Where did life originate? This question has puzzled scientists for many years. Although it has been claimed since biology classes in middle school or science classes in elementary school that life on Earth originated in the primordial oceans, this is only one claim. For now, the idea that life on Earth originated in the primordial oceans is just a scientific conjecture.
Therefore, regarding the origin of life on earth, there are also theories that life on earth actually came from outside the sky. Of course, if this statement is true, then all creatures on Earth can be considered extraterrestrial visitors.
1. Primitive life
From the perspective of the history of science, it is not uncommon in the history of science for scientific theories to be overturned and new ones to be produced. So, while the current belief that primitive life came from primordial oceans is considered the dominant idea, that doesn't mean that this theory won't be overturned.
For example, for many years, there has been a theory in the scientific community that the primitive life on Earth came from meteorites. For example, in Australia, humans have found that there are amino acids in meteorites, and if these amino acids fall into the primeval ocean, life can be derived in the environment of the primordial ocean.
Of course, this theory is also constantly being improved. For example, in recent years, some scientists have suggested that primitive life on Earth may have come from comets. Because comets carry molecules of organic matter, these molecules can also give birth to life in the oceans of the primitive earth.
2. Landing 67P/Churyumov-Gerasimenko
In 2014, the European Space Agency probe successfully landed in a program called 67P/Churyumov-Gerasimenko. The composition of the comet is then collected and tested, and the data is sent to Earth.
The reason why 67P/Churyumov-Gerasimenko was chosen as the landing object is because the comet was formed 4.6 billion years ago. At that time, the solar system was also just forming. Therefore, judging from the qualifications, this comet can be called the patriarchal existence of the solar system. And comets are essentially dirty snowballs. This means that in this comet, a lot of the original material from 4.6 billion years ago should have been preserved.
That's why the probe chose to collect and detect the comet's composition. Finally, it was determined that there were many amino acids on this snowball that were involved in the production of life. And this discovery also means that the belief that comets hit the Earth, bringing amino acids to the Earth and giving rise to primitive life, provides a possible and practical basis.
3. The possibility of extraterrestrial life
It is also because comets are widespread in the solar system. Therefore, scientists believe that in the solar system, on planets suitable for incubating life, it is entirely possible that there are microorganisms. However, due to the limited detection capabilities of human beings at present, it has not been possible to determine whether these extraterrestrial worlds are really living microorganisms.
Take Mars, for example. Although at the moment mankind considers Mars to be a desolate planet. But there are ice caps at the north and south poles of Mars. The presence of microorganisms beneath the ice sheet is something that scientists cannot determine and needs to be detected in the field. In addition, satellites with subterranean oceans (e.g., Europa, Europa) may also have microorganisms. So, humans have also considered sending probes to Europa's underground ocean.
Of course, nothing is more of interest to mankind than Titan. Because there is a lake on Titan, this lake may be able to become a breeding ground for Titan's primitive life.
Of course, these are all scientific conjectures at the moment. If you want to verify, perhaps, it will take until 2124 to draw conclusions.
Thinking that life is short and not seeing what comes after it has to make people sad.