To date, hundreds of exoplanets have been discovered. GJ 581g, on the other hand, has the capacity to support life, which is what makes it so unique. Since the dawn of time, scientists have been trying to find planets the size of Earth and with the right temperature on their surface for liquid water to exist. However, the procedures used to detect these disorders have taken decades to improve.
The Gliese 581 system has been studied extensively by the geneva group using Harp’s facility. Over the last five or more years, the group had already detected four planets—two of which looked close to habitable. While one of them was on the hot side, just on the hot edge of the zone, the other was on the cold edge. Although they were close, the planets couldn’t withstand the advanced set of tests to be able to be called fit for living. Considering the Keplar’s data, the 4th planet, G, is a planet that could possibly sustain life.
What made scientists believe in life this time?
The project to discover planets started 25 years ago before any planets were known to humans. Over the last 15 years, finding Jupiter has been quite a success. The software analysis has been upgraded to improve precision in hopes to find Earth-like planets.
According to scientists, the planet has to be at the right distance from the stars so that it is neither too hot nor too cold. Besides, it must have roughly the proper surface gravity, that is, the gravitational force must be comparable to that of the earth so that it can hold onto a substantial atmosphere and allow the water to pool on the surface.
If a planet is too big about 15 Earth masses or is too small like Mars, it will not be able to hold onto an atmosphere. The ideal condition would be to have one earth mass or a few earth masses. The newly discovered planet is roughly the right size.
What does this discovery suggest for existence?
From the first principles of gravity, it is known that this planet is tidally locked with its star. It always keeps the same face pointing at the star just the same way as the moon keeps pointing towards the Earth. There is no day or night on this planet. The star remains in the same position no matter where we are on the planet.
It keeps one side facing the star, which is rather warm, and the other side towards perpetual night. The line between the light and dark, the terminator is where the sunrise can be observed. There are stable zones where the ecosystem stays at the same temperature and doesn’t change.
This suggests there is a great range of equal longitudes that will create a lot of different niches for a lot of different species to evolve stably. It has an environment that can promote life with sunlight. The similarities it bears of possesing a satellite planet. The most important survival element is water. And since this newly discovered planet can hold water, it can be a potential beginning of life and the hope of sustenance of life in outer space.