The Carpenters did a lot of covers. This was one of them.
But we're not talking about the cover. We're talking about the Klaatu original. You see, Klaatu was a band, formed in 1973, whose style had them dubbed "the Canadian Beatles". It was even rumoured that they WERE The Beatles for a while. Clearly, they weren't, but they had a few hits in their own right.
And they sure did write some offbeat music. However, the title was lifted from an actual 1950's UFO society who used that phrase to start every transmission.