Could there be Earth-like planets in this universe? The answer may be, because NASA has found several planets that are very Earth-like and are believed to have water sources like those in this world.
It is also believed that it is not only similar to Earth in terms of shape and structure, but also can be inhabited or inhabited by humans. Meaning, Earth is not the only planet that can be inhabited by humans.
In the Milky Way galaxy itself, there are no habitable Earth-like planets. Earth is the only planet that makes it possible for humans, animals, and plants to live and reproduce. You must have memorized how the Big Bang theory caused the solar system to occur billions of years ago. You are also familiar with the process of the occurrence of land on this Earth.
Earth itself is an extraordinary mystery to its inhabitants. Pythagoras, a Greek mathematician, believed the Earth was round, while almost everyone in his time believed the Earth to be an abyss. It took more than a thousand years to prove Pythagoras' belief. And the credit for proving it is Magellan, the sailor who managed to circumnavigate the earth in search of spices.
The Earth-like planet is named Kepler 22. It is estimated that the temperature on the rocky planet's surface reaches 72 degrees Fahrenheit, the equivalent of spring temperatures on Earth. Research is still being done because the distance of this planet from Earth is not close. At least, it took 22 million years to get there with the technology that humans have today. An unimaginable distance away.
Physically, Kepler 22 is considered the most Earth-like. This Earth-like planet is already showing signs of life although it remains to be confirmed further. Earth itself has a volume of about one million square kilometers with a surface reaching five hundred and ten million square kilometers. The temperature of the Earth's interior is estimated at six thousand degrees Celsius.
On Earth, the life of living things has existed since three and a half billion years ago. At that time, all living things in the sea, until then bacteria undergo changes and form green plants. Later this green plant uses sunlight to form oxygen. Then, began to create mammals, various types of birds, to continue to grow as we see today.
Various studies provide a lot of knowledge for us. For example, how the Earth and other planets revolve around the sun. This is due to the attraction between them. The force of gravity itself became one of the most important discoveries of Sir Isaac Newton.
The theory that the Earth revolves around the sun is also an important theory because humans previously thought that the sun revolved around the earth. Perhaps this is based on the fact that the sun always rises in the east and sets in the west. The movement of the sun made ancient humans conclude that way.
It is not known for sure whether the Earth-like planet has two or four seasons. Meanwhile on Earth, the northern and southern hemispheres, there are four seasons, and at the equator only has two seasons.
The difference in the number of seasons on the Earth's surface is caused by the tilt of the Earth's axis. This causes the amount of sunlight received by the earth's surface to vary. While the equator is always showered with the same amount of sunlight throughout the year.
Earth is the only planet that has an ideal temperature and abundant water sources, so that it can be inhabited by living things. Mercury and Venus, which are very close to the sun, are not ideal places to live. There was no sign of life there because the temperature was too high.
Then, there is the planet Mars, also known as the red planet. This planet was expected to be a human habitation other than on Earth. However, it was later discovered that the condition of this planet was not possible to live in.
Then, there are several planets after Earth that are also impossible to live on. Jupiter, Saturn, Uranus, and Neptune have very extreme temperatures. In addition, the planets beyond Earth do not have oxygen that humans and other living things can use to breathe. Without oxygen, all living things will die.
1. Kepler 22
The planet Kepler 22 was discovered by NASA. This Earth-like planet orbits a star smaller than the sun. Like Earth, Kepler 22 also has its own orbital line.
This planet orbits for 290 days and is considered to make the planet's temperature suitable for life. The time of its orbit is also considered not to have much effect on the air temperature there. Maybe because the center of the solar system is not as big as the sun.
Astronomers believe that Earth-like planets are already inhabited. This supports the theory of the existence of other creatures besides humans in this universe. So, making sci-fi films like ET is no longer impossible.
The planet Kepler 22 is estimated to be larger than Earth, which is more than twice the size of Earth. The surface of the planet itself is quite diverse. There are surfaces that look rocky, there are also other parts that are filled with shards of ice and water. Could there be a Pandora planet like the one presented in the Avatar movie?
2. Gliese 581g
Observatory observations in Hawaii for eleven years resulted in the discovery of an Earth-like planet again named Gliese 581g. The planet is believed to be habitable for humans and other living things. Moreover, it is known that even liquid substances can still exist on the surface.
This planet is considered to be the most Earth-like planet compared to other planets that have been discovered. Interestingly, this planet has a mass between 3 and 4 times the mass of Earth. Its orbital period is also very short, less than 37 days.
It is estimated that the temperature on this planet ranges from minus 31 to minus 12 degrees Celsius. The gravity on this planet is estimated to be equal to or even greater than Earth's, making it easier for humans to walk upright on the earth's surface. Gliese 581g is not as far away is Kepler 22, which is about 20 light years from Earth.
3. Kepler 9
Then, there are the Kepler 9 planets in a planetary cluster that has never been found before. The results confirmed the existence of two Saturn-sized planets orbiting a star. The two planets are quite far from Earth, which is about 2,300 light years. The two twin planets were later named Kepler 9b and Kepler 9c.
However, the two are not like Earth because the temperature is too hot. However, in the vicinity of the two found another planet that is smaller and is believed to be similar to Earth. However, further research is still needed to confirm this. And of course it's not an easy thing to do.
The search for Earth-like planets and other planets continues to be carried out by astronomers. The reason, of course, is almost uniform, namely to uncover the secrets of the universe which is full of mysteries.
Later, it is estimated that there are billions of Earth-like planets that can be inhabited because they have water, oxygen, and gravity. However, it is not easy to get there because it requires high technology to do so.
Seven planets around the Earth alone can not be visited and studied due to various obstacles. Hopefully information about the world of space continues to be accompanied by technological advances so that travel to other planets does not become just a fantasy.