The White House has issued a declaration in response to a petition signed by more than 5000 people, stating that the government has no evidence of extraterrestrial life existing outside the Earth.

The unusual declaration was made in response to a feature on its Web site, We the People, which mentions that government officials should respond to petitions if enough people signed on it.

Two of such petitions asked the government to disclose any details about extraterrestrials or contact with them.

In response, Phil Larson of the White House Office of Science and Technology Policy mentioned that the government had no evidence of any extraterrestrial presence contacting the human race. Moreover, he mentioned that there was no credible information to suggest that any evidence is being hidden from the public's eye.

At the same time, Larson clarified that there had been a number of projects studying the possibility of such alien existence or the lack of it.

Major organizations working towards this include the Search for ExtraTerrestrial Intelligence (SETI), NASA's Kepler spacecraft and the Mars Science Laboratory.

Initially set with the help from NASA, SETI is now mainly under private fundings and works to identify any signal from the outer world. On the other hand, the main aim of Kepler is to locate other Earth-like planets with potentially habitable environment.

The Kepler mission is specifically designed to survey our region of the Milky Way galaxy to discover Earth-sized, rocky planets in or near the habitable zone of the star (Sun) they orbit.

The post goes on to mention that many researchers and mathematicians have found out statistical calculations that point out the highly unlikely probability of alien contact, given the large distances involved.