Energetic proton irradiation history of the howardite parent body regolith and implications for ancient solar activity

AbstractThe Pioneer Venus and Venus Express missions, and the Mars Express and MAVEN missions, along with numerous Earth orbiters carrying space physics and aeronomy instruments, have utilized the increasing availability of space weather observations to provide better insight into the impacts of present-day solar activity on the atmospheres of terrestrial planets. Of most interest among these are the responses leading to escape of either ion or neutral constituents, potentially altering both the total atmospheric reservoirs and their composition. While debates continue regarding the role(s) of a planetary magnetic field in either decreasing or increasing these escape rates, observations have shown that enhancements can occur in both situations in response to solar activity-related changes. These generally involve increased energy inputs to the upper atmospheres, increases in ion production, and/or increases in escape channels, e.g. via interplanetary field penetration or planetary field ‘opening’. Problems arise when extrapolations of former loss rates are needed. While it is probably safe to suggest lower limits based simply on planet age multiplied by currently measured ion and neutral escape rates, the evolution of the Sun, including its activity, must be folded into these estimations. Poor knowledge of the history of solar activity, especially in terms of coronal mass ejections and solar wind properties, greatly compounds the uncertainties in related planetary atmosphere evolution calculations. Prospects for constraining their influences will depend on our ability to do a better job of solar activity history reconstruction.

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Some patterns in the development of centers of solar activity, 1962–66

Symposium - International Astronomical Union ◽

10.1017/s0074180900021318 ◽

1968 ◽

Vol 35 ◽

pp. 56-63 ◽

Cited By ~ 6

Author(s):

Helen W. Dodson ◽

E. Ruth Hedeman

Keyword(s):

Solar Activity ◽

Radio Emission ◽

Differential Rotation ◽

Graphical Representation ◽

Past History ◽

The Sun ◽

Active Centers ◽

Opposite Hemisphere ◽

The Past ◽

History Of

A graphical representation of the 66 solar rotations (Carrington) between January 1, 1962 and December 31, 1966 has been prepared. It includes all centers of activity for which the calcium plage attained an area of at least 1000 millionths of the solar hemisphere and/or intensity 3 (McMath scale). In this study the antecedents, descendents, and neighbors of each region can easily be discerned. The work shows clearly that zones of activity, apparently closely related and much larger than single plages existed for long intervals of time. For example, the significant increases in solar activity in February, May, and October of 1965 occurred in a ‘family’ of calcium plages apparently related through similarities of position and strong radio emission.The members of ‘families’ of centers of activity are found at systematically changing longitudes. For some ‘families’ the change of longitude appears to be primarily a consequence of differential rotation; for others, the pattern of formation of active centers dominates.According to the data for 1962–66 a meaningful study of the development of a center of activity may require consideration not only of the past history of the zone of the Sun in which it occurs but also of the zone approximately 180° away on the opposite hemisphere.

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Properties of Ices and Grains: An experimental study

Highlights of Astronomy ◽

10.1017/s1539299600005335 ◽

1983 ◽

Vol 6 ◽

pp. 347-354

Author(s):

Bertram Dorm

Keyword(s):

Low Temperatures ◽

Proton Irradiation ◽

Cosmic Ray ◽

Oort Cloud ◽

The Sun ◽

Organic Residue ◽

History Of ◽

Composition Structure ◽

Galactic Cosmic Ray ◽

Complex Organic

AbstractProton irradiation of a variety of ice mixtures were carried out to study the effect of galactic cosmic ray irradiation of comets in the Oort Cloud. Three significant effects were noted (1) production of new molecules; (2) production of a more energetic ice at low temperatures; (3) production of a non-volatile, complex organic residue. These phenomena suggest various effects on new comets approaching the sun including enhanced activity. Experiments on the condensation of silicate grains provide information on the condensation mechanism and properties of grains. Controlled annealing of the amorphous condensates shows how crystallization occurs. Infrared spectra of different stages of crystallization contain features that may identify composition, structure and history of refractory material.

