Earth was very much like Venus 4.5 billion years ago according to researchers

The team of scientists led by ETH researcher Paolo Sossi have completed an investigation that has implications for the possible origins of life on Earth. According to the researchers, insights into the atmosphere of the earth 4.5 billion years ago show that our planet would be hard to recognize compared to what we know today.

In the very distant past, the surface of the planet was covered entirely by magma. There is no debate that Earth's surface was covered in magma in the distant past, but it's not exactly clear what the atmosphere of Earth was like at the time. Sossi says that 4.5 billion years ago, magma was constantly exchanging gases with the overlying atmosphere. The air and the magma influenced each other, so you can learn about one by studying the other.

For their study, researchers created magma in the laboratory by mixing a powder that matches the composition of the Earth's molten mantle and heating it. Heating the material required using the latest technological advancements because the composition of the mantle-like powder was difficult to melt. Melting it required temperatures of around 2000 degrees Celsius, which required a special furnace. The furnace was heated by a laser, and inside the furnace could levitate magma, letting streams of hot gas mixtures flow around it.

Researchers believe the streams of gas mixtures were possible candidates for the primeval atmosphere 4.5 billion years ago as it was influenced by magma. Researchers specifically looked at how iron was oxidized within the magma. The level of iron oxidation in the cool-down magma allowed the scientists to compare to naturally occurring rocks that compose the Earth's mantle today called periodites.

After their material cooled from the magma state, the team found that the young earth had an atmosphere that was slightly oxidizing with carbon dioxide as its main constituent along with nitrogen and some water. The surface pressure was about 100 times what it is today, and the atmosphere was much higher due to the hot surface. Earth's atmosphere would've been similar to what we see on Venus today.