An estimation of the mass dragged by the solar wind from Mars’s atmosphere in its geologic history

Héctor Javier Durand-Manterola

doi:10.22201/igeof.00167169p.2001.40.4.415

An estimation of the mass dragged by the solar wind from Mars’s atmosphere in its geologic history

Geofísica Internacional ◽

10.22201/igeof.00167169p.2001.40.4.415 ◽

2001 ◽

Vol 40 (4) ◽

pp. 315-320

Author(s):

Héctor Javier Durand-Manterola

Keyword(s):

Solar Wind ◽

Geologic History ◽

Solar Si

En el pasado Marte tuvo una atmósfera más densa. Debido a la inexistencia de un campo magnético que protegiera la ionosfera y la exosfera del ataque del viento solar, éste erosionó la atmósfera marciana. Se propone un modelo que describe esta erosión a lo largo del tiempo geológico. Se concluye que: a) La cantidad de volátiles desgasificada en Marte fue del orden de 193.7 TAM (1 TAM = 1 Masa de la atmósfera terrestre = 5.28x1018 Kg). b) La cantidad de volátiles arrastrados por el viento solar, si la cronología larga es correcta, está en el intervalo de 0.472 a 1.89 TAM. c) La cantidad de volátiles arrastrados por el viento solar, si la cronología corta es correcta, está en el intervalo de 0.0624 a 0.25 TAM. d) La cantidad de volátiles arrastrada por el viento solar es mucho menor que la masa desgasificada. Por lo tanto, el arrastre ejercido por el viento solar no explica la mayor parte de los volátiles perdidos por Marte.

Download Full-text

Saturn's E, G and F rings: modulated by the plasma sheet

International Astronomical Union Colloquium ◽

10.1017/s0252921100101666 ◽

1984 ◽

Vol 75 ◽

pp. 597

Author(s):

E. Grün ◽

G.E. Morfill ◽

T.V. Johnson ◽

G.H. Schwehm

Keyword(s):

Solar Wind ◽

Direct Contact ◽

Transport Processes ◽

Time Variable ◽

Dust Particles ◽

Spatial Diffusion ◽

Drag Forces ◽

Orbit Perturbation ◽

Time Variations ◽

F Ring

ABSTRACTSaturn's broad E ring, the narrow G ring and the structured and apparently time variable F ring(s), contain many micron and sub-micron sized particles, which make up the “visible” component. These rings (or ring systems) are in direct contact with magnetospheric plasma. Fluctuations in the plasma density and/or mean energy, due to magnetospheric and solar wind processes, may induce stochastic charge variations on the dust particles, which in turn lead to an orbit perturbation and spatial diffusion. It is suggested that the extent of the E ring and the braided, kinky structure of certain portions of the F rings as well as possible time variations are a result of plasma induced electromagnetic perturbations and drag forces. The G ring, in this scenario, requires some form of shepherding and should be akin to the F ring in structure. Sputtering of micron-sized dust particles in the E ring by magnetospheric ions yields lifetimes of 102to 104years. This effect as well as the plasma induced transport processes require an active source for the E ring, probably Enceladus.

Download Full-text

Quantitative surface damage studies by H.R.E.M.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010015513x ◽

1989 ◽

Vol 47 ◽

pp. 632-633

Author(s):

S. R. Singh ◽

H. J. Fan ◽

L. D. Marks

Keyword(s):

Solar Wind ◽

Quantitative Analysis ◽

Surface Science ◽

Surface Damage ◽

Space Environment ◽

Oxygen Desorption ◽

The Past ◽

Diffusion Controlled ◽

Original Observation ◽

Substantial Interest

Since the original observation that the surfaces of materials undergo radiation damage in the electron microscope similar to that observed by more conventional surface science techniques there has been substantial interest in understanding these phenomena in more detail; for a review see. For instance, surface damage in a microscope mimics damage in the space environment due to the solar wind and electron beam lithographic operations.However, purely qualitative experiments that have been done in the past are inadequate. In addition, many experiments performed in conventional microscopes may be inaccurate. What is needed is careful quantitative analysis including comparisons of the behavior in UHV versus that in a conventional microscope. In this paper we will present results of quantitative analysis which clearly demonstrate that the phenomena of importance are diffusion controlled; more detailed presentations of the data have been published elsewhere.As an illustration of the results, Figure 1 shows a plot of the shrinkage of a single, roughly spherical particle of WO3 versus time (dose) driven by oxygen desorption from the surface.

Download Full-text