TOKYO — Japanese space explorer Hayabusa2 on Wednesday reached its destination near a small asteroid named Ryugu about 300 million kilometers from Earth, after a more than three-year journey on a mission that may elucidate the origin of life.

After traveling 3.2 billion kilometers, Hayabusa2 now hovers about 20 km above the asteroid, Japan’s space agency said.

The explorer will stay close to Ryugu for the next 18 months as it conducts research which could provide new insights into the evolution of the solar system and the origin of life, according to the Japan Aerospace Exploration Agency.

Yuichi Tsuda, an associate professor at JAXA and the manager of the Hayabusa2 project, told a press conference at the agency’s space institute in Sagamihara near Tokyo that the achievement can be regarded as “setting foot at the entrance of space science research where no man has gone before.”

“We will explore a new world which no one has seen before,” Tsuda said, adding he would like to produce an outcome surpassing that of the original Hayabusa asteroid probe, which collected the first ever samples from an asteroid in space.

He also said Hayabusa2 remains “in very good condition.”

“More than anything, I am relieved,” said Makoto Yoshikawa, the mission manager. Saying “it was good that we have chosen Ryugu (for the target)”, Yoshikawa said “my instinct tells me that we will see a significant achievement.”

After confirming the arrival of the probe Wednesday morning, applause broke out in the operations room at the JAXA space institute, according to Yoshikawa.

In a bid to collect rock samples, Hayabusa2 is scheduled to make three landings on the asteroid, named after an undersea dragon palace in a Japanese fairy tale, where the mythical fisherman Urashima Taro found a treasure box.

The spacecraft can drop a 2-kilogram copper lump, known as an impactor, to the surface of the asteroid to make an artificial crater and obtain “fresh” unexposed materials.

The probe’s first touchdown is expected in September or October. JAXA plans to pick a landing spot in late August by utilizing cameras and other equipment on the probe.

Initial observations indicate Ryugu has a rough surface strewn with numerous rocks and craters.

The small unmanned spacecraft, equipped with devices including cameras and sensors, will also monitor the asteroid and study its gravity, temperature and surface conditions.

It also has three tiny rovers, each of which is designed to roam the surface of Ryugu to conduct probes.

Diamond-shaped Ryugu, estimated to have a diameter of about 900 meters, travels around the Sun every 16 months, passing near the orbits of Earth and Mars.

Ryugu’s blackish color is believed to indicate the asteroid has abundant carbon, an important element for life.

Ryugu is also believed to contain water and other materials for life, unlike the asteroid Itokawa, which was probed by Hayabusa2’s predecessor.

Launched in December 2014 from the Tanegashima Space Center in southwestern Japan, the roughly 600-kg Hayabusa2 has had a trouble-free journey and adjusted its orbit from early June before reaching its destination, according to JAXA.

It is due to return to Earth at the end of 2020 with the rock samples.

JAXA launched the first Hayabusa, meaning peregrine falcon in Japanese, in 2003 and the explorer returned to Earth in 2010.

But Hayabusa’s journey of 6 billion km to and from the asteroid Itokawa was plagued with technical glitches, including a total loss of communications at one point and engine failures.