1079 Our World





This is something I didn't know about our world:


In a single year, the Earth’s continents move a few centimetres. But over hundreds of millions of years, the entire surface of the Earth is recycled down into the red-hot mantle beneath the crust and new nutrient-rich land is created via volcanoes.


Without that renewal, the nutrients and minerals of the Earth’s surface would soon be depleted.


Louis Moresi, a professor of geodynamics at the Australian National University, said: “It’s like turning the soil over. The Earth is the only place we know it happens, and it’s the only place we know that there is life.”


This astonishes me ... think about it: Even if humans managed to not destroy themselves, or our planet, in the long run we would probably find it hard to adjust to major catastrophes, like earth quakes and volcano disruptions.


I like to speculate about the far, far future ... I have essays THE FUTURE  and Humanity's Potential, a synopsis of the book The Precipice: Existential Risks and the Future of Humanity, by Toby Ord.


But this article in the SMH is not about Earth, it is about Venus.




An artist’s impression of what the surface of Venus might look like.  AP / EUROPEAN SPACE AGENCYCREDIT:



Venus does not appear to have plate tectonics in the classic sense. But its surface is not old and weathered like that of the moon or Mars, and there are tantalising hints of mountains on the surface – signs of movement.


It is possible the surface is being rapidly weathered and turned over by the planet’s atmosphere, or another process we still don’t understand.


If it has its own form of plate tectonics, that will offer important clues for which planets circling other stars might be able to support life, said Professor Moresi.
































 

>