Saturday, October 16, 2021 10:10 AM (GMT+7)
Previous studies suggested that Venus was once covered by oceans, but a new study has found the opposite.
Venus – twin planet with Earth
Venus, our nearest neighbor, is known as the “twin sister” to Earth because of the similarity in size and density of both planets.
While Earth is a natural center for life, Venus is a lifeless planet with a toxic carbon dioxide atmosphere 90 times thicker than ours, clouds of sulfuric acid, and surface temperatures. up to 864 degrees F (462 degrees C) – hot enough to melt lead.
To understand how these two planets came to be so different, a team of astrophysicists decided to try to simulate the beginning, when the planets in our solar system formed. 4.5 billion years ago.
They used climate models – similar to what researchers use when simulating climate change on Earth – to look back in time at Venus and the young Earth.
This new study has been published in the journal Nature.
When Earth and Venus were smelters
More than 4 billion years ago, Earth and Venus were both hot and covered with magma.
Oceans can only form when temperatures are cool enough for water to condense and fall as rain over thousands of years. That’s how Earth’s global ocean formed over tens of millions of years. On the other hand, Venus is still hot.
At that time, our sun was about 25% dimmer than it is now. But that won’t be enough to help Venus cool, since it’s the second-closest planet to the sun.
This climate model determined that clouds did contribute, but in an unexpected way. They gather on the night side of Venus, where they won’t be able to shield the day side of the planet from the sun.
Instead of shielding Venus from the heat, night-side clouds contribute to the greenhouse effect, trapping heat in the dense atmosphere and keeping temperatures high. With such steady heat trapped, Venus is too hot to rain. Instead, water can only exist as a gas, water vapor, in the atmosphere.
Why does the Earth have life?
Things could go the same way for Earth if our planet were a little closer to the sun or if the sun was as bright as it is now.
Because the sun dimmed billions of years ago, the Earth was able to cool down enough from its molten state for water to form and create our global ocean. “The weak young sun” was the key ingredient to actually forming the first oceans on Earth, Turbet wrote in an email.
“This is a complete reversal in how we look at what has long been called the ‘fading young Sun paradox,'” said Emeline Bolmont, study co-author and professor at the University of Geneva. ‘”.
Previously, scientists believed that if solar radiation were weaker than billions of years ago, the Earth would turn into a snowball.
Earth’s oceans have existed for nearly 4 billion years. There is evidence that Mars was covered with rivers and lakes between 3.5 billion and 3.8 billion years ago. And now it seems unlikely that Venus could support liquid water on its surface.
The NASA and European Space Agency missions, to be launched later this decade, will help scientists understand the oldest surface features on Venus that could hold pieces of evidence about past traces of the presence (or absence) of the liquid.
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