Venus May Have Active Volcanoes

An anonymous reader writes: The European Space Agency's Venus Express spacecraft has discovered hot lava flows on the surface of Venus, providing the best evidence yet that the planet may have active volcanoes. "[U]sing a near-infrared channel of the spacecraft's Venus Monitoring Camera (VMC) to map thermal emission from the surface through a transparent spectral window in the planet's atmosphere, an international team of planetary scientists has spotted localized changes in surface brightness between images taken only a few days apart (abstract)." Venus is fairly similar to Earth in size and composition, which suggests it has an internal heat source. One of the biggest mysteries about Venus is how that heat escapes, and volcanic activity could be the answer.

Comments

Lack of Magnetic Field

[currently_awake]

It is generally believed that the earths magnetic field protects the atmosphere from being stripped away by the solar wind. Given that Venus has no (very small) magnetic field, this explains why the planet has such a dense atmosphere. Can anyone explain why a volcanicly active planet doesn't have a magnetic field? Isn't the liquid core what generates the field?

Re:Lack of Magnetic Field

[phantomfive]

Can anyone explain why a volcanicly active planet doesn't have a magnetic field? Isn't the liquid core what generates the field?

Probably because it has a very slow rotation.

Re:Lack of Magnetic Field

[turkeydance]

+1. Venus rotates slower than i walk.

Re:Lack of Magnetic Field

[Guy From V]

It looks like Venus might have a frozen core as far as we know, at least from a few minutes of Googling and finding a couple hits mentioning that. -> http://cseligman.com/text/plan...

Re:Lack of Magnetic Field

[phantomfive]

Wikipedia has a really good article about the geology of Venus. Worth a read.

Re:Lack of Magnetic Field

[Bite The Pillow]

It is generally believed

by whom? Citation needed.

Can anyone explain

Relative to the limits of your understanding, yes. Otherwise, I suppose you should ask the European Space Agency, because it would seem that they are, as of now, the experts in such questions.

Re:Lack of Magnetic Field

[linearZ]

Venus is rotating in an oddball direction - against its orbit and accompanying tidal forces. The common explanation is that Venus got hit by something big enough to change its rotation, and may have even been what caused the atmosphere to be hosed.

Re:Lack of Magnetic Field

[paradigmsareconstruc]

Venus is the most important archetype in mythology. The stories tend to share a common theme of Venus going through a dramatic transition from an object of beauty to one of horror.

What people have generally failed to realize is that Plato believed in a recent, human-historical event in the solar system, and he attributed all of the mythological archetypes to this single event.

From Plato's Dialogues at https://books.google.com/books...

"Phaethon, the son of Helios, having yoked the steeds in his father's chariot, because he was not able to drive them in the path of his father, burned up all that was upon the earth, and was himself destroyed by a thunderbolt. Now, this has the form of a myth, but really signifies a declination of the bodies moving around the earth and in the heavens, and a great conflagration of things upon the earth recurring at long intervals of time"

(Notice that Plato is unwittingly describing a debris field that would regularly return to the earth after an initial catastrophe -- even though Plato has no idea what gravity or a debris field actually is ...)

And, to make sure that everybody understands the meaning of the ancient myths, he further states:

"All of these stories, and ten thousand others which are still more wonderful, have a common origin*; many of them have been lost in the lapse of ages, or exist only as fragments; *but the origin of them is what no one has told"

We can debate his intent, but what I generally find is that people are not actually aware that Plato said this at all.

Re:Lack of Magnetic Field

[AK Marc]

The oddball rotation is the same as everyone else, just so slow that when you account for it revolving around the sun, it's sunrise and sunset are the opposite of everyone else's.

The lack of magnetic field is what makes the atmosphere dense. O2 is lighter than the other compounds in the atmosphere, so it floats to the top, where the solar wind strips the upper layers of the atmosphere. So if we were able to terraform the planet, changing the atmosphere to breathable, it wouldn't be a stable transformation, and the atmosphere would return to something like it has now. All from the lack of a magentic field.

Re:Lack of Magnetic Field

[Pete Venkman]

You should be a guest on Coast to Coast AM!

Re:Lack of Magnetic Field

[someone1234]

Wait a minute. Mars' thin atmosphere is also explained by the small magnetic field. How could a magnetic field be held responsible for both?
Especially, when you say the atmosphere would be stripped away by the solar wind. How dense it would be without being stripped away?

Re:Lack of Magnetic Field

[CrimsonAvenger]

It is generally believed that the earths magnetic field protects the atmosphere from being stripped away by the solar wind. Given that Venus has no (very small) magnetic field, this explains why the planet has such a dense atmosphere.

So, our magnetic field gives Earth a thick atmosphere, but Venus' lack of a magnetic field gives it an even thicker atmosphere?

I'm missing something obviously....

