Japan's Hayabusa2 is planning on "sneaking up" on an asteroid in order to land on it and collect data.

Hayabusa2 must 'sneak up' on asteroid for successful landing

Hayabusa2 must 'sneak up' on asteroid for successful landing

The asteroid sample-return mission was launched by Japanese space agency JAXA over three years ago in December 2014, and after arriving in orbit around asteroid Ryugu last month, it is now preparing for the tricky task of touching down on the fairly small near-Earth object.

According to Dante Lauretta - principle investigator for OSIRIS-Rex and member of the Hayabusa2 team - landing the spacecraft on Ryugu will difficult, and will require "sneaking up" on it whilst matching its speed.

He said: "You know the orbit of the asteroid, you know the orbit of the Earth, you know the rotation of the Earth, and then you can calculate exactly when you need to leave the surface of our planet to get onto that path.

"You've got to be formation-flying with the asteroid, so you kind of sneak up on it while moving in the same direction."

The most difficult part of the landing will be finding a "smooth surface" to land on, as Ryugu's surface has several boulders which could be difficult to touch down on.

Makoto Yoshikawa, Hayabusa2 mission manager, said: "I think the most difficult thing for touchdown is where to land. If you look at the image of Ryugu, you can find a lot of boulders on the surface. We must look for the smooth surface to touchdown. Maybe this is very difficult for this case."

Alongside Hayabusa2, the US launched OSIRIS-Rex, which is due to arrive on target at Bennu in August, and both agencies have already agreed to share any samples that are successfully returned to Earth.

Dante added to Wired UK: "In some ways we're each other's insurance policy. Each asteroid is its own unique world and worthy of exploration. Getting the samples from them will really help us piece together the geologic history of our solar system."