1. Is there any factual evidence that the Earth have been visited by other civilization?
2. Is important to explore the Universe looking for signals from other civilization?
3. Make a quick research about SETI institute. Is its mission important nowadays?
Are we alone in the vast universe? This a very polemic question. Most of Scientist (Astronomers, Physicists, Biologists, etc.) state that no civilization has visited our planet. Nevertheless Prof. Abraham Loeb* has written a book describing the visit of an interstellar object called “Oumuamua” that passed 15,040,000 miles from Earth; it is opinion of Prof. Loeb that the object is a piece of advanced technology created by a distant alien civilization.
Prof. Loeb based his hypothesis on the facts that Oumuamua was moving to fast along a strange orbit, it left no trail of gas, and the shape of the object was unusual.
Long time before of the discover of Oumuamua, the astronomer Frank Drake** formulated an equation to estimate the number of civilizations in our galaxy that we might be able to communicate with.