Re:Lack of Magnetic Field

[inasity_rules]

Venus is the most important archetype in mythology. The stories tend to share a common theme of Venus going through a dramatic transition from an object of beauty to one of horror.

Well, that is not a subjective statement at all.

No Plate Tectonics

[Guy From V]

Since there's no evidence of any plate tectonics whatsoever like Earth, that heat from tidal forces etc. that builds and dissipates any normal magnetic field...? I'm guessing here.

Re:No Plate Tectonics

[phantomfive]

Plate tectonics might not be present on Venus because of "self repair."

Re:No Plate Tectonics

[RockDoctor]

Since there's no evidence of any plate tectonics whatsoever like Earth,

Venus doesn't seem to have the same tectonic style as Earth. At the moment. Beyond that ... I'm not going to speculate geologically. (Or even Veneraly. Or Venialy.) One thing that we don't know is how many different styles of planetary tectonics are possible (or if the number is significantly lower than the number of planets).

that heat from tidal forces etc. that builds and dissipates any normal magnetic field...?

Doesn't work : the magnetic field of Earth is generated in the core at temperatures several thousand kelvin above the temperature at which the permanent magnets which you seem to be thinking of cease to work. The Earth's magnetic field is thought to be the result of a self-exciting dynamo - which doesn't have an upper temperature limit, they operate just as well in plasmas in the many thousands of Kelvin, and in fresh neutron stars at approaching a GK (giga-Kelvin ; no, I'm not joking.).

I'm guessing here.

But you're admitting it, which is bizarre and unusual behaviour for Slashdot, and suggests that you might actually learn something.

Flows

[Rei]

They mentioned that the flow temperatures recorded in the hot pixels are colder than typical basaltic / rhyolitic flows and were speculating that they didn't catch freshly erupting material, but rather material that had a little time to cool. But I can't help but wonder.... does Venus have carbonatite flows? They're colder, and if there's anything Venus isn't short on, it's carbonic compounds...

(BTW, with those not familiar with carbonatite lava, its really weird stuff - incredibly fast-flowing and smooth (often less viscous than water), erupts looking black or dark gray like oil, doesn't (visibly) glow during the day (just a fast moving black substance), at night it has a weird maroon glow, and it oxidizes to bright white as it ages)

(Just one of many unusual types of volcano :) )

Re:Flows

[Rei]

You know, I should really learn to google things before I suggest "new" ideas ;)

Re:Flows

[Twinbee]

Here's a video of aforementioned lava: https://www.youtube.com/watch?...

Looks dangerous. At least with normal lava, you can walk on it if you're quick enough.

Re:The sad destruction of Slashdot

[turkeydance]

well, i agree. the target demographic ain't us.

This proves my theory! Venus has acid clouds...

[Gravis Zero]

and some asteroids are made if baking soda!

Re:The sad destruction of Slashdot

[daniel23]

I'm dismayed at how much Dice cares so little for its legacy audience. It's long time readers and the community here that allows no BS to go unchecked. Beta was so big and fucking ugly it was easy for those with soul to largely rebel and reject it. Where's Beta now? They pretty much gave up. But now with the hideous changing of comment counts and remove of the original "read more" link layout, the sign has been posted. Dice and its soulless corporate minions intend to slowly take shots here and there, little by little. Slowly they will destroy this venerable, classic old home to many on the web. And it's just a GOD DAMN SHAME.

removing the well mknown "read more" link from the bottom of the news item and instead creating a grotesquely large #-of-comments counter next to the heading is counter-intuitive and bad interface design.

I read the heading, if it anyhow interests me I read the summary and if I still feel interested I go for the "read more". This is top-down and the old design ws in harmony with it. Now I'm forced to go back again and click the link on the opposite end of the entry. This design interrupts the "natural flow" of eyeball and mouse-pointer movements and actually results in dimished clicks.

I guess some marketing droids decided to try and give /. more of an 2.0 appearance in the hope of attracting new (younger, more consume-oriented) readers and raise income froms ads. But destroying the usability of the site does not attract new users, it alienates the current users instead. If dice want to bring slashdot to the presence they should add features this site has ignored for much to long:
utf-8
https:///
ipv6

Too geekish? Think again! FB does all of those and look how many clicks they net in...

Obligatory: Oh, my!

[__aaclcg7560]

So Venus has hot flashes?

Lack of moons = no vulcanism?

[bradley13]

Maybe I'm out of date here, but I thought there was general agreement that moonless planets would just quietly cool from the outside in. No plate tectonics or vulcanism, because there are no tides to stir things up.

Since TFA writes "These observations are close to the limits of the spacecraft’s capabilities and it was extremely difficult to make these detections", maybe this should be taken with a large grain of salt?

Re:Lack of moons = no vulcanism?

[daniel23]

Venus having active volcanos would be hot though.

Fixed that for you