Scientists at Rutgers University in the United States have found places where alien life could have existed on Mars when there was still liquid water on it. At that time, the Sun was colder and less bright, so the planet’s surface was probably not suitable for living organisms.
According to researchers, even if Mars had a dense atmosphere with a high content of carbon dioxide and water vapor, the climate was not wet and warm enough. However, life could exist underground, supported by the warmth of geothermal sources. This solves the paradox of a weak young Sun, according to which the presence of liquid water in the early solar system about four billion years ago contradicts the fact that sunlight was 30 percent dimmer.
Climatic models predict that 3.7-4.1 billion years ago the surface temperature on Mars barely reached -0.15 degrees Celsius. However, the researchers determined that there was enough heat in the depths of the planet to make the ground water exist in liquid form. Meteorite strikes provided additional heat. According to the conclusions of scientists, it is groundwater can serve as a suitable habitat for living organisms and still exist somewhere under the surface.