Scientists at Washington University in St. Louis have been playing the role of super-villains lately. The scientist were not content just talking about vaporizing the Earth to understand “what to look for in the atmospheres of candidate super-Earths.” They had ultimately initiated the process to vaporize the Earth slowly. Don’t be scared! All of it was done in a simulator.
The chief reason for carrying out this experiment was curiosity. The researchers wanted to know what it would be like if our Earth reached such high temperatures that it would evaporate. In the words of Bruce Fegle, a professor of earth and planetary sciences, “We want to understand exactly what it would be like if it happened.”
Another purpose of this experiment was to simulate the environment of an ultra-hot super-Earth, so that when astronomers come across such planetary objects, they would have a good idea of what to expect.
The super-Earths are normally quite close to stars, which raises their average temperatures so high that they reach rock-melting points. The researchers wanted to know exactly what happens when the rocks melt.
To carry out the experiment, they ‘evaporated’ two types of pseudo-Earth. One of these was like our very own Earth, with a continental crust. This crust melted off at 940°C. A second pseudo-Earth, which was a bulk silicate mass, was also tested. This bulk silicate Earth vaporised at 1730°C.
The composition of the atmosphere also changed with the changing temperatures. For instance, below 730°C, the atmosphere contained ammonia and methane. Once the temperature reached 1430°C, the atmosphere would become fraught with silicon monoxide on both planets. Eventually, the silicon monoxide and melted rocks may condense and pebble down as iron.
Fegley concludes by saying, “You’re left with a big ball of steaming gas that’s knocking you on the head with pebbles and droplets of liquid iron” once you are done with vaporizing the Earth completely.
Source: Washington University