Monte Carlo modeling of sodium in Mercury’s exosphere during the first two MESSENGER flybys

Burger, M. H.; Killen, R. M.; Vervack, R. J.; Bradley, E. T.; McClintock, W. E.; Sarantos, M.; Benna, M.; Mouawad, N.

doi:10.1016/j.icarus.2010.05.007

Cited by 48 publications

(69 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The ratio between the volume of melt and volume of vapor depends on the impact velocity as well as other impactor, surface, and impact-related parameters. At the moment, the impact vaporisation rate at Mercury is highly uncertain because of uncertainties in the density and velocity distribution of the interplanetary dust and the vapor production rate of the impacting dust particles (Burger et al 2010). Recent works suggest that the enhancement in Ca at 25…”

Section: Discussionmentioning

confidence: 99%

Statistical analysis of the flux of micrometeoroids at Mercury from both cometary and asteroidal components

Borin

Cremonese

Marzari³

2016

A&A

View full text Add to dashboard Cite

Context. Meteoroid impacts are an important source of neutral atoms for the exosphere of Mercury. We previously estimated the contribution of meteoroids originating in the asteroid belt for vapor release. In this paper, we concentrate on the cometary component of particles impacting the planet. Comets and asteroids are considered to be the two major sources of interplanetary dust particles in the solar system. The debate about which source contributes most to dust populating the solar system is still ongoing. Aims. In this work, we compute the orbital evolution of dust particles produced by Jupiter-family comets (JFC) via N-body numerical integrations. From our numerical simulations, we compute the fraction of particles hitting Earth and Mercury's surface and the corresponding distribution of impact velocities. According to some authors more than 80% of all the incoming mass of meteoroids entering the Earth's atmosphere is concentrated in the mass range 10 −7 −10 −3 g. In our model, we considered a slightly different range, 10 −9 to 10 −6 g, to include possible uncertainty. Methods. The orbital evolution of dust particles of different sizes is computed with a numerical integration code, which includes the effects of Poynting-Robertson drag, solar wind drag, and planetary perturbations. Results. By comparing the impact frequency of grains evolving either from main belt asteroids or JFC we find that the cometary component is significantly less efficient in releasing dust particles on Mercury than on the Earth. The opposite occurs in the case of dust coming from the main belt with a flux higher at Mercury than on the Earth. This is mostly due to the different dynamical histories of the grains from their release until impact. This may have important implications for the vapor production rate on Mercury. We compare our results with previous estimates given by different authors.

show abstract

Section: Discussionmentioning

confidence: 99%

Statistical analysis of the flux of micrometeoroids at Mercury from both cometary and asteroidal components

Borin

Cremonese

Marzari³

2016

A&A

View full text Add to dashboard Cite

show abstract

“…An impact flux 170 times the Cintala rate would either overwhelm the exosphere, or we would have to conclude that impact vaporization is either less efficient than previously estimated, that impact vapor quickly condenses, leaving only 2% of the vapor in the exosphere, or that the vaporization products are not fully measured, possibly being in molecular form. The distribution of various elements in the exosphere appears to be inconsistent with uniform impact vaporization by micrometeoroids (e.g., Burger et al, 2010), mainly because of high-latitude enhancements, a dawn enhancement in Ca, and rapid variability.…”

Section: Impact Vaporization At the Time Of M2mentioning

confidence: 96%

Observations of metallic species in Mercury’s exosphere

Killen

Potter

Vervack

et al. 2010

Icarus

Self Cite

View full text Add to dashboard Cite

a b s t r a c tFrom observations of the metallic species sodium (Na), potassium (K), and magnesium (Mg) in Mercury's exosphere, we derive implications for source and loss processes. All metallic species observed exhibit a distribution and/or line width characteristic of high to extreme temperature -tens of thousands of degrees K. The temperatures of refractory species, including magnesium and calcium, indicate that the source process for the atoms observed in the tail and near-planet exosphere are consistent with ion sputtering and/or impact vaporization of a molecule with subsequent dissociation into the atomic form. The extended Mg tail is consistent with a surface abundance of 5-8% Mg by number, if 30% of impact-vaporized Mg remains as MgO and half of the impact vapor condenses. Globally, ion sputtering is not a major source of Mg, but locally the sputtered source can be larger than the impact vapor source. We conclude that the Na and K in Mercury's exosphere can be derived from a regolith composition similar to that of Luna 16 soil (or Apollo 17 orange glass), in which the abundance by number is 0.0027 (0.0028) for Na and 0.0006 (0.0045) for K.Published by Elsevier Inc.

show abstract

“…Burger et al (2010) found that the primary source of sodium during M1 was photon-stimulated desorption by solar ultraviolet (UV) radiation, a process described by Madey et al (1998). The rate at which sodium atoms are desorbed depends on the UV flux to the surface and the concentration of sodium atoms .…”

Section: Modeling Mercury's Exospherementioning

confidence: 99%

“…Sunlight can desorb atoms only from the first few monolayers of the grains, and the high solar flux at Mercury's orbit rapidly depletes the sodium at the extreme surface of the grains (Killen et al, 2004). Burger et al (2010) estimated the diffusion-limited flux of sodium at the subsolar point to be 10 6 -10 7 Na cm À2 s À1 depending on their assumptions regarding surface sticking and thermal accommodation coefficients.…”

Section: Modeling Mercury's Exospherementioning

confidence: 99%

“…Mercury's magnetosphere can be open to the solar wind over significant areas, and solar wind plasma can therefore reach the surface and sputter material to the exosphere (e.g., Ip, 1993;Lammer and Bauer, 1997;Killen et al, 2001;Sarantos et al, 2001). Burger et al (2010) have shown that, at least during the MESSENGER flybys, PSD is the dominant source of Na with its source rate enhanced in regions of open field lines by ion precipitation, a process that was first proposed by Potter et al (2000). Mura et al (2009) found similar results while studying transit data by Schleicher et al (2004).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation