A grey image showing rocks and boulders on the asteroid's surface.

This image was taken from just one kilometre above the asteroid's surface. Image:  JAXA, Tokyo University, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji Univ., Aizu Univ., AIST.

Read later

Beta

During Beta testing articles may only be saved for seven days.

Close-up images of asteroid Ryugu captured by spacecraft Hayabusa2

The grey images were taken from a kilometre above the asteroid's surface, and they show craters, dust and boulders scattered across it.

The spacecraft Hayabusa2 has taken nearly four years to reach Ryugu from Earth. It's on a sample-return mission operated by the Japan Aerospace Exploration Agency (JAXA).

Several images have already been taken since it arrived at the asteroid six weeks ago, but these images provide the best view so far.

The craft will now spend 18 months observing the asteroid and collecting samples, before turning back for the long journey to Earth. Hayabusa2 will fly alongside the asteroid, map its surface, and deploy a lander to collect rocks and soils.

It is hoped that these observations will help experts to understand more about what asteroids are made of, and how the solar system formed.

Hayabusa2 descended towards the asteroid and took images at an altitude of 851 metres at about 8:10 on 7 August. Image: JAXA, Tokyo University.

 

Scientists at the Museum have been monitoring the Hayabusa2's progress carefully since it left Earth in December 2014.

Dr Ashley King, a planetary scientist, is interested in the use of a Near-Infrared Spectrometer (NIRS3) aboard the Hayabusa spacecraft.

The NIRS3 will examine sunlight reflected off the surface of the asteroid, and collect data about its colours and brightness. This data can then be compared to similar data from meteorites on Earth, giving us clues about the minerals on Ryugu.

Ashley says, 'Our first sight of Ryugu was exciting because we started to see the shape of the asteroid. It's taking new pictures every day and it is fascinating to monitor the mission's progress.

'I was in Japan in 2014 when the craft launched so this is really exciting.'

Ryugu is one of 18,000 near-Earth asteroids, which means its orbit could bring it close to Earth.

Measuring about one kilometre in diameter, the asteroid is not one solid mass, but essentially space rubble that has been stuck together by gravity.

Finding out more about the composition of that rubble could be the key to unlocking knowledge about existing meteorite collections.

There are plenty of rocks in Museum collections and universities that have broken off from asteroids and entered Earth's atmosphere. Once a rock touches the Earth's surface after coming through the atmosphere, it is called a meteorite.

Scientists are studying these rocks to learn more about the solar system - but there is a lot that they still have left to understand.

Sometimes, this is because it is difficult to know where a meteorite originated, and how long it has been on Earth for.

Prof Sara Russell, a Museum researcher, will be one of the first people to examine the samples that the Haybusa2 mission brings back to Earth. She is expected to travel to Japan when the spacecraft lands to analyse samples.

Sara says, 'The great thing about sample return missions is that we know anything brought back to Earth is pristine and hasn't been contaminated.

'At the moment, the way we learn about these asteroids is through studying meteorites that land on Earth. But these are often found years after they land, and have been altered by their entry into the atmosphere, or by years spent sat on the Earth's surface.

'With the samples that Hayabusa2 brings back, we also know exactly where on the asteroid the rocks have come from, which will help us to learn more about the specimens we already have.'

Once experts know more about the chemical makeup of Ryugu, they can compare the samples to meteorites in collection like the one held at the Museum.

Sara says, 'The data will help us to pair our meteorites to their asteroid parents, which will help us to understand the architecture of the solar system.'