NASA is taking a different approach to humanity's search for alien life by diving deep into the Earth's oceans.

Diving Deep To Find Life In Outer Space

Just 22 miles off the coast of Hawaii's Big Island is an underwater volcano belching out hot bubbles from beneath the seafloor. This is the Lo'ihi Seamount, an active volcano that scientists at NASA believe is very similar to the places on the solar system with the biggest potential to harbor life.

Deep beneath the surface of the ocean are hydrothermal vents. These are crevices on the seafloor from which geothermally heated water arises. Hydrothermal vents are often found near active volcanoes, tectonic plates, and hotspots. Scientists believe that the first signs of life on Earth emerged from hydrothermal vents.

The theory is the geothermal heat emitted by the fissures has caused chemical reactions on the sea floor that led to the growth of the first one-celled organisms.

Sunlight cannot penetrate deep into the places where hydrothermal vents are found. Therefore, creatures who live there rely on these chemical reactions for sustenance.

For example, the hydrogen sulfide released from the cracks on the sea floor reacts with the oxygen from the seawater to form sugar, which is then used up by microbes for food.

Is There Life On Jupiter and Saturn's Moons?

When Cassini discovered that Enceladus, the sixth largest moon surrounding Saturn, was spewing streams of hot water into the atmosphere, scientists began speculating about the origins of the hot water plumes.

Very possibly, there must be some sort of chemical reaction happening under the surface of Enceladus' massive ocean to cause such a phenomenon. Jupiter's Europa is also known to have a vast underwater world beneath its icy crust. Along with Enceladus, Europa is one of the most likely places in the solar system where life or signs of it could be found.

"Scientists think these moons are good places for potential life," says Abby Tabor, NASA public affairs officer, " because water interacting with rock on their sea floors could yield chemical reactions that would make microbial metabolism."

Scientists believe that hydrothermal vents can be found on the seafloor of Enceladus and Europa. By studying the environment of Lo'ihi Seamount, which NASA thinks is very similar to that of the two moons, they could possibly find clues as to the best possible way to find life in outer space.

NASA has explored other hydrothermal vents before, including the Von Damm Vent Field at 7,500 feet below the sea near the Caribbean islands and the Piccard Field at 16,000 feet deep in the Cayman Trough. However, these are located close to tectonic plates where temperatures are too hot to mimic that of Europa and Enceladus.

An Undersea Mission For Space

Called Systematic Underwater Biogeochemical Science and Exploration Analog, or SUBSEA, the mission aims to prepare NASA's scientists for exploring other worlds by diving into similar environments. The Lo'ihi Seamount is one such environment.

Geobiologist Darlene Lim, of NASA's Ames Research Center in Silicon Valley, will spearhead the mission, which will take place onboard the U.S.S. Nautilus. Two underwater robots, Hercules and Argus, will also be deployed.

The mission is set to launch in August 2018.