JAXA：在“Ryugu”上发现新岩石：“Hayabusa2”
-太阳系进化论膨胀的妄想-
日本宇宙航空研究开发机构：
我们在小行星“龙宫”上发现了一块几乎没有变化的岩石。
这块岩石保留了“龙宫小行星母体形成的早期状态”。
“隼鸟2”：
小行星探测器“隼鸟2号”下降时拍摄的图像分析。
事实证明，“岩石轻到可以漂浮在水面上，而且密度很低。”
Hayabusa2收集的样本中也可能包含该成分。
这将导致龙宫的起源以及太阳系中行星形成和演化的发展。
与立教大学共同研究：
结果于5月25日发表在英文科学期刊《自然天文学》上。
龙宫上的火山口：
请注意龙宫上两个直径小于等于 20 米的陨石坑。
在火山口的中心，白天的温度高于周围环境。
原来，“有一团10厘米的黑色岩石”。
这个地方有很强的隔热性
白天容易热身
它的特点是晚上容易变冷。
龙宫岩：
到目前为止，龙宫岩的孔隙度被认为是 30-40%。
然而，他发现他发现的岩石是“一种孔隙率高达 70% 的轻质物质”。
洛克这次发现：
人们认为“保留了母天体表层的状态”。
很可能是龙宫的母体形成的带有早期信息的物质。
新开关
Anomalously porous boulders on (162173) Ryugu as primordial materials from its parent body
Abstract
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. 4,5,6), higher than meteorites but lower than cometary nuclei7, which are considered to be remnants of the original planetesimals8.
Here, using high-resolution thermal and optical imaging of Ryugu’s surface,
we discovered, on the floor of fresh small craters (<20 m in diameter), boulders with reflectance (~0.015) lower than the Ryugu average6 and porosity >70%, which is as high as in cometary bodies.
The artificial crater formed by Hayabusa2’s impact experiment9 is similar to these craters in size but does not have such high-porosity boulders.
Thus,
we argue that the observed high porosity is intrinsic and not created by subsequent impact comminution and/or cracking.We propose that these boulders are the least processed material on Ryugu and represent remnants of porous planetesimals that did not undergo a high degree of heating and compaction3.
Our multi-instrumental analysis
suggests that fragments of the highly porous boulders are mixed within the surface regolith globally, implying that they might be captured within collected samples by touch-down operations10,11.
Nature Astronomy
https://www.nature.com/articles/s41550-021-01371-7