A Japanese spacecraft arrives at the asteroid to study the surface

A Japanese spacecraft has arrived at a asteroid Wednesday after traveling for more than three years.

The Hayabusa2 spacecraft must perform a new experiment. This will create a crater on the surface of the asteroid by collecting pieces of rock to bring back to Earth.

The Japan Aerospace Exploration Agency (JAXA) said the Hayabusa2 is about 20 kilometers from the asteroid that orbited the sun 280 million kilometers from the Earth.

Over the next year and a half, the robotic explorer will attempt three short landings to collect rocks. If they succeed, the asteroid material could provide information on the beginning of the solar system and maybe life on Earth.

Space officials say, however, that mission will be difficult.

Hayabusa2 will spend about two months looking for safe landing places on the rough surface. Due to the high surface temperature, there will only be a few seconds each time it lands. All collected rock will be returned to a re-entry container expected to arrive at the end of 2020.

The asteroid is named Ryugu after a submarine palace in a Japanese folktale. Ryugu is about 900 meters wide.

In photographs published by JAXA, the Japanese space agency, the asteroid appears to be more square than round. A number of large craters can be seen. Project manager Yuichi Tsuda described the asteroid in an online article. He said that the rough surface would make the choice of landing places "both interesting and difficult".

The first landing is scheduled for September or October. The final landing is scheduled for April or May. Before the final landing, Hayabusa2 will send a device that will explode over the asteroid. He will shoot a two kilogram copper object into the asteroid at high speed to create a crater.

Hayabusa2 will reposition itself on the other side of the asteroid to protect itself during the operation.

It will take another two to three weeks to make sure that any wrecks that could damage the explorer have disappeared. Hayabusa2 will then attempt to land at or near the crater to collect underground or surface material that has been blown away by the explosion.

The spacecraft will also send three vehicles or probes. The probes do not have wheels but can jump around to study the surface and collect rocks. Hayabusa2 will also send a Franco-German undercarriage to study the surface with four observation devices.

Asteroids gravitate around the sun but are much smaller than the planets. They are among the oldest objects of the solar system. For this reason, scientists believe that they can help explain how the Earth has developed. They can even provide information on ocean formation and the beginning of life.

Hayabusa2 was launched from Japan in December 2014. It follows the first Hayabusa mission that lasted from 2003 to 2010.

The first spacecraft in the series collected rocks of another type of asteroid. Hayabusa took three years longer than expected after a series of technical problems.

The US space agency, NASA, also has an asteroid mission. His Osiris-Rex spacecraft is expected to reach the asteroid Bennu later this year and return with rocks in 2023.

I am Mario Ritter.

This story was originally reported by Ken Moritsugu for the Associated Press. Phil Dierking adapted this story for VOA Learning English. Mario Ritter was the editor.

Words in this story

asteroid -not. objects that are smaller than planets and are usually not perfectly round and revolve around the sun

crater -not. a bowl-shaped hole formed by a falling meteorite or volcanic explosion

folktale -not. a traditional story

palace -not. the official home of a person like a king, a queen or a president

solar system -not. all objects in orbit or influenced by the gravity of the sun

jump -v. jump up and down