Rina Noguchi

Rina Noguchi
Niigata University · Faculty of Science

Doctor of Philosophy
Working at Niigata University.

About

97
Publications
11,239
Reads
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1,890
Citations
Citations since 2016
65 Research Items
1747 Citations
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
20162017201820192020202120220100200300400500
Introduction
Rina Noguchi currently works at Faculty of Science, Niigata University. Rina does research in volcanology and planetary science. Their most recent publications are 'Radar sounding of subsurface structure in eastern Coprates and Capri Chasmata, Mars' and 'Crater depth-to-diameter ratios on asteroid 162173 Ryugu'. http://researchers.adm.niigata-u.ac.jp/html/200002461_en.html https://www.sc.niigata-u.ac.jp/sc/res/intro/NOGUCHIRina.html
Additional affiliations
April 2018 - March 2021
Japan Aerospace Exploration Agency
Position
  • PostDoc Position
April 2016 - March 2018
Tokyo Institute of Technology
Position
  • PostDoc Position
November 2015 - March 2016
National Institute of Advanced Industrial Science and Technology
Position
  • PostDoc Position
Education
April 2012 - July 2015
The University of Tokyo
Field of study
  • Earth and Planetary Science
April 2010 - March 2012
The University of Tokyo
Field of study
  • Earth and Planetary Science
April 2006 - March 2010
Tokai University
Field of study
  • Marine Mineral Resources

Publications

Publications (97)
Article
The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth's volatiles. Samples of Ryugu were retrieved by the Hayabusa2 spacecraft. We measure noble gas and nitrogen isotopes in Ryugu samples, finding they are dominated by pre-solar and primordial compo...
Article
The Hayabusa2 spacecraft returned to Earth from the asteroid 162173 Ryugu on December 6, 2020. One day after the recovery, the gas species retained in the sample container were extracted and measured on-site, and stored in gas collection bottles. The container gas consists of helium and neon with an extraterrestrial 3He/4He and 20Ne/22Ne ratios, al...
Article
Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed seventeen Ryugu samples measuring 1-8 mm. CO2-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that forme...
Article
Full-text available
Volatile and organic-rich C-type asteroids may have been one of the main sources of Earth’s water. Our best insight into their chemistry is currently provided by carbonaceous chondritic meteorites, but the meteorite record is biased: only the strongest types survive atmospheric entry and are then modified by interaction with the terrestrial environ...
Article
Full-text available
Abstract: Presented here are the observations and interpretations from a comprehensive analysis of 16 representative particles returned from the C-type asteroid Ryugu by the Hayabusa2 mission. On average Ryugu particles consist of 50% phyllosilicate matrix, 41% porosity and 9% minor phases, including organic matter. The abundances of 70 elements fr...
Article
Carbonaceous meteorites are thought to be fragments of C-type (carbonaceous) asteroids. Samples of the C-type asteroid (162173) Ryugu were retrieved by the Hayabusa2 spacecraft. We measure the mineralogy, bulk chemical and isotopic compositions of Ryugu samples. They are mainly composed of materials similar to carbonaceous chondrite meteorites, par...
Article
Full-text available
Hayabusa2 took on the challenge of collecting fresh subsurface samples from asteroid (162173) Ryugu during its second touchdown operation. For this ambitious goal, the spacecraft conducted artificial cratering by using a small carry-on impactor (SCI), leading to the exposure of subsurface materials. The key to mission success lies in the target sit...
Preprint
Full-text available
Asteroid 162173 Ryugu has numerous craters. The initial measurement of impact craters on Ryugu, by Sugita et al. (2019), is based on Hayabusa2 ONC images obtained during the first month after the arrival of Hayabusa2 in June 2018. Utilizing new images taken until February 2019, we constructed a global impact crater catalogue of Ryugu, which include...
Preprint
Full-text available
Asteroid 162173 Ryugu is a rubble-pile asteroid, whose top-shape is compatible with models of deformation by spin up. Rims of major craters on Ryugu have an east-west asymmetric profile; their western crater rims are sharp and tall, while their eastern crater rims are rounded and low. Although there are various possible explanations, we theoretical...
