And so it is quite special that life did not arise on Venus, but on our planet.
Four and a half billion years ago, the Earth would have been difficult to recognize. Instead of forests, mountains and oceans, our planet’s surface was completely covered with scalding hot magma. So much for the scientific consensus. Because what is less clear is what the atmosphere of our planet looked like at the time. And a new research team has become deeply rooted in that persistent topic.
Primal atmosphere of the earth
In a new study scientists have attempted to solve some of the mysteries about Earth’s primordial atmosphere. “4.5 billion years ago, the magma and overlying atmosphere were constantly exchanging gases,” explains study leader Paolo Sossi. “The sky and the magma influenced each other. So you can learn through one from the other. ”
Own magma
To learn more about Earth’s primordial atmosphere, the researchers decided to mimic the magma in the lab. How? By mixing a powder that matches the composition of the molten mantle and then heating it. While this may sound simple, it requires the latest technological advancements. “The composition of our shell-like powder made the mixture difficult to melt,” notes Sossi. “We needed very high temperatures of no less than 2000 degrees Celsius.” The researchers used a special oven that was heated with a laser. The researchers then let gas mixtures flow past it, which behaved like a real mini-atmosphere. These gas mixtures were plausible candidates for the primordial atmosphere that influenced the magma just like 4.5 billion years ago.
This close-up of the experiment shows the hot magma sample surrounded by gas. Image: P. Sossi / ETH Zurich
–
The researchers discovered that different gas mixtures had a different effect on the magma. “We mainly looked to what extent the iron in the magma oxidized,” explains Sossi. In simpler terms; how rusty the iron in the magma got. When iron reacts with oxygen in the presence of water, it creates rust. This process is also called oxidation. And that provided the researchers with important information.
Peridotites
The researchers then compared their samples to a naturally occurring rock called peridotites. These rocks today form the Earth’s mantle and still harbor traces of the Earth’s primordial atmosphere. By comparing the natural peridotites and those from the laboratory, the scientists got an idea which of their gas mixtures most closely resembled those of Earth’s original atmosphere.
Discovery
The researchers come to an interesting discovery. “We found that the young Earth, after it cooled, harbored an atmosphere that oxidized light,” says Sossi. “This atmosphere was mostly carbon dioxide, as well as some nitrogen and water.” The surface pressure was a lot higher; almost a hundred times as high as now. The atmosphere was also much higher due to the hot surface. And perhaps these characteristics are now familiar to you. For it means that the atmosphere of the young Earth was surprisingly similar to that of modern-day Venus.
Similar atmospheres
It’s an interesting finding. Because the research shows that Earth and Venus once harbored similar atmospheres. And that while Venus today is anything but a hospitable planet, while on Earth there is plenty of life to be found. So the Earth’s atmosphere has changed drastically over time. Why Venus retained its hellishly hot and poisonous atmosphere and Earth not? The answer is that Venus is too close to the sun. Due to the high temperatures, Venus lost all water. However, the earth retained the water, mainly in the form of oceans. These then absorbed a lot of CO2 from the air, which significantly reduced CO2 concentrations.
In this way, conditions on Earth eventually became favorable for life to emerge. Something that was not forthcoming on Venus. Still, it may well be that conditions on Venus have not always been so harsh and angry. In fact, some researchers argue that our closest neighbor is in the distant past had a stable climate and was livable. Moreover, it could well be that Venus would still have been livable today, were it not that planet Jupiter has put a stop to that …
–
Keep amazed ✨
Receive the most beautiful space photos and interesting popular science articles every Friday. Get the free Scientias Magazine together with 50,000 others.
