TOKYO » A Japanese space explorer was launched Wednesday on a six-year roundtrip journey to blow a crater in a remote asteroid and collect samples from inside in hopes of gathering clues to the origin of earth.

The explorer is expected to reach the asteroid in 2018 and spend about 18 months studying it before returning in 2020.

Hayabusa2, a rectangular unit with two sets of solar panels sticking out of its sides, was launched from Tanegashima Space Center in southern Japan. The main unit measures 3.2 x 5.2 x 4.6 feet and weighs about 1,300 pounds.

The research includes shooting a projectile into the asteroid to blast open a crater so the explorer can collect rock samples from inside.

Asteroids can provide evidence not available on earth about the birth of the solar system and its evolution. Japan’s space agency said Hayabusa2 will explore the origin of seawater and how the planet earth was formed.