Venus is the least understood of the terrestrial planets. Despite broad similarities to the Earth in mass and size, Venus has no evidence of plate tectonics recorded on its young surface, and Venus’ atmosphere is strikingly different. New research from Brown University offers evidence that Venus had plate tectonics billions of years ago.
Plate tectonics is a process critical to life that involves multiple continental plates pushing, pulling and sliding beneath one another.
On Earth, this process intensified over billions of years, forming new continents and mountains, and leading to chemical reactions that stabilized the planet’s surface temperature, resulting in an environment more conducive to the development of life.
Venus, on the other hand, Earth’s nearest neighbor and sister planet, went in the opposite direction and today has surface temperatures hot enough to melt lead.
One explanation is that the planet has always been thought to have what’s known as a stagnant lid, meaning its surface has only a single plate with minimal amounts of give, movement and gasses being released into the atmosphere.
A new paper published in the journal Nature Astronomy posits that this wasn’t always the case.
To account for the abundance of nitrogen and carbon dioxide present in Venus’ atmosphere, the authors conclude that Venus must have had plate tectonics sometime after the planet formed, about 4.5 billion to 3.5 billion years ago.
They suggest that this early tectonic movement, like on Earth, would have been limited in terms of the number of plates moving and in how much they shifted. It also would have been happening on Earth and Venus simultaneously.
“One of the big picture takeaways is that we very likely had two planets at the same time in the same Solar System operating in a plate tectonic regime — the same mode of tectonics that allowed for the life that we see on Earth today,” said Dr. Matt Weller, who completed the work while he was a…
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