Over the past few decades, mankind has discovered thousands of extraterrestrial planets by various means, some of which are considered terrestrial planets, that is, planets with similar characteristics and conditions to Earth. These terrestrial planets have become the best candidates for human search for habitable planets and extraterrestrial life.
Among these terrestrial planets, there is one that stands out in particular, and it is called "SuperEarth", which is called Kepler 22b. Located in the constellation Cygnus, about 600 light-years from Earth, this planet is a terrestrial planet located in the habitable zone, and scientists**, Kepler-22b has a temperature and environment similar to that of Earth, and is considered a possible second home for humans.
The Kepler Space Telescope uses the transit method to observe the occlusion effect of stars as they pass in front of them. By measuring changes in the light of stars, it is possible to estimate the existence, size, and orbit of traveling stars.
The discovery of Kepler-22b was not easy, after all, the Kepler space telescope observed in the directions of Lyra and Cygnus contains about 150,000 stars. Almost every one of these stars has its own planetary system, and the number of planets located within the habitable zone is staggering.
In May 2009, the Kepler Space Telescope made its first observation of a star in the constellation Cygnus, named Kepler 22. This star is a yellow dwarf, very similar to the Sun, its mass and volume are almost a copy of the Sun, and even the temperature is about the same as the Sun, with a temperature of more than 5,000 degrees.
After observing the star's light curve, scientists discovered an interesting phenomenon, which is that the star's brightness decreases slightly every 290 days, lasting about 7 hours.
This means that the star may have a planet orbiting it, and the planet's orbit is exactly in the direction of our line of sight, so whenever it passes in front of the star, it will block some of the star's light, causing a change in the star's brightness.
Scientists are excited about the discovery because the planet's orbital period is about the same as that of Earth, which means that its orbital distance is about the same as that of Earth, which in turn means that it may be located in the habitable zone and may be a terrestrial planet. As a result, scientists named the planet Kepler-22b, which is the first planet of Keple-22.
More observations and verifications are needed to determine the planet's existence and characteristics. This is because the transit method can only measure the orbital period and size of the traveling star, but not the mass and density of the traveling star, nor can it determine the shape and composition of the planet. Therefore, scientists began to use Doppler spectroscopy to further study the planet.
Doppler spectroscopy uses the Doppler effect to observe the red and blue shifts of the star's spectrum with the motion of the planet, so as to calculate the mass and orbital inclination of the star. With this method, scientists can determine the authenticity and type of planet, such as whether it is a gaseous or rocky planet.
After more than two years of observation and analysis, in December 2011, NASA officially announced the discovery of Kepler-22b. They confirmed that the planet was indeed a terrestrial planet located in the habitable zone, and that it was about 2 times the diameter of the Earth4 times and the mass is also greater. If it is said that its density is the same as that of the Earth, then its gravity will also be 2 of the Earth4 times. That's why it's called "SuperEarth".
Of course, these data are based on assumptions and speculations, as scientists have not yet directly observed the true form and composition of Keple-22b. This also casts a layer of mystery over Kepler-22b.
Since Kepler-22b is a terrestrial planet, is it really habitable?
Let's start with its star Kepler-22. The star is a yellow dwarf star that closely resembles the Sun, and it has a lifespan of up to 4 billion years, although it is half the life of the Sun. But such a long life is enough to wait for the formation and evolution of planets, and it also gives life a certain amount of time.
Kepler-22 is also similar in volume and temperature to the Sun, which means that its luminosity and radiation are also comparable to the Sun. Then there is a high probability that liquid water is also present on Keple-22b.
The orbital distance of Kepler 22b is 085 astronomical units, which is slightly smaller than the Earth's orbital distance. This is because Kepler 22 has a slightly smaller luminosity than the Sun, so its habitable zone is also slightly closer than the Sun's. In this way, Kepler-22b is right within the habitable zone of the star, and according to scientists' estimates, the surface temperature of Keple-22b is about 22, which is higher than the average temperature of the Earth15.
In terms of temperature, the likelihood of Kepler-22b becoming a habitable planet has increased indefinitely. Next, let's take a look at the surface conditions of Keple-22b.
Although the information is relatively lacking, after all, scientists have not directly observed the surface features of Keple-22b, and can only speculate based on some indirect evidence and hypothesis.
The diameter of Kepler-22b is 2 of the Earth4 times and the mass is also greater. This means that its gravity can also reach 2 of the Earth4 times. This may be a disadvantage for humans, as human bodies and organs have evolved to adapt to the gravity of the Earth, and if they live under stronger gravity, they may cause various health problems, but this problem is almost negligible for the interstellar migration program.
The most critical factor left is Kepler-22b's atmosphere. The atmosphere is a very important factor because it not only protects the planet from cosmic rays and meteors, but also regulates the temperature and climate of the planet, and is able to provide oxygen and water for life, among other things. If Kepler-22b had an Earth-like atmosphere, or at least an atmosphere that was harmless to humans, then it would be a distance of liquid water from habitable planets.
Finally, let's take a look at the presence of water in Kepler-22b. Water is the source of life and a basic human need.
Scientists believe that life is possible only in the presence of liquid water. The surface temperature of Keple-22b is 22, which is a favorable condition in the range of liquid water. If Kepler-22b has enough water, then it has the potential to be a habitable planet and even have life of its own. If Kepler-22b has no water, or too little water, then it is not very suitable for human habitation, unless humans can obtain water from other sources, such as transporting water from other planets or moons, or extracting water from Kepler-22b's underground or ice.
Are you tempted by such a terrestrial planet with a suitable temperature?