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Hf–W thermochronometry: Closure temperature and constraints on the accretion and cooling history of the H chondrite parent body

Earth and Planetary Science Letters ◽

10.1016/j.epsl.2008.03.013 ◽

2008 ◽

Vol 270 (1-2) ◽

pp. 106-118 ◽

Cited By ~ 102

Author(s):

Thorsten Kleine ◽

Mathieu Touboul ◽

James A. Van Orman ◽

Bernard Bourdon ◽

Colin Maden ◽

...

Keyword(s):

Parent Body ◽

Closure Temperature ◽

Cooling History ◽

History Of

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Chondrules in CK carbonaceous chondrites and thermal history of the CV-CK parent body

Meteoritics and Planetary Science ◽

10.1111/maps.12599 ◽

2016 ◽

Vol 51 (3) ◽

pp. 547-573 ◽

Cited By ~ 13

Author(s):

Noël Chaumard ◽

Bertrand Devouard

Keyword(s):

Thermal History ◽

Parent Body ◽

Carbonaceous Chondrites ◽

History Of

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The Polymict Eucrites Elephant Moraine A79004 and A79011 and the regolith history of a basaltic achondrite parent body

Journal of Geophysical Research Atmospheres ◽

10.1029/jb087is01p0a339 ◽

1982 ◽

Vol 87 (S01) ◽

pp. A339 ◽

Cited By ~ 5

Author(s):

Jeremy S. Delaney ◽

M. Prinz ◽

C. E. Nehru ◽

C. O'Neill

Keyword(s):

Parent Body ◽

History Of ◽

Basaltic Achondrite

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Constitution of terrestrial planets

Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences ◽

10.1098/rsta.1981.0203 ◽

1981 ◽

Vol 303 (1477) ◽

pp. 287-302 ◽

Cited By ~ 282

Keyword(s):

Bulk Composition ◽

Parent Body ◽

The Moon ◽

Volatile Elements ◽

Earth’S Mantle ◽

The Earth ◽

History Of ◽

Relationship Of ◽

Reduced State

Reliable estimates of the bulk composition are so far restricted to the three planetary objects from which we have samples for laboratory investigation, i.e. the Earth, the Moon and the eucrite parent asteroid. The last, the parent body of the eucrite— diogenite family of meteorites, an object that like Earth and Moon underwent magmatic differentiations, seems to have an almost chondritic composition except for a considerable depletion of all moderately volatile (Na, K, Rb, F, etc.) and highly volatile (Cl, Br, Cd, Pb, etc.) elements. The Moon is also depleted in moderately volatile and volatile elements compared to carbonaceous chondrites of type 1 (Cl) and also compared to the Earth. Again normalized to Cl and Si the Earth’s mantle and the Moon are slightly enriched in refractory lithophile elements and in magnesium. It might be that this enrichment is fictitious and only due to the normalization to Si and that both Earth’s mantle and Moon are depleted in Si, which partly entered the Earth’s core in metallic form. The striking depletion of the Earth’s mantle for the elements V, Cr and Mn can also be explained by their partial removal into the core. The similar abundances of V, Cr and Mn in the Moon and in the Earth’s mantle indicate the strong genetic relationship of Earth and Moon. Apart from their contents of metallic iron, all siderophile elements, moderately volatile and volatile elements, Earth and Moon are chemically very similar. It might well be that, with these exceptions and that of a varying degree of oxidation, all the inner planets have a similar chemistry. The chemical composition of the Earth’s mantle, for which reliable and accurate data have recently been obtained from the study of ultramafic nodules, yields important information about the accretion history of the Earth and that of the inner planets. It seems that accretion started with highly reduced material, with all Fe as metal and even Si and Cr, V and Mn partly in reduced state, followed by the accretion of more and more oxidized matter.

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