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Article
Open AccessParticle size distributions inside and around the artificial crater produced by the Hayabusa2 impact experiment on Ryugu
Japanese Hayabusa2 spacecraft has successfully carried out an impact experiment using a small carry-on impactor (SCI) on an asteroid (162173) Ryugu. We examine the size distribution of particles inside and out...
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Article
Anomalously porous boulders on (162173) Ryugu as primordial materials from its parent body
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 Ha...
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Article
Thermally altered subsurface material of asteroid (162173) Ryugu
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...
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Article
Collisional history of Ryugu’s parent body from bright surface boulders
The asteroid (162173) Ryugu and other rubble-pile asteroids are likely re-accumulated fragments of much larger parent bodies that were disrupted by impacts. However, the collisional and orbital pathways from t...
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Article
Stationary waves and slowly moving features in the night upper clouds of Venus
At the cloud top level of Venus (65–70 km altitude) the atmosphere rotates 60 times faster than the underlying surface—a phenomenon known as superrotation1,2. Whereas on Venus’s dayside the cloud top motions are ...
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Article
Open AccessOverview of Venus orbiter, Akatsuki
The Akatsuki spacecraft of Japan was launched on May 21, 2010. The spacecraft planned to enter a Venus-encircling near-equatorial orbit in December 7, 2010; however, the Venus orbit insertion maneuver has fail...
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Chapter and Conference Paper
Activity of Bacteriorhodopsin in the Presence of a Large pH Gradient
Bacteriorhodopsin (bR) is a membrane protein found in Halobacterium halobium. Due to the retinal chromophore bound to the apoprotein via a protonated Schiff base linkage, bR shows a strong absorpt...
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Chapter and Conference Paper
Structure Change of Bacteriorhodopsin and the Mechanism of Proton Pump
Bacteriorhodopsin(bR) is a transmembrane protein in the purple membrane of Ha1obacterium halobium. It pumps protons across the membrane using light energy absorbed by retinal in it. Although the mechanism of t...
