This is the biggest unanswered question for decades- Have the outsiders lived in the solar system in front of man?
Now, an American scientist believes he has an answer to that.
Professor Jason Wright claims that extraterrestrials could live on one of the planets of our solar system before they disappear without traces, transmits Indeksonline.
Professor Wright is an associate professor in astronomy and astrophysics at the State University of Pennsylvania.
In a book he says ancient people may have life on Mars, Venus or even on Earth.
Wright says there is a chance to quickly find technological part left behind by extraterrestrials.