Plate tectonics could be the source of all life on Earth (and on alien planets too)

Plate tectonic activity has been blamed for major earthquakes and tsunamis since the idea, first put forward in 1912 by meteorologist Alfred Wegener, has existed.

Subduction forces obliterated entire continents during the 3.2 billion years that plate tectonics occurred on our 4.5 billion year old Earth. The planet’s crust is sunk into the inner layers of Earth’s warm mantle, where annihilation awaits.

An illustration of the generally accepted theory of plate tectonics. New research claims that this activity led to the development of life on Earth. (stock photography)

New research argues that the source of so much destruction is also the source of life. You see, behind these apocalyptic events, there is something critical to life as we know it: researcher Rajagopal Anand argues that early Earth’s orbital patterns may have been key to making plate tectonics possible.

If we are to find habitable worlds – think of them as new Earths – we may need to consider the larger picture of cosmic planetary motion.

The idea is put forward in Anand’s research paper which has not been peer reviewed and was published this week on arXiv, a hub for “pre-print” studies that have not been published. in an academic journal.

Plate tectonics could be crucial for the formation of life on alien worlds

The tectonics of Earth’s plates depend on mass, internal viscosity contrast, availability of liquid water, and heat from the planet’s core. But the initial spin rate, in addition to our planet’s revolutionary periodicity as it moves around the sun, is crucial for plate tectonic activity to begin, Anand says.

“Earth’s initial orbital conditions were significantly influenced by the diametral processes of core segregation and moon formation, and this likely led to the possibility of the initiation and persistence of plate tectonics” , proposes the article.

With a contrast in viscosity between the planet’s layers, an intense heat source, and the availability of liquid water, the up and down motion of the mantle (called mantle convection) interacts to give motion to the plates of the rocky crust. of a planet. But for this motion to continue, the rocky body must spin on its axis and orbit its star in a specific way to reach habitable conditions.

Here on Earth, its unique orbital conditions were dramatically altered, millions of years after the formation of the solar system, when the moon appeared following a cataclysmic impact with another small planet.

Adding a term to the equation for life in the universe

This impact is believed to have accelerated the rotational speed of the Earth from its original rotational speed. And, this – in conjunction with the moon’s separation process, which is still occurring (for example, tidal forces gradually slowing Earth’s rotation) – has “far-reaching implications for the initiation of tectonics plates and the emergence of life,” writes Anand.

Plate tectonics provides essential initiators for life – a changing crust of the planet is one – and for the development of the hydrosphere and an atmosphere.

The changing shape of the crust also provides new sources and sinks for sedimentary processes that circulate nutrients for the evolution and diversity of organic life.

Researchers have found that optimal conditions of rotational and revolving periodicities are essential for the development of plate tectonics.

At least they could have been on Earth. And if so, it could help solve one of the necessary conditions for habitable conditions on alien worlds beyond our solar system.

Europa, Mars and Venus do not have the parameters of life as we know it

Europa is closely linked to its host planet, Jupiter. This relationship prevented the development of plate tectonics since the gravitational strain on the Jovian moon is uneven. In other words, it could be that Europa, despite its deep oceans, is missing one of the crucial characteristics for the evolution of organic life. At least, life as we know it.

Both Mars and Venus have all the ingredients to form long-lived radioactive isotopes, which create an additional heat source and thus mantle convection. Yet both planets are tectonically “dead with a stagnant lid,” according to the study. Things might have turned out differently for our closest planetary cousins ​​had orbital and spin velocities approached the equivalence ratio of rotational periodicity. It almost corresponds to the time it takes for the planet to move one degree in its orbit around the sun.

Earth's tectonic plates
Earth’s tectonic plates.

Expand the Parameters of Interstellar Life — Earth’s current periodicity of 365 days stacked against its rotational periodicity of 0.997 days has contributed to optimal conditions for plate tectonics. If we’re going to find another planet beyond our solar system like ours, we might have better luck looking for a match in the orbital parameters.

Other parameters, such as the distance from the Earth to the sun in relation to the size of the latter, in addition to the distance from our planet to huge gas giants, such as Jupiter, are crucial for life.

Humans must continue to work out the unknown terms of the equation that determines how, when and where life can arise on extraterrestrial worlds, if we are ever to learn, for sure, whether or not we are alone in the universe. .

Summary of the study:

The existence of plate tectonics on Earth is directly dependent on the internal viscosity contrast, the mass of the planet, the availability of liquid water, and an internal heat source. However, the initial conditions of rotational speed and revolutionary periodicity of the Earth around the Sun must also have been important for the onset of plate tectonics. Earth’s initial orbital conditions were significantly influenced by the diametral processes of core segregation and Moon formation, which likely led to the possibility of the initiation and persistence of plate tectonics. The change in orbital conditions could have caused Earth to evolve in a near-linear trend so that the planet’s rotational periodicity (TP) could approach the time taken for the planet to travel one degree in its orbit around the Sun (T1degree ) , i.e. TP ~ T1 degree. Such an optimal condition for the periodicities of rotation and revolution could be essential for the development of plate tectonics on Earth. This hypothesis has direct implications for the possibility of plate tectonics and life in extrasolar planets and potentially habitable solar planetary bodies such as Europa and Mars.

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