Article
Chryse and Acidalia Planitiae (CAP) are known as one of the areas which have abundant sites of recurring slope lineae (RSL) on Mars. We present a radar survey of shallow subsurface structures across the CAP regions using the Mars SHAllow RADar sounder (SHARAD) onboard the Mars Reconnaissance Orbiter (MRO). A total of 25 subsurface reflectors were i...
Article
Full-text available
Over a broad size range, the shapes of impact fragments from catastrophic disruptions are distributed around the mean axial ratio 2: √2: 1, irrespective of experimental conditions and target materials. Although most blocks on asteroids are likely to be impact fragments, there is not enough quantitative data for reliable statistics on their three-ax...
Article
The Hayabusa2 spacecraft investigated the C-type (carbonaceous) asteroid (162173) Ryugu. The mission performed two landing operations to collect samples of surface and sub-surface material, the latter exposed by an artificial impact. We present images of the second touchdown site, finding that ejecta from the impact crater was present at the sample...
Article
Full-text available
C-type asteroids ¹ are considered to be primitive small Solar System bodies enriched in water and organics, providing clues to the origin and evolution of the Solar System and the building blocks of life. C-type asteroid 162173 Ryugu has been characterized by remote sensing 2–7 and on-asteroid measurements 8,9 with Hayabusa2 (ref. ¹⁰ ). However, th...
Preprint
Full-text available
C-type asteroids likely formed in the outer Solar System and were then scattered inwards during giant planet migration (Walsh et al., 2011). They may have transported volatiles to the inner Solar System and created the conditions suitable for life on Earth(Alexander, 2017). Carbonaceous chondrites are fragments from C-type asteroids and provide evi...
Article
Full-text available
Planetesimals—the initial stage of the planetary formation process—are considered to be initially very porous aggregates of dusts1,2, and subsequent thermal and compaction processes reduce their porosity3. The Hayabusa2 spacecraft found that boulders on the surface of asteroid (162173) Ryugu have an average porosity of 30–50% (refs. 4–6), higher th...
Preprint
Full-text available
C-type asteroids are considered to be primitive small Solar-System bodies enriched in water and organics, providing clues for understanding the origin and evolution of the Solar System and the building blocks of life. C-type asteroid 162173 Ryugu has been characterized by remote sensing and on-asteroid measurements with Hayabusa2, but further studi...
Article
Full-text available
Analyses of meteorites and theoretical models indicate that some carbonaceous near-Earth asteroids may have been thermally altered due to radiative heating during close approaches to the Sun1–3. However, the lack of direct measurements on the subsurface doesn’t allow us to distinguish thermal alteration due to radiative heating from parent-body pro...
Article
Full-text available
Since phreatic eruptions often occur near the surface, it is important to understand the shallow subsurface structure of a volcano to clarify the eruption mechanism. The 2015 phreatic eruption at Owakudani, Hakone Volcano, Japan, was preceded by localized uplift and intensified steam activity. However, the cause of these events is unknown due to a...
Article
One of the primary goals of Hayabusa2 is to land on the asteroid Ryugu to collect its surface materials. The key for a successful touchdown is to find a promising landing site that meets both scientific and engineering requirements. Due to the limited availability of pre-arrival information about Ryugu, the landing site selection (LSS) must be cond...
Article
Full-text available
We surveyed the subsurface structure in eastern Coprates and Capri Chasmata in the equatorial region using high‐resolution visible images, digital terrain models, and radar sounding data. We identified subsurface reflectors in four areas of the chasmata. At the stratigraphic exposure on the chasmata walls, the corresponding depth of the reflector i...
Article
The near-Earth asteroid 162,173 Ryugu, the target of the Hayabusa2 mission, is noted to be a spinning top-shaped rubble-pile. Craters are among the most prominent surface features on Ryugu. Their shapes, particularly their depth-to-diameter ratio (d/D), can provide an important proxy for probing both the internal structure and surface processes of...
Article
Asteroid 162,173 Ryugu is a rubble-pile asteroid, whose top-shape is compatible with models of deformation by spin up. Rims of major craters on Ryugu have an east–west asymmetric profile; their western crater rims are sharp and tall, while their eastern crater rims are rounded and low. Although there are various possible explanations, we theoretica...
Article
Collecting a sample of asteroid Ryugu The Hayabusa2 spacecraft recently traveled to the nearby carbonaceous asteroid Ryugu to collect samples and return them to Earth for laboratory analysis. Morota et al. describe Hayabusa2's first sample collection, taken during a brief touchdown on Ryugu's surface. Close-up images and video taken during the samp...
