Governments are aware and talking to them, but do not want to cause panic.  It is inconcievable that a highly developed race would come in a flimsy craft like in Roswell.  Possible concern is overpopulation of the planet, Zika virus, Muslims fighting each other and environmental disasters seem to be all attempts to slow the growth of population.  It is likely that there was a problem to locate our planet in space and time when the first attempts were made.  There is no time sequencing in their appearance, hence the historical records which show their visits in the past.  It must have been difficult to callibrate the location of our planet from distant future, so the records of their appearance are not chronologically in sinc.  Governments must be aware of this but had to keep the information secret not to cause panic.  I believe all this will be revealed soon, like next year.  Anton Stavik [email protected]