could be modeled by orbiting a really big moon around a planet. Assuming the effect would take hold in less than months because we're talking about only multiple years of data. Anyway there should be "some" effect where the average windspeed on the Earth would be microscopically lower during new moons that result in eclipses. Its not too far out of an idea. Maybe saturns rings block more light... sometimes, so Saturn might be a good model.
I suspect the bigger problem is drawing conclusions based on only a couple years of data. The solar cycle being 11 years, get about 33+ years of data and check back...
At least from a ham radio standpoint this is not exactly the most active solar cycle I've ever lived thru. So, it may have increased, but it hasn't much, since your graph.
(Score: 0) by Anonymous Coward on Wednesday December 17 2014, @11:11PM
Perhaps we are seeing the result of periodic increased solar radiance.
No.
That graph shows you that solar output is extremely stable. That variance is less than 0.1%.
0.1% does NOT result in anything significant happening anywhere.
(Score: 3, Informative) by frojack on Thursday December 18 2014, @12:00AM
The AC says:
That graph shows you that solar output is extremely stable. That variance is less than 0.1%.
0.1% does NOT result in anything significant happening anywhere.
NASA says: [nasa.gov]
Over the past century, Earth's average temperature has increased by approximately 0.6 degrees Celsius (1.1 degrees Fahrenheit). Solar heating accounts for about 0.15 C, or 25 percent, of this change, according to computer modeling results published by NASA Goddard Institute for Space Studies
Decisions decisions... AC, or NASA
Also, you provide no alternative suggestion for a 33% increase in atmospheric velocity. That takes a lot of energy. Where is it coming from?
No, you are mistaken. I've always had this sig.
(Score: 2) by c0lo on Thursday December 18 2014, @01:37AM
All the amazons on Venus started to paddle in the opposite direction (and both sulphuric acid and carbon dioxide are heavier than water). This accounts for both wind increase and the planet rotation slowdown.
The only unknown here is how many of them paddle.
https://www.youtube.com/watch?v=aoFiw2jMy-0
(Score: 2) by aristarchus on Thursday December 18 2014, @06:40AM
Highly inappropriate to be shilling for Big Oil in a thread about planetary science? Yes, "stuff about Venus" so it is alright to keep consuming petrochemicals! And, Nukes. Transparency is thy name, all praise the almighty astro-turf, which in this case is really turf about astro! Frojack, a bit more professionalism? Don't be so obvious, or you will lose what little credibility you have left.
(Score: 2) by frojack on Thursday December 18 2014, @08:17AM
Seriously, what the fuck are you talking about?
How did you get from the winds on Venus to big oil?
This is what I hate about anti corporate conspiracy nut jobs. Every story gets twisted to fit their paranoia.
No, you are mistaken. I've always had this sig.
(Score: 2) by aristarchus on Thursday December 18 2014, @08:49AM
C'mon, Frojack! Confess! We have a nice post about solar system exploration, and suddenly it is all about solar maximums, et cetera, which proves that anthropogenic global warming is not true! I like the fact that you did not make the connection, but just left it out there for anyone with half a brain, in fact it may have been specifically for those with half a brain. I would be much more interested in what Venus Express manages to tell us about the planet on it's death plunge, instead of an advertisement from British Petroleum, formerly known as the Anglo-Iranian Oil Company, what hired Kermit Roosevelt to overthrow the democratically elected government of some country that was not, notably, on Venus.
(Score: 2) by Buck Feta on Wednesday December 17 2014, @11:10PM
Apparently "Goes gently into the night" means crashing into a planet and being eaten by sulfuric acid. I'll stick with my plan of a heart attack at the end of a coke-fueled orgy with half a dozen strippers in a pool full of lime Jello.
- fractious political commentary goes here -
(Score: 0) by Anonymous Coward on Wednesday December 17 2014, @11:18PM
Do you do this much? Are there pictures?
(Score: 2) by richtopia on Thursday December 18 2014, @01:21AM
Rethink what you just claimed is the better option. While stripper option sounds gratifying, many people have previously done it. Now burning up on atmospheric entry, only a limited few even on earth, much less our sister planet.
(Score: 2) by wonkey_monkey on Thursday December 18 2014, @08:45AM
You pervert. Lime jello?
systemd is Roko's Basilisk
(Score: 2, Interesting) by Anonymous Coward on Wednesday December 17 2014, @11:35PM
a separate study found that the rotation of the planet had slowed by 6.5 minutes since NASA’s Magellan measured it before completing its five-year mission at Venus 20 years ago
Now THAT is very very interesting. Rotational inertia of a planet is tremendous. To slow down by 0.002% over 20 years is huge. If that was transferred to the atmosphere, it would fly off the planet. Something very weird must be happening there...
http://en.wikipedia.org/wiki/Tidal_acceleration#Quantitative_description_of_the_Earth.E2.80.93Moon_case [wikipedia.org]
For earth the effect is millliseconds per century, and we have a giant moon slowing us via tides. The effect on Venus is almost 5000x as much and it doesn't have any satellites, or an ocean to move around. What is going on over there? Tidal forces on Venus from the Sun are significantly lower than tidal fores on Earth from the moon (never mind the sun)
(Score: 2) by isostatic on Thursday December 18 2014, @01:11AM
My assumption is Magellan didn't measure it accurately. Yes, they say they've double checked the measurements,
http://www.mnn.com/earth-matters/space/stories/scientists-baffled-to-discover-that-venus-spin-is-slowing-down-0 [mnn.com]
"When the two maps did not align, I first thought there was a mistake in my calculations, as Magellan measured the value [of Venus's spin] very accurately," said planetary scientist Nils Müller. "But we have checked every possible error we could think of."
Read more: http://www.mnn.com/earth-matters/space/stories/scientists-baffled-to-discover-that-venus-spin-is-slowing-down-0#ixzz3MCviQKKv [mnn.com]
(Score: 0) by Anonymous Coward on Thursday December 18 2014, @02:40AM
Yes, which is more likely:
the planet slowing down or,
inaccurate initial data?
I'm sure there's a third option...
(Score: 2) by GreatAuntAnesthesia on Thursday December 18 2014, @09:17AM
> I'm sure there's a third option...
Treens.
(Score: 2) by geb on Thursday December 18 2014, @12:55PM
Earth's rotation changes occasionally following major earthquakes, if a large mass of rock or magma raises or lowers. Without exchanging any angular momentum outside the system, the planet can still spin faster or slower by changing internal mass distribution.
Venus is known to have an active core, but there's still a lot of doubt over how its plate tectonics work. It is possible that it has spectacular volcanic activity and earthquakes that might explain the change.