Attogram dust cloud a million kilometers from Comet Halley

Utterback, N. G.; Kissel, J.

doi:10.1086/115599

Cited by 59 publications

(34 citation statements)

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“…This relationship has previously been shown to be valid for micron-sized dust particles down to 0.1 μm (Fink & Rubin 2012) and is extrapolated down to nanoparticles for our analysis. The extrapolated total nanoparticle mass loss rate agrees with measurements from Utterback & Kissel (1990), but it is possible that nanoparticle distributions may behave independently from micron-sized grains. We therefore use this empirical proportionality for our initial results and then will vary nanoparticle densities as a free parameter when comparing to Chandra data.…”

Section: Composition Of Cometary Atmospheresupporting

confidence: 62%

“…Their density is usually considered in analyses of dust-to-gas ratios in atmospheres of different comