Is it time for humans to

Journey to explore space to answer the question "Are people lonely in the universe?" still difficult.

Nearly 60 years after the astronaut Yuri Gagarin made the first flight into space in 1961, opening the era of human conquest of space, humans have so far been searching for answers to the big problem. : People have loneliness in the universe?

For 40 years of waiting, humanity has yet to find aliens.

Many countries have invested in gray matter, money, technology . to serve the exploration of the universe; searching for "new land" hidden and nourishing alien life; Successful communication with extraterrestrials .

40 years ago, in 1977, the US Space and Aeronautics Agency (NASA) launched two Voyager spacecraft 1 and 2 carrying the message of the Earth people in the hope of successfully sending to the exoplanet ( if exist) in the distant universe.

Both spacecraft have a gold disk - the " alien" sent by aliens, with 116 images depicting life on planet Earth in the Solar System, including recording welcome in more than 50 different languages, the music, the natural sound of the Earth wished for a peaceful peace of the Earth .

Gold disk contains the message of the Earth people to send aliens.(Photo: NASA).

Up to now, both ships still travel extensively in the large space and continue to communicate with the Earth.

This is a testament to the effort of people not to be in contact with aliens.

Mankind did not find signs because .

However, planetary scientist of the Colorado Southwest Research Institute (USA) Alan Stern turned the issue over and cited why we didn't find aliens.

Speaking at the American Astronomical Society conference, Alan Stern points out:

"We all understand that our galaxy is vast, so there will be many mysterious galaxies that we cannot name yet.

In theory, having a planet with an ideal position with its star to form life (like Earth) is possible. So, why have we so far been unable to detect or at least capture the smallest signal even from "they" - People living outside the Earth?

If an extraterrestrial civilization exists beneath an icy ocean, Earth people will hardly find it, not to mention contacting them.

In fact, venturing to the planet's "surface" is also a difficult task. It is clear that just imagine having an extraterrestrial civilization hidden deep in the cold ice was too "difficult".

Mr. Alan Stern.(Artwork: Space.com).

Above is Alan Stern's view of why humans cannot find alien signs.

Once the universe also contains mysteries that people cannot fully understand, we still have the "right" to think of those that exist somewhere in the universe.

It is no coincidence that NASA, ESA . invested billions of dollars in the journey to pave the vastness out there.