The newly discovered water world "Super Earth" is only 40 light years away from our planet.

If Earth-like planets hundreds of light-years away from the Earth are discovered through advanced human technologies such as Kepler telescope, how can we judge whether there is life on their planets?

In the process of searching for Earth-like planets, we should first screen them. The most suitable one is a smaller planet with a rocky surface and suitable temperature. Water can exist in liquid form, and they must revolve around a stable star like the sun.

Because life takes a long time to evolve, and the sun is 4.6 billion years old, there is no sign of life in the earliest 800 million years of the earth. Later, after 3.8 billion years of slow evolution, intelligent life like human beings appeared.

After this round of screening, the atmosphere of planets really similar to the earth can be analyzed by spectrum. Light from the stars behind the planet will pass through the planet's atmosphere,

Through the spectral analysis of these rays, if oxygen and methane are found in the atmosphere, then the planet may have life characteristics, because the coexistence of oxygen and methane in the atmosphere is a sign of life. When the oxygen content in the atmosphere is high, methane can be converted into water and carbon dioxide with high efficiency, and it is difficult to exist for a long time. If oxygen and methane are detected in the planetary atmosphere at the same time, it means that methane enters the atmosphere very quickly, and a steady stream of methane may come from the activities of life. Such as swamp bacteria, rice planting, plant burning, flatulence of cattle and natural gas from oil wells (from the remains of ancient plants) and so on. Therefore, methane may be a sign of life in an oxygen-containing atmosphere.

At this time, large radio telescopes and optical telescopes can be used for further detection to detect whether the planet has special radio waves or laser signals, so as to judge whether there are extraterrestrial intelligent life entering the scientific and technological civilization.

In the universe, binary numbers may be basic numbers, that is, "universal language." If you can receive special radio waves or laser signals, and they are prime numbers of binary numbers, such as 1679, you can analyze the precious information sent by aliens by arranging them in 73 rows with 23 numbers in each row.

Astronomers have a great debate about whether there are planets in the Milky Way that have entered the technological civilization. Now everyone is counting on Kepler telescope to see if it can turn a new page.

Kepler mission searched the Milky Way for Lyra and Cygnus. Coincidentally, however, Vega in China's Millennium myth is the brightest star in Lyra. Maybe in a few decades, we will receive a "short message" from a distant alien "Weaver Girl".

Now astronomers have found water and other liquids not only on other planets inside the solar system, but also on distant celestial bodies outside the solar system.

The journal Nature published in June 5438+February 65438+June 2009 reported that Chakri Berta, a graduate student and astronomer at Harvard-Smithsonian Center, discovered a "super earth" revolving around a dark star.

The newly discovered planet is named "GJ 12 14b". It is only 40 light years away from the earth, and it is a steaming water world. GJ 12 14b is 2.7 times the diameter of the earth, 6.6 times the mass of the earth and one third of the density of the earth (the average density of the earth is 5.5 times that of water). Therefore, we can know that three-quarters of this planet is water, and there may be an ocean with extremely high depth. There is also evidence that this water world also has an atmosphere. Astronomers believe that this planet is closer to the earth than any planet found outside the solar system.