Article
TIR, the thermal infrared imager on Hayabusa2, acquired high-resolution thermal images of the asteroid 162173 Ryugu for one asteroid rotation period on August 1, 2018 to investigate the thermophysical properties of the asteroid. The surface temperatures of Ryugu suggest that the surface has a low thermal inertia, indicating the presence of porous m...
Article
Blowing a crater in asteroid Ryugu The Hayabusa2 spacecraft was designed to collect samples from the nearby asteroid (162173) Ryugu and return them to Earth for laboratory analysis. Arakawa et al. describe how the spacecraft's Small Carry-on Impactor was fired into the asteroid's surface, producing an artificial impact crater. Analysis of the resul...
Article
Full-text available
Carbonaceous (C-type) asteroids¹ are relics of the early Solar System that have preserved primitive materials since their formation approximately 4.6 billion years ago. They are probably analogues of carbonaceous chondrites2,3 and are essential for understanding planetary formation processes. However, their physical properties remain poorly known b...
Article
Asteroid 162173 Ryugu has numerous craters. The initial measurement of impact craters on Ryugu, by Sugita et al. (2019), is based on Hayabusa2 ONC images obtained during the first month after the arrival of Hayabusa2 in June 2018. Utilizing new images taken until February 2019, we constructed a global impact crater catalogue of Ryugu, which include...
Preprint
Seasonal cycle of Martian relative humidity shows that, in the southern and the northern RSL sites, humidity decreases when RSL increment while humidity is high on the fading season. We suggest that the recurrence of RSL is caused by the different angle of response between wet and dry grains. 2D DEM simulation indicates that, when the ratio of a li...
Preprint
Full-text available
Seasonal cycle of Martian relative humidity shows that, in the southern and the northern RSL sites, humidity decreases when RSL increment while humidity is high on the fading season. We suggest that the recurrence of RSL is caused by the different angle of response between wet and dry grains. 2D DEM simulation indicates that, when the ratio of a li...
Article
Crustal deformation is essential information for monitoring volcanic activity. In the summit area of the Kusatsu-Shirane Volcano (KSV), a dense Global Navigation Satellite System (GNSS) network has been operating near the recent volcanic center, Yugama crater. This network is sensitive to shallow depth activity, such as phreatic eruptions at the su...
Conference Paper
Hayabusa2 is an asteroid sample return mission by Japan Aerospace Exploration Agency. It arrived at the C-type target asteroid Ryugu (162173) on 27 June 2018 and started proximity operation. One of the most difficult issues in asteroid exploration is a long time delay due to the distance between the asteroid and Earth. In order to achieve precise l...
Conference Paper
Full-text available
Recent planetary missions have revealed that sub-kilometer asteroids, such as Ryugu, Bennu, and Itokawa, are covered with many large boulders. Accurate measurements of the three-dimensional shapes of boulders on these asteroids are important for understanding their formation process and geologic evolution, and also to locate safe landing sites. In...
Conference Paper
Natural volcanic ash is formed in several states of magma (i.e., solid or melt) and surrounding conditions (e.g., dry or wet settings). These various factors affect the morphology of ash grain. For example, in a wet setting, moss-like grains are often formed (e.g., Wohletz, 1983). Thus, grain shape of volcanic ash tells us its fragmentation process...
Article
Full-text available
In 2018, the Japanese spacecraft Hayabusa2, arrived at the small asteroid Ryugu. The surface of this C-type asteroid is covered with numerous boulders whose size and shape distributions are investigated in this study. Using a few hundred Optical Navigation Camera (ONC) images with a pixel scale of approximately 0.65 m, we focus on boulders greater...
Article
The near-Earth carbonaceous asteroid 162173 Ryugu is thought to have been produced from a parent body that contained water ice and organic molecules. The Hayabusa2 spacecraft has obtained global multi-color images of Ryugu. Geomorphological features present include a circum-equatorial ridge, east/west dichotomy, high boulder abundances across the e...
Article
Full-text available
Hayabusa2 at the asteroid Ryugu Asteroids fall to Earth in the form of meteorites, but these provide little information about their origins. The Japanese mission Hayabusa2 is designed to collect samples directly from the surface of an asteroid and return them to Earth for laboratory analysis. Three papers in this issue describe the Hayabusa2 team's...
