New Form of Planetary Tectonics Probably Present on Venus

[Area54]

I've placed this in Earth Science, rather than Astronomy, because it is, in essence, a geological tale.

And I've put it in Earth Science, rather than Science News,  because I'd like to see this sub-forum get more traffic.

Three interesting papers have been presented at the 49th Lunar & Planetary Science Conference in The Woodlands, Texas that address tectonics on Venus.

• The lithosphere of Venus has been broken and, in places, mobile
• Venus crustal tectonics analagous to jostling pack ice
• Life potential on early Venus connected to climate and geological history

The majority of planetary scientists consider Venus to lack plate tectonic activity. Though some researchers have occassionally pointed out features that could be evidence for plate tectonics, these notions have generally been dismissed and Venus has been viewed as having a stagnant lid -  a single, fixed lithospheric plate, rather than the multiple mobile plates found on Earth. This lid is thought to have overturned in the last billion years as a mechanism for heat loss, a heat loss otherwise restricted in the absence of plate tectonics.

The first two papers discuss an alternative, presenting the evidence for thin crustal plates that engage in small, irregular movements at their contact areas. This is not the large scale movement, with subduction, generation of new crust and creation of transform faults, in which plates can be transported across the planet, broken up and welded onto other plates, but a comparatively minor "rubbing together". Nevertheless this can modify the topography and facilitate heat loss.

The third paper considers the impact of Venus's tectonic regimes for supporting viable conditions for life (as we know it).

This article from Science News contains a digestible discussion for those who do not wish to read the papers themselves. Understanding the range and character of planetary tectonics will be essential (though obviously not sufficient) in properly estimating the probabilties for life on exoplanets.

[billiards]

On 3/26/2018 at 5:40 AM, Area54 said:

 

The majority of planetary scientists consider Venus to lack plate tectonic activity. Though some researchers have occassionally pointed out features that could be evidence for plate tectonics, these notions have generally been dismissed and Venus has been viewed as having a stagnant lid -  a single, fixed lithospheric plate, rather than the multiple mobile plates found on Earth. This lid is thought to have overturned in the last billion years as a mechanism for heat loss, a heat loss otherwise restricted in the absence of plate tectonics.

 

What do you mean when you say the lid has overturned?  Would this not require some kind of breakup and plate movement?  I.e. would this not count as "plate tectonics"?