𝔸𝕊𝕋ℝ𝕆ℕ𝕆𝕄𝕐:𝔾𝔸𝕋𝔼𝕎𝔸𝕐 𝕋𝕆 ℍ𝔼𝔸𝕍𝔼ℕ

     ~𝔸𝕤𝕥𝕣𝕠𝕄𝕦𝕠𝕟  𝕂𝕦𝕜𝕚

Scientific method consists of observation, conceptual ideas, hypothesis, theory, prediction, and experimentation. If the theory doesn't meet with experiments more data should be collected or get discarded it however if the theory satisfy experimentations more predictions will be done.

Sciences like chemistry/ biology are confined within a laboratory. Almost all the experiments/observations are carried out inside microscopic level with the help of instruments like microscopes. Errors and limitations can be detected easily in this case.

However, in case of astronomy experimentation is done through observation at a distance of light years or astronomical unit between two bodies in a universe with the help of instrument like telescopes.For example, Galileo Galilei was the first person observing the night sky to support the heliocentric model or Copernicus model meaning all the planets revolve around the Sun. Before accepted heliocentric model by the Catholic Christians, Tycho Brahe, Johannes Kepler, Bruno had done immense collection of data for evidence. In other words, astronomy has plethora mistakes but can be corrected by collection of huge data.

Just because ancient people constructed Stonehenge, Chicken Itza, the Great Pyramid doesn't proof the evidence of  ancient astronauts or extra terrestrial Intelligence. The universe is about 13.7 billions years ago  but none of the aliens were shown into the world. If they were the one constructed where is their footprints or evidence based reasoning.

If they were really advanced than us they must sent signals back through the Search  for Extra Terrestrial Intelligence (SETI). There must be some evidence left by them, if really exists. If their technology is quite backward it means communication will be quite difficult. Either way we have not enough evidence to say aliens exists.

If the aliens descended from a race of intelligent dogs, then their language would reflect smells rather than visual images. If they descended from intelligent birds, their language may be based on complex melodies. If they descended from bats or dolphins, their language may use sonar signals. If they descended from insects, they might signal one another via pheromones. Therefore, whatever is the case we have zero evidence that ancient astronauts or aliens artifacts those astronomical monuments or functions.