Scientists believe there is 100% life? Super Earth Gliese 581g is constantly controversial, is it very special?

In recent years, there has been a planet that has not only been under observation for a long time, but has also been considered by scientists to have a 100% possibility of life. Where is this planet?

Gliese 581g, known as a potential super-Earth candidate planet, is the protagonist of this article, but there are still many controversies about it.

What’s so special about Gliese 581g?

Why have scientists been observing it for so many years?

Is there really life in it?

Will humans be able to immigrate here in the future?

There are many questions about Gliese 581g. The following article will mainly describe why Gliese 581g is considered to have 100% life based on astronomers’ research reports on it, and briefly answer the questions. these questions.

The development of cosmic objects and astronomy has given ordinary people the opportunity to understand the entire universe, especially people's longing and imagination for "outer space immigrants". This makes some tasks of astronomy no longer exclusive to scientists.

Anyone can discover new planets or settlement zones through their own observations and submit them to the Habitable Exoplanet Catalog.

The catalog contains habitable worlds discovered by ground and space telescopes over the past decade, including Gliese 581g.

This planet was discovered by Steven Vogt in September 2010 during the Carnegie Institution's Exoplanet Survey.

Researchers used Doppler spectroscopy to observe the Doppler frequency shift in the spectrum of the planet's parent star and used radial velocity measurements to search for extraterrestrial planets, and thus discovered Gliese 581g.

Data shows that Gliese 581g is only about 20 light-years away from the Earth, is located in the habitable zone, and is 1.3 times larger than the Earth.

If we look at the current speculation on life forms and the environmental requirements for the formation of life, this means that there may be liquid water on its surface, and it will become a super Earth with life.

When Dr. Vogt was asked at the press conference about the possibility of life on the planet Gliese 581g, he believed that the planet was in the habitable zone, although Gliese 581g is cold on one side and hot on the other. , but there should be a balance zone between them, where there will be a suitable area for life to develop.

According to his and his colleagues' estimates, Gliese 581g's average surface temperature is between minus 12 degrees Celsius and minus 4 degrees Celsius, which is roughly the same as the temperature of a day in Antarctica during the summer.

At the same time, Dr. Vogt also said that he is not a biologist. At this point, he believes in his astronomical data and from an astronomical perspective, he believes that there is life on this planet. The possibility is 100%.

In addition, colleague Dr. Butler also believes that as long as the data is sufficient and the planet is so close to the earth, it is very likely that more discoveries will be made in the future.

However, as a science, astronomy also requires a rigorous attitude to look at the universe. For the discovery of extraterrestrial planets, any potential planet, whether life or not, requires multiple observations. The final judgment can be reached by comparing and analyzing the data.

Therefore, Dr. Vogt and his team are not the only ones working on this project.

In Geneva, the astronomy team led by Francisco Pepe raised questions about this through comparative studies based on data observed by the High-Precision Radial Velocity Planet Searcher (HARPS).

Just two weeks after the announcement of Gliese 581g, a research team in Geneva questioned the existence of Gliese 581g and doubted the authenticity of the discovery.

The reason is that when they called the data obtained by HARPS, they found that although the instruments they used were very precise and had many data points, the signal amplitude of the planet detected by HARPS was very low, basically in a measurement noise. level.

Why does this happen?

According to MIT astronomer Sarah Seager, the difference between the two sets of results may be due to the different orbital characteristics of the planets assumed in the calculations.

The orbit hypothesized by the Vogt team for Gliese 581g is considered to have a perfectly circular orbit, while the Geneva, Switzerland, team believes that this orbit is more eccentric.

Therefore, the Geneva team believes that what the Vogt team saw were the signals of the other four planets in the system, not the signal of Gliese 581g.

By 2011, such differences had become even more serious.

Not much information was previously known about Gliese. People only believed that the planet was in the habitable zone and suitable for habitation. However, it may not exist due to information interference.

A 2011 survey believed that the tidal locking phenomenon of Gliese 581g caused scientists to rethink the possibility of life on the planet.

Tidal locking makes the orbital motion of Gliese 581g like Mercury in the solar system, so the time distribution on the planet is in polar day and polar night.

If the temperature in the polar night area is too low, carbon dioxide and the atmosphere will not be in a stable gaseous region, and ice crystals will appear on the surface.

At the same time, because they cannot receive sunlight and are heated, they cannot be released into the atmosphere, so they may become cold.

In order to better understand what it looks like on the planet Gliese 581g, a scientific research team from the University of Paris conducted a simulation analysis.

The team hypothesizes that the climate is mainly affected by the greenhouse effect of carbon dioxide and water. This assumption is applicable to rocky planets with important atmospheres in the galaxy.

After multiple iterations of research, the simulation showed the Gliese 581g star with different atmospheric pressures and different compositions.

If the atmospheric environment is less than 1 MPa, then atmospheric collapse will occur, which is the situation mentioned earlier.

If a liquid water ocean is added, this situation will be alleviated, and the critical point of air pressure will be stabilized at about 1 MPa.

This study theoretically proves that the Gliese 581 system where Gliese 581g is located has the possibility of being habitable. This is like a stabilizing shot for previous studies. Gliese 581g seems to have ignited new hope for people.

In 2012, Vogt’s research team reused the data of the Swiss team and brought the data into a circular orbit. Gliese 581g reappeared in front of people’s eyes again.

Vogt said the Geneva study may have omitted certain data points from the original paper and that they used circular orbits because of their dynamic stability, goodness of fit and Occam's razor can take effect.

Taken together, scientists have discovered the tidal locking of Gliese 581g in the past few years. The atmospheric system simulation iterations, including its observation data, are in a state of repeated changes.

At the same time, the planets b, c, d, and f surrounding it have also made many scientists doubt whether the habitable zone of the planet is real and effective. After so many years, the observation of planet Gliese 581g has entered To what point?

Obviously, the seemingly non-existent planet like Gliese 581g is its biggest controversial point. Several asteroids in the same group also have to make scientists think about whether the Gliese 581 system is effective.

Pennsylvania State University pointed out in a 2014 study that sunspot activity can sometimes "disguise" as planetary signals. Previously, it was difficult to infer the existence of Gliese 581g by observing the orbit of Gliese 581d. There may be problems.

If when observing it, the signal of 581d is not itself, but comes from the activity of sunspots, then based on such observations, neither Gliese 581d nor 581g will exist.

Such statements are constantly shaking people's confidence, but researchers firmly believe that the existence of this planet is real, which gave people confidence again in the 2015 study.

Researchers at the University of Hertfordshire believe that such problems occurred entirely due to insufficient technical analysis in the past.

In the 2014 study, the statistical research techniques used to explain stellar activity simply could not identify asteroids like Gliese 581d well.

The research team believes that the previously used methods are effective when identifying relatively large planets, because they have a great impact on stars and stellar activity is not enough to interfere with their signals.

The researchers used a more accurate model of the existing data and are confident that Gliese 581d's signal is real.

Although there will be variability in planetary signals, this makes people realize that such asteroids require more and more precise signal and model analysis to determine the possibility of habitability.

Research on the Gliese 581 system is still continuing, and many scientists believe that the Gliese 581g planet is real.

It is really close to us, only 20 light-years away. Compared with those planets that are hundreds or even tens of thousands of light-years away, the Gliese 581 galaxy is undoubtedly what people are looking for. That outer world.

This is what makes it special - belief.

In the future, Mars, the moon, and Gliese 581g are all potential habitats for humans, and they bring another possibility to humans.

Precisely because people believe that their existence will bring changes to the future, scientists work tirelessly to find those planets that may bring faith to mankind.