月惑星科学会議(LPSC):「はやぶさ2」 と小惑星リュウグウ

Google 翻訳: アブストラクト: 日本惑星協会によるセッションレポート(日本語):
Junya Terazono 寺薗淳也 @terakinizers

さて、ここから日本語と英語同時につぶやけるだろうか? 一応英語優先になるのでご了承を。 #Hayabusa2 #はやぶさ2 #LPSC2019

2019-03-20 03:29:41
Junya Terazono 寺薗淳也 @terakinizers

High Porosity Nature of the Top-Shaped C-Type Asteroid #Ryugu (Seiichiro Watanabe): He is a Science Manager of #Hayabusa2 . Special Coverage of #Science is out today. Lectures based on these papers. #LPSC2019

2019-03-20 03:34:05
Junya Terazono 寺薗淳也 @terakinizers

本日、#はやぶさ2 について特集した「サイエンス」が刊行されたとのこと。従って、その話を #LPSC2019 にてはじめて披露することにある。

2019-03-20 03:35:17
Junya Terazono 寺薗淳也 @terakinizers

誠一郎さんの講演はこれまでの #はやぶさ2 のミッションを振り返る形で進んでいる。 #LPSC2019

2019-03-20 03:36:54
Junya Terazono 寺薗淳也 @terakinizers

Shape of #Ryugu reconstructed by two methods, two Universities (Kobe and AIzu, my Univ). #LPSC2019

2019-03-20 03:37:38
Junya Terazono 寺薗淳也 @terakinizers

#Ryugu obliquity 172 deg (retrospinning), bulk density: 1.19, exactly same as #Bennu . Total porosity > 50%. Seemingly rubble-pile asteroid. Abundant boulders, number density is twice as Itokawa. #LPSC2019

2019-03-20 03:39:14
Junya Terazono 寺薗淳也 @terakinizers

NIRS3 found global 2.7 μm absorption (10%), showing existence of water. #LPSC2019

2019-03-20 03:40:50
Junya Terazono 寺薗淳也 @terakinizers

Using derived density and shape model, they calculated surface slope calculation, and found that rotation was faster in older time to explain distribution of slopes. (3.5h). #LPSC2019

2019-03-20 03:42:18
Junya Terazono 寺薗淳也 @terakinizers

Formation scenario of the top shape of #Ryugu: landslides or interior failure ? #LPSC2019

2019-03-20 03:43:53
Junya Terazono 寺薗淳也 @terakinizers

First touchdown site of #Hayabusa2 was named as "Tamatebako", a treasure box in Japanese old tale "Urashima Taro" which is the base of the name #Ryugu . #LPSC2019

2019-03-20 03:45:35
Junya Terazono 寺薗淳也 @terakinizers

#ryugu 's top shape was formed by a rotation-induced structural failure. #LPSC2019

2019-03-20 03:46:43
Junya Terazono 寺薗淳也 @terakinizers

The Evolution of #Ryugu 's Parent Body (Seiji Sugita, Camera PI): Ryugu is probably from inner main belt, and C-Complex families are limited in inner belt. #LPSC2019

2019-03-20 03:49:27
Junya Terazono 寺薗淳也 @terakinizers

#Ryugu 's very flat spectra is consistent with Cb, Eularlia and Polana are candidates for Ryugu's parent body, and thermally metamorphosed. #LPSC2019 #Hayabusa2

2019-03-20 03:50:56
Junya Terazono 寺薗淳也 @terakinizers

非常に印象的なのは、オシリス・レックスのチームが割と普段着で発表していたのに対し、 #はやぶさ2 チームは背広にネクタイでびしっと決めて発表しているということ。この会場でネクタイを締めているというのはかなり珍しい。 #LPSC2019

2019-03-20 03:52:06
Junya Terazono 寺薗淳也 @terakinizers

According to crater analysis, the surface of #Ryugu is young, <1 million yrs. Thermal deyhdration due to solar heating is unlikely. #LPSC2019

2019-03-20 03:53:20
Junya Terazono 寺薗淳也 @terakinizers

No regolith with strong 0.7 μm absorption. It suggest subsurface layer is probably depleted in hydrated minerals. #LPSC2019

2019-03-20 03:54:11
Junya Terazono 寺薗淳也 @terakinizers

There are four type of boulders in #Ryugu . Type 1: Dark and Rugged, Type 2: smooth and bright, Type 3: bright and mottled, Type 4: Otohime ... special one in spectral feature. #Hayabusa2 #LPSC2019

2019-03-20 03:55:56
Junya Terazono 寺薗淳也 @terakinizers

Textures: Layered structures and possible impact breccia. Evidence for fragmentation, mixing and sedimentation of parent body. #Hayabusa2 #LPSC2019

2019-03-20 03:59:01
Junya Terazono 寺薗淳也 @terakinizers

Scenario of Ryugu: Aqueous Alteration -> Internal heating maybe due to 26AI and Dehydration -> Impact -> ... #LPSC2019 #Hayabusa2

2019-03-20 04:00:07
Junya Terazono 寺薗淳也 @terakinizers

#Ryugu as seen by MASCOT Camera (Schroeder): Due to request from presenter, I will reflain from tweeting on this presentation. #LPSC2019 #Hayabusa2

2019-03-20 04:03:18
Junya Terazono 寺薗淳也 @terakinizers

#リュウグウ の起源についてだが、もともと水和物に富む母天体があり、それが熱変性(おそらく放射性アルミの崩壊熱)によって脱水を起こし、それが壊れたあと再集積した(このあたり私は聞き取れなかった)ものと考えられる。#はやぶさ2 #LPSC2019

2019-03-20 04:10:37
Junya Terazono 寺薗淳也 @terakinizers

しかし、#リュウグウ の密度までベンヌと全く同じなんて、なんということだろう… #はやぶさ2 #LPSC2019

2019-03-20 04:12:35
Moon Maven Emily Lakdawalla @elakdawalla

Schroeder: Has fabulous MASCOT images, fascinating comparison of daytime and nighttime (LED-illuminated) images. In night images, can see "inclusions' in rocks. Millimeter scale -- might these be chondrules? #LPSC2019

2019-03-20 04:16:03