.png){kind=icon}
返回
All Comets are Somewhat Hyperactive and the Implications Thereof
.png){kind=icon}
OA
AI
DOI：10.3847/PSJ/abf11f.png)
.png){kind=icon}
原文求助.png){kind=icon}
分享.png){kind=icon}
收藏
摘要
En 中文
We critically examine what hyperactivity on a comet entails, fully develop the A'Hearn Model for Hyperactivity based on the analyses of data collected for the Deep Impact encounter of comet 103P/Hartley 2, describe manifestations of hyperactivity suggested on many, if not all, comets, and give implications of hyperactivity for future cometary exploration. The A'Hearn model requires a highly volatile ice reservoir within a comet to undergo sublimation, escape the nucleus, and drive out less volatile ices along its path to the surface. Once in the coma, the less volatile ice eventually sublimates, creating a secondary source of that gas in the coma, which is generally displaced anti-sunward and not distributed symmetrically about the nucleus. The secondary source of gas increases the total production of the less volatile species in the coma, sometimes well above that expected if the total surface was undergoing sublimation. We argue that based on the simple assumptions of the A'Hearn model and the fact that several comets display one or more of the characteristics of hyperactivity detailed here, it is probable that nearly all comets experience some degree of hyperactivity. Of significance, the ice that is brought from deep within the nucleus into the coma via the process described by the A'Hearn model is the least thermally altered and is thus the most pristine ice in the comet. Therefore, it behooves future mission teams to consider cryogenically sampling coma ice, rather than or in addition to attempting a direct nucleus sample, for a better understanding of the unaltered ices and conditions present in the protoplanetary disk.
Keyword:
NARROW-BAND PHOTOMETRY
C/2009 P1 GARRADD
WATER ICE
103P/HARTLEY 2
HALE-BOPP
NUCLEUS
SURFACE
EPOXI
DUST
46P/WIRTANEN
期刊
IF:
4.3
论文数:
1.3K
被引数:
3.8K
机构
引用论文
Distinct contributions of the thin and thick filaments to length-dependent activation in heart muscle.png)
eLife
OAAI
eLifeIF0
OAAI分享收藏Regional surface morphology of comet 67P/Churyumov-Gerasimenko from Rosetta/OSIRIS images来自Rosetta/OSIRIS图像的彗星67p/churyumov-gerasimenko的区域表面形态OAAI
OAAI分享收藏UNCORRELATED VOLATILE BEHAVIOR DURING THE 2011 APPARITION OF COMET C/2009 P1 GARRADDASTRONOMICAL JOURNALOAAI
ASTRONOMICAL JOURNALIF5.1
OAAI分享收藏
查看更多内容