Findings of a latest national survey undertaken by CNN/ ORC International show that as many as 79% of Americans believe that all the 239 passengers of the ill-fated MH 370, which disappeared mysteriously en route flight from Kuala Lumpur to Beijing on March 8 are dead, but still a majority of the respondents are of the view that the search for the Boeing 777 and its passengers should continue.

Some respondents have, however, questioned whether the investigation was being carried in the right direction and even if the search for the missing plane was taking place at the correct location.

To date no evidence or wreckage from the missing plane has been found, prompting the U.S. Navy to continue to support the search for another four weeks.

The search will now emphasize on the southern Indian Ocean. Bluefin 21, an unmanned Australian submarine, is already exploring the ocean floor in the region.

As many as 46% of people are of the view that we will never know what exactly happened to Flight 370.

During the survey, respondents were also asked about their views on the potential causes of the flight disappearance, including an accident or mechanical failure.

The New York Times reported that 66% respondents believed that a pilot or flight crew member could be to blame, while 57% said a terrorist attack was plausible.

Most surprisingly, 9% respondents said "space aliens, time travelers or beings from another dimension" were "very likely" or "likely" to have caused Flight 370 to vanish - buying into one of the main conspiracy theories to have been promoted online since the tragic incident took place.

The poll was conducted as a phone survey of 1,008 adult Americans from May 2 through May 4.