On a clear night, when you walk onto the balcony and look up at the night sky, what kind of sight will you see? Billions of stars shine like lights in the dark night sky.
They are dazzling, mysterious, and evocative. Do you wonder if there are "people" on the stars hundreds of millions of light-years away, and if so, what are they like?
The search for extraterrestrial life has always been a major focus of scientists' research, in the fall of 2010, at the University of California, Santa CruzAstronomer Steven Vogt and his team have discovered a planet with characteristics similar to Earth's, there is likely to be life on it.
This extraterrestrial planet is called"Gliese 581 (Glazer 581g)"., about 203 light-years, compared to those planets that are hundreds of light-years away, it can be regarded as the "close neighbor" of the earth.
Glazer 581g is similar to Earth in all its characteristics, and is an exoplanet with a surface suitable for lifeIt has a mass of about 3-4 times that of the Earth, and its rotation period is 37 days, making it a rocky planet. Its parent star is a red dwarf star named Glazer 581, whose orbit is located in the "habitable zone" of the parent star.
The so-called "habitable zone" refers to the distance of the planet within a certain range of the parent star, just enough to allow its surface temperature to keep the water in a liquid state. Glazer 581g is located at a distance of 9.65 million kilometers from the parent star, which is much closer than the Earth to the SunBut the average temperature of its surface is between -31 and -12.
This is because red dwarfs release much less energy than the SunSo even if the Glazer 581g is as close as the parent star, the planet's surface still does not form an extremely hot climate.
The planet Glazer 581g is "neither too cold nor too hot" and its gravity is somewhat greater than that of Earth, which is enough to form an atmosphere on its surface. With the protection of the atmosphere, the water on the planet's surface can remain in a liquid formFormation of lakes, rivers, which most likely give birth to life.
Experts from NASA and the University of Washington deduced from the model that the energy radiated outward by red dwarfs was less than one percentIf photosynthetic plants were present in Glazer 581g, it is likely that their appearance would have evolved to be blackin an attempt to absorb as much "sunlight" energy as possible.
Due to the close proximity of the parent star of the Glazer 581gThis results in it being a "tidal locked" planet, always with only one side facing the parent star. The temperature on the "sunny side" may reach 64, and the "negative side" is permanently in extreme cold.
Scientists use the Earth-like Index to express how similar a planet is to Earth, which involves multiple factors such as volume, density, and temperature. Using Earth as a reference, the index is up to "1", and Earth's neighbor Mars is "0."7", while the Glazer 581g is "089“。
Although the Glazer 581g is very similar to Earth,But it is a controversial planet, and many scientists believe that it does not exist. Just two weeks after the discovery of Glazer 581g was announced, Swiss astronomers said that after analyzing the subtle changes in the gravity of the main star Glazer 581 and the planet around it, there is a high probability that Glazer 581g will not exist in the entire planetary system.
In 2011, Canadian astrostatisticians, demonstrated through a detailed model analysis reportThe probability of error in the conclusion that "Glazer 581g exists" is 999978%。
In 2014, Paul Robb, an astronomer at the University of Pennsylvania in the United States, pointed out that not only Glazer 581g, but also another planet in the planetary system, Glazer 581d, did not exist. The data detected by the original spectrometer may be incorrect, both planets are the main star magnetic field eruption, resulting in light error imaging, and these two stars do not exist in the planetary system.
At present, the academic community is still controversial about the existence of Glazer 581g. If the planet does not exist, it means that hope for extraterrestrial life is dashedBut all this is yet to be further explored by scientists.
At present, humans have widely searched the solar system for signs of the existence of primary life, including planets such as Mars, Enceladus, Europa, and Titan. Scientists generally agree that intelligent life should exist outside the solar system.
In 2010, American astronomy doctor Frank Drake arguedThere should be at least 10,000 advanced intelligent civilizations in the galaxy. So this doesn't explain why these civilizations have been silent in the universe?
Astronomers have given many explanations for this. For example, we humans don't know what frequency to use to receive signals from aliens, or we don't know the direction of the source or the time it will arrive on Earth. It is also possible that aliens will communicate in ways that we humans don't know about, more advanced than human means of communication.
Some scientists have theorized that hundreds of millions of years ago, there were frequent ray bursts in the Milky Way, and that dead star collisions and black holes could have released rays, but only now that such collisions are rare. There are no extraterrestrial civilizations on Earth yet, and it is likely that extraterrestrial civilizations died of radiation during the journey. **10,000 Fans Incentive Program Life on Earth originated 3.5 billion years agoIt took 1.7 billion years of long evolution for multicellular organisms to emerge. Human civilization came even later, and humans did not begin to explore space until the last century.
It takes a long time for life to develop intelligence, so the probability of human beings encountering intelligent civilizations that can communicate is very small, if there is extraterrestrial lifeThey will most likely be rudimentary life forms.
The Glazer 581g whetted the appetite of astronomers, and the controversy surrounding the planet has never stopped. If this planet does exist, it will be of great significance to humanity. Astronomers estimate that there are at least 2 billion terrestrial planets in the Milky Way. With such a large number, there will definitely be intelligent life on some planets.
In 2014, experts from the California Institute for Extraterrestrial Life saidWe should continue to point our antennas at the sky to detect the signalIt is expected that by 2040, astronomers will complete the search for a sufficient number of planets, and it is likely that electromagnetic signals from extraterrestrial civilizations will be detected at that time.