Im an international student and i am having a difficulty to understand this passage. can someone explain it to me with more basic english

There is a lot evidence that proves that extraterrestrials (aliens) are visiting earth and are currently in our atmosphere (air). there is so much proof of this that nobody even realizes it. the government and religious leaders deny/ refuse to believe all of it. even most of the people in the science profession deny it because of the “social stigma” (the bad reputation of the topic).

Uh