Top ten alien planets

The top ten alien planets are the planets where aliens may exist. These planets are as follows:

1, Mars. The barren and arid land on Mars has turned people from looking for little green men on Mars to looking for simple life forms. However, there is evidence that Mars once had a warmer and wetter past. Dry riverbeds, polar ice sheets, volcanoes and minerals that can only form in water are all found on Mars. In 2008, NASA's Phoenix rover sent back photos of the ice it found. This is an important discovery in the search for liquid water, which is a key element of life.

2. Europa. Europa's cold environment seems unsuitable for life. In fact, it may be not only the home of simple microorganisms, but also the home of complex life. After years of argumentation, scientists believe that there is an ocean hidden under Europa's ice, which even contains oxygen.

3. Callisto. Scientists from NASA once characterized Callisto as "a dead satellite", and it was not until they discovered that there might be a salt water ocean under its surface that they changed this view. Scientists think Callisto may have an ocean to cushion this effect. Considering the hypothesis that there may be life if there is water, astronomers believe that if there is such an ocean, there is likely to be complex life on Callisto.

4. Titan. Scientists have made a closer observation of Titan, and they have found more and more possible basic components of life, even though the surface temperature of Titan is as low as MINUS 300 degrees Fahrenheit (about MINUS 149 degrees Celsius). 20 10 in may, two groups of scientists claimed that the Cassini probe of NASA found that there were conditions for the combination of hydrogen and acetylene on titan. If these conditions are taken into account, Titan may really have life.

5.Enceladus. In 2005, when Cassini flew over the surface of Enceladus at a close distance, it found a geyser spewing ice and gas, and detected carbon, hydrogen, nitrogen and oxygen in it, which are the keys to supporting biological survival. In addition, the temperature and density of these plumes indicate that the environment under Enceladus' surface may be warmer and wetter. However, scientists have not confirmed the existence of life.

6. Exoplanets. Some estimates show that there are about 400 billion stars and countless exoplanets in the Milky Way, and these data are only estimates in the Milky Way. Therefore, there may be billions of livable celestial bodies in the universe. Exoplanets are planets located outside the solar system, which revolve around their respective main stars. In the atmosphere of "HD 209458b" exoplanet, water, methane, carbon dioxide and other substances are found, which are the key elements of life.

7. Orion Nebula. In a star-forming region of the Milky Way, it was recently discovered that it might find extraterrestrial life. 20 10 in may, the "herschel" space observatory of the European space agency announced that the Orion nebula, about 1500 light-years away from the earth, showed signs of organic chemicals with life. By analyzing the data observed by astronomical telescopes, astronomers can detect the signals of different substances and molecules that sustain life, such as water, carbon monoxide, formaldehyde, methanol, dimethyl ether, hydrogen cyanide, sulfur dioxide, sulfur dioxide and so on.

8. The dying red giant. In 2005, a research team composed of astronomers from many countries found that the dying red giant star may be like a defibrillator, bringing this cold planet back to life. Scientists believe that this rebirth may also lead to the formation of a new living environment.

9. Kepler 22b. Kepler 22b is the first planet suitable for human habitation. Its diameter is about 2.4 times that of the earth, and it is about 600 light years away. Although its diameter is much larger than that of the earth, its period of revolution is about 290 days, almost the same as the diameter of the earth. The central star revolving around it is very similar to the sun. It is also a yellow dwarf with spectral type G, but its mass is slightly smaller. The surface temperature of this planet is about 70 degrees Fahrenheit (equivalent to 2 1 celsius), which is very suitable for living, or it may be a warm ocean planet.

10, HD 85512b. HD 85512b are located in the constellation Vela, orbiting the orange dwarf. According to the data obtained by HARPS, the mass of HD855 12b is 3.6 times that of the Earth, and the distance from the parent star allows liquid water to exist on the surface. Scientists say that the existence of liquid water is crucial to the formation of life. The cloud coverage of HD855 12b is at least 50%, which indicates that it can reflect enough energy into space to prevent the surface from overheating. Usually, the cloud coverage of the earth is 60%.