Conference Paper
The exploration of volcanoes across the solar system will deepen our understanding of volcanoes which are currently based on terrestrial studies. This study focuses on lava flows in Central Elysium Planitia which is one of the youngest volcanic fields on Mars. Using an ultra-high resolution digital terrain model, I describe the emplacement history...
Article
Full-text available
Rootless eruption is caused by lava flow entering inland water or wet sediment and forms craters and cones far from the actual vent. Since the rootless eruption can be significantly explosive, the possibility of rootless eruption is critical for hazard management; however, forecasting occurrence and explosiveness of a rootless eruption remains diff...
Article
Full-text available
Analyses of volcanic ash are typically performed either by qualitatively classifying ash particles by eye or by quantitatively parameterizing its shape and texture. While complex shapes can be classified through qualitative analyses, the results are subjective due to the difficulty of categorizing complex shapes into a single class. Although quanti...
Article
Full-text available
We developed a method to classify volcanic ash samples by introducing statistically determined grain types. Using more than 10,000 numbers of automatically measured grain data (parameters of grain shape and transparency) and the cluster analysis, we made grain types without human eyes. By components of the grain type in each samples, we classified...
Conference Paper
Full-text available
Rootless cone is one of peculiar types of pyroclastic cones, which is formed by magma-water interaction when hot lavas flow into waterlogged regions. Though the occurrence on the Earth is quite limited large numbers of small cones on Mars are suspected to be rootless cones. Identification of rootless cone is crucially important in the characterizat...
Conference Paper
Volcanic pyroclastic cones are one of the most common volcanic morphology in the solar system. They are constructed as a result of deposition of pyroclasts which are ejected from a stable vent. Their smaller and simpler edifices are useful to understand rock fragmentation and transportation mechanism. In planetary science, they are expected to be a...
Article
Full-text available
Shape analyses of tephra grains result in understanding eruption mechanism of volcanoes. However, we have to define and select parameter set such as convexity for the precise discrimination of tephra grains. Selection of the best parameter set for the recognition of tephra shapes is complicated. Actually, many shape parameters have been suggested....
Conference Paper
Rootless cones (RCs) are classified into a peculiar type of pyroclastic cones formed by lava-water interaction (Thordarson and Hoskuldsson, 2002). Different from other cone-forming eruptions the size is generally small so that they can be used as a miniature of volcanic eruptions which unite between large scale natural eruptions and laboratory scal...
Conference Paper
Rootless cones are a type of volcanic pyroclastic cones formed through lava-water interaction. When hot lava flows onto a region of waterlogged sediments secondary explosion is induced triggered by intense vesiculation of water and forms a pyroclastic cone. They are peculiar in that they are formed at remote places from lava emanation site. On Mars...
Conference Paper
Our motivations for this study are: 1) classify volcanic ash using statistical techniques, and 2) identify eruption styles from parameterized grain shape of pyroclasts. One of the extractable factors which we can infer eruption styles and mechanisms is grain morphology of ejected pyroclasts. They would tell us characteristics of magma vaporization...
Conference Paper
The rootless eruptions, which is a series of explosions by interactions of molten-lava and waterlogged sediments, have been focused in point of both the planetology and the volcanology (Fagents et al., 2002; Hamilton et al., 2010; 2017). On the surface of Mars, thousands of cones formed by rootless eruptions (e.g., Greeley and Fagents, 2001) are fo...
Article
Unique types of rootless cones have been found both on Earth and on Mars. They have inner cones inside their summit craters, and we call them double cones (DCs) and multiple cones. Though previous studies have mentioned their existence, there are no quantitative data on their topography, distribution, or constituent materials. Having this informati...
Article
Full-text available
Cone morphologies with a variety of origins and sizes have been widely identified on Mars using remote sensing data such as ultra-high resolution visible images. Currently, small cones of less than 100 m in bottom diameter can be identified. These Martian cones are located in young surface regions, suggesting they were produced in an environment th...
Conference Paper
Rootless cones (RC) have not been paid much attention so far because of their limited locations and their small size. They are formed by repeated phreatovolcanic explosions by lava-waterlogged sediments interactions. While the distribution is limited on the Earth, they have been pervasively recognized on Mars (e.g., Greeley and Fagents, 2001) and c...