The Earth is gradually vanishing from the view of any aliens that might be looking for us, because we are using fewer technologies that leak radio waves into space.

This is the view of one of the pioneers of the SETI project (that stands for Search for Extra Terrestrial Intelligence, in case you just crash landed), Frank Drake.

His remarks cast doubt over the current search methods employed by SETI in their hunt for little green men, but, he says, also suggest a reason for the deafening silence out there.

According to New Scientist our transition from radio tranmissions to cable TV could mean that our window of detectability is no more than 100 years.