Science Time Machine | What is the relationship between the "super-Earth" discovered ten years ago and the Earth?

March 11, 2015 British astronomers discovered a "super-Earth"

On March 11, 2015, British astronomers made a breakthrough discovery - confirming the existence of a "super-Earth". This major achievement was subsequently officially reported for the first time by the British authoritative scientific journal Nature. The planet was named "Gliese 581d" and is located in the distant universe 22 light years away from Earth.

Gliese 581d is the only planet with habitable conditions discovered outside the solar system. This discovery not only broadens the boundaries of human cognition of the universe, but also provides new hope and direction for the future exploration of extraterrestrial life.

Necessary conditions for the origin of life

Gliese 581d is about three times the size of Earth and is the first Earth-like planet discovered outside the solar system that is located in the habitable zone of a star. It is known as a "super-Earth". The planet is 22 light-years away from Earth and can be regarded as a close neighbor on a cosmic scale.

Astronomers named Gliese 581d a super-Earth because its external environment is highly similar to that of the Earth and it possesses the key elements for the origin of life: basic molecules, liquid water, a stable energy source and suitable climatic conditions.

In 2014, scientists once misjudged the planet as "data noise" caused by star spots when observing it. Subsequently, scientists from Queen Mary University of London and the University of Hertford questioned the research method in 2014 and confirmed the existence of "581d" through new research. Because it is located in the habitable zone of its parent star, the planet was officially named "581d".

In fact, Gliese 581d is eight times more massive than Earth and was formed 10 billion years ago when the universe was expanding. If advanced civilizations really exist, this planet may be their origin. However, even with the fastest aircraft currently available to humans, it would take 80,000 years to reach this planet.

The birth of life on Earth

In the vast universe, the earth is just an ordinary celestial body in the solar system, and the solar system is just a tiny part of the universe, without any shining points.

Scientists are certain that there are billions of celestial bodies in the universe that are similar to Earth. However, scientists still cannot give a clear answer to the question of whether there is life outside Earth.

From the perspective of the evolution of the earth's environment, about 2.6 billion years ago, the earth's atmospheric environment underwent a major change. The ozone layer was formed at this time, effectively blocking external ultraviolet rays and promoting the diffusion of oxygen in the atmosphere.

Initially, oxygen was not essential for life, and ancient life did not rely on oxygen to survive. It was not until about 1.8 billion years ago that some bacteria mastered the ability to breathe aerobically, opening up a new model for the development of life. Aerobic respiration provides the necessary energy for life activities, promotes compatibility between cells, and promotes the natural evolution of life.

The Cambrian period about 530 million years ago marked an important node in the history of life, when species exploded. Since then, life on Earth has gradually been dominated by animals. It is amazing that the primitive forms of modern animals appeared in a very short period of time. Even the subsequent mass extinction events failed to erase the traces of this evolution of life until the rise of human civilization.

After in-depth research on the origin of life on Earth, many astronomers have devoted themselves to searching for celestial bodies similar to Earth in the hope of discovering traces of extraterrestrial life. Unfortunately, no conclusive conclusion has been reached so far. The conditions for the birth of life on Earth are extremely special. Rather than being harsh, it is better to regard it as a rare coincidence. Scientists have concluded that the perfect combination of factors such as water, rock base, gravity, and atmosphere together constitute the internal and external habitable environment for life on Earth. The probability of its occurrence is extremely low, which can be described as one in billions.

Do advanced extraterrestrial civilizations really exist?

As modern scientific research continues to deepen, scientists are increasingly convinced that in the vast universe, life is likely to exist in some form that we have not yet detected. In other words, the Earth is not the only place where life originated.

Especially in recent years, the discovery of "super-Earths" has shown that the external environment suitable for the existence of life is not unique to the Earth, which has triggered people's speculation about whether advanced civilizations may have been born earlier than human civilization.

Although this conclusion cannot be confirmed, it cannot be denied either. This uncertainty has stimulated scientists' enthusiasm and efforts in outer space exploration. In less than 30 years, more and more "super-Earths" have been discovered.

From "Gliese 581d" to "Gliese 667Cc" which is 9 times the mass of the Earth, "Gliese 163c" which is 49 light-years away from the Earth, and "Proxima b" detected in 2016, these "super-Earths" have gradually entered the human vision.

Some of these "super-Earths" have been confirmed by scientists to have no signs of life, while others are still under exploration, and the possibilities for exploration remain vast.

It is worth noting that most of these "super-Earths" were formed earlier than the Earth, and some were even 10 billion years earlier than the Earth. This means that if life does develop on these planets, the level of development of their civilization is likely to far exceed that of human civilization, which has also triggered discussions on the pros and cons of discovering advanced civilizations.

The famous astrophysicist Stephen Hawking once warned in his book: "Don't have any illusions about alien civilizations. Perhaps when we are exposed to them, it will be the moment when human civilization comes to an end."

Reference sources: CCTV News, Huanqiu.com, Zhang San's Science Notes