There are many Earth-like planets in the universe known as "terrestrial planets" or "super-Earths" that have Earth-like rocky surfaces, atmospheres, and possible conditions for the presence of liquid water.
In the vast universe, there are countless planets similar to the earth. In the case of the Milky Way, for example, there may be nearly 1 billion terrestrial planets. Although many terrestrial planets have been discovered by humans, these are only a small fraction of the terrestrial planets in the universe. Terrestrial planets are difficult to discover because extrasolar planets are not as easy to observe as stars, and they usually require a long period of observation and calculations using relevant knowledge such as astrophysics and astronomical theory. As a result, the number of planets in the universe that are actually similar to Earth is far beyond the scope of current human observations and known data.
Here are some of the planets that are similar to Earth:
1. Kepler 452b
Kepler 452b, located about 1,400 light-years from Earth and about 1.6 times the diameter of Earth, is considered a close relative of Earth.
2. Kepler 186f
Kepler 186f is located within the habitable zone, about 1.1 times the diameter of the Earth, and may have a similar atmosphere and natural environment to the Earth.
3. Kepler 438b
Kepler 438b is located in the constellation Pastor, 470 light-years from Earth, with a radius of about 1.1 times that of Earth, and a surface temperature of about -14°C, which is similar to the average temperature of Earth.
4. Gliese 581D
Gliese 581d, located about 20.5 light-years from Earth, is considered one of the most likely planets to harbor life outside the solar system, with the possible presence of liquid water on the surface.
5, Mars
Mars, although it is now an icy red planet, scientists believe that there may have been liquid water on the surface of Mars at some point in the past.
6. Europa
Europa, where a vast ocean may be hidden on the surface, may have a mechanism similar to that of the Earth's plate tectonics, which allows liquid water to flow under the ice.
7. Titan
Titan, with its vast nitrogen atmosphere, may have a mechanism similar to that of the Earth's plate tectonics, which allows liquid hydrocarbons to flow beneath the surface.
The discovery of these planets has increased scientists' confidence in the search for the possibility of extraterrestrial life. However, due to technological limitations, human beings are still quite rudimentary in their observation of the universe and are unable to set foot in space on a large scale.