Why humanity has not yet encountered extraterrestrial life: scientists' opinion## Translated content from Russian to English as requested, maintaining the original formatting and providing an accurate translation of the title.

The question of the existence of extraterrestrial life remains one of the main scientific mysteries. Despite billions of planets in the Universe, there is still no official confirmation of contact with aliens.

Scientists name several possible reasons:

1. Civilization filters. According to the "great filter" hypothesis, intelligent life forms may self-destruct before reaching a cosmic level of development. Perhaps we are the first who managed to pass through this filter.

2. Different time scales. Civilizations could have existed millions of years ago or will appear millions of years from now - they simply didn't coincide with us in time.

3. Lack of technology. Our technology is too primitive to detect signals or life forms existing in another biochemical form.

4. They are hiding. Some theories suggest that extraterrestrial civilizations deliberately avoid contact - for ethical or strategic reasons.

While science continues the search, this question remains open. But each new telescope, each probe, and each investigated signal brings us closer to a possible answer.