Asteroid Ryugu Likely Link in Planetary Formation

Formation scenario for Ryugu. More than one year ago, the Japanese Hayabusa2 orbiter deployed the German lander, MASCOT, which investigated the approximately one-kilometre-diameter asteroid Ryugu. Scientists are now imagining the history of its formation 4.5 billion years ago. First, flakes and grains of dust formed in the disc of dust and gas rotating around the Sun (1), before porous planetesimals agglomerated due to the accretion of these loose flakes (2). Recent investigations suggest that Ryugu’s parent body hardly condensed and was also highly porous. This may have resulted in the formation of a firmer core, but scientists also believe that a gradual increase in density towards the centre of the parent body is conceivable (3). Impacts and collisions with other asteroids (4) led to a fragmentation of the parent body; the large boulders on Ryugu probably originated here. Part of the debris was then the source material for the accretion of Ryugu (5), with porous blocks and loose material, and also some more compact blocks of higher density from the original core, some of which remain on the surface. Ryugu‘s present diamondlike shape (6) occurred over time due to its rotation. (Credit: Okada et al. Nature 2020)
  • Infrared images show that Ryugu is almost entirely made up.
  • The asteroid was formed largely from fragments of a parent body that was shattered by impacts of highly porous material.
  • DLR scientists participate in the publication in the scientific journal Nature.

COLOGNE, Germany (DLR PR) — The Solar System formed approximately 4.5 billion years ago. Numerous fragments that bear witness to this early era orbit the Sun as asteroids. Around three-quarters of these are carbon-rich C-type asteroids, such as 162173 Ryugu, which was the target of the Japanese Hayabusa2 mission in 2018 and 2019. The spacecraft is currently on its return flight to Earth.

Numerous scientists, including planetary researchers from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), intensively studied this cosmic ‘rubble pile’, which is almost one kilometre in diameter and can come close to Earth. Infrared images acquired by Hayabusa2 have now been published in the scientific journal Nature. They show that the asteroid consists almost entirely of highly porous material.


The Near-Earth Asteroid Ryugu – a Fragile Cosmic ‘Rubble Pile’

  • The asteroid is similar to carbonaceous, 4.5 billion year old meteorites found in collections on Earth.
  • Ryugu has numerous cavities.

COLOGNE, Germany (DLR PR) — In the summer of 2018, the asteroid Ryugu, which measures only approximately 850 metres across, was visited by the Japanese Hayabusa2 spacecraft. On board was the 10-kilogram German-French Mobile Asteroid Surface Scout (MASCOT) – a lander no bigger than a microwave oven and equipped with four instruments.


Hayabusa2’s MASCOT Lander Confirms What Scientists Have Long Suspected at Asteroid Ryugu

Close-up of the rock examined by MASCOT. The yellow arrow shows the direction of the incident light, and the dotted line separates the observed stone from the background. The red arrow shows the part of the rock where the radiometer MARA measured the surface temperature, the dotted line here shows a ledge. The scale in the center of the image shows the dimensions at this distance from the camera. The image was acquired by the DLR camera MASCAM on MASCOT. (Credit: MASCOT/DLR/JAXA)

COLOGNE, Germany (DLR) PR) — Ryugu and other asteroids of the common ‘C-class’ consist of more porous material than was previously thought. Small fragments of their material are therefore too fragile to survive entry into the atmosphere in the event of a collision with Earth.

This has revealed the long-suspected cause of the deficit of this meteorite type in finds on Earth. Researchers at the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) have come to this conclusion in a scientific paper published in the journal Nature Astronomy.


MASCOT Successfully Completes Exploration of Asteroid Ryugu

Figure 1c (Credit : JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST)

  • As planned, MASCOT was able to acquire data about the composition and texture of the asteroid at several locations.
  • Before the battery depleted, the lander sent all scientific data to the Hayabusa2 mothercraft.
  • New images from MASCOT’s landing on asteroid Ryugu were presented by DLR, JAXA and CNES today at the International Astronautical Congress (IAC).

COLOGNE, Germany (DLR PR) — It was a day full of exciting moments and a happy team of scientists and engineers: late in the afternoon of 3 October 2018, the German-French lander MASCOT completed its historic exploration of the surface of the asteroid Ryugu at 21:04 CEST, as its battery ran out.

On-asteroid operations were originally scheduled to last 16 hours after separation from the Japanese mothercraft Hayabusa2. But in the end, the battery lasted more than 17 hours.


A Closer Look at Hayabusa2’s MASCOT Asteroid Lander

Left: Illustration of MASCOT separating from Hayabusa2. Right: Illustration of MASCOT landing on the surface of Ryugu. (Credit: JAXA)

TOKYO (JAXA PR) — MASCOT (Mobile Asteroid Surface Scout) is the asteroid lander jointly developed by DLR (German Aerospace Center) and CNES (French National Center for Space Studies). MASCOT is stored on the -Y-plane side of Hayabusa2 (this is the left-hand side surface when the high gain antenna is at the head and the ion engine is at the spacecraft back) and deployed from this position (see Figure 1).

MASCOT Lands Safely on Asteroid Ryugu

Figure 3: Left: Illustration of MASCOT separating from Hayabusa2. Right: Illustration of MASCOT landing on the surface of Ryugu. (Credit: JAXA)

COLOGNE, Germany (DLR PR) — The near-Earth asteroid Ryugu, located approximately 300 million kilometres from Earth, has a new inhabitant: On 3 October 2018, the Mobile Asteroid Surface Scout (MASCOT) landed on the asteroid and began to work.

The lander successfully separated from the Japanese Hayabusa2 space probe at 03:58 CEST. The 16 hours in which the lander will conduct measurements on the asteroid’s surface have begun for the international team of engineers and scientists.

Landing on Ryugu – A Surface with a View of Boulders

The boulder-strewn surface of asteroid Ryugu. (Credit: JAXA, University of Tokyo, Kochi University, Rikkyo University, Nagoya University, Chiba Institute of Technology, Meiji University, University of Aizu, AIST.)

COLOGNE, Germany (DLR PR) — In early October 2018, the Mobile Asteroid Surface Scout (MASCOT) lander is expected to be in operation for approximately 16 hours on the Ryugu asteroid. The selection of the landing site will take place this August. The ideal site must firstly offer the MASCOT team engineers excellent conditions for a safe landing and stable operation on the asteroid, while providing the researchers with a wealth of new and productive measurements.


MASCOT’s Asteroid Landing – Preparations, Risks and Last-minute Decisions

Asteroid Ryugu photographed by Japan’s Hayabusa2 spacecraft. (Credit: JAXA)

COLOGNE, Germany (DLR PR) — Scientists and engineers have been waiting nearly four years for the Japanese Hayabusa2 spacecraft – which is carrying the Mobile Asteroid Surface Scout (MASCOT) lander that was developed and constructed by the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR) – to reach its destination: the asteroid Ryugu. With the approach and arrival having taken place on 27 June 2018, the landing is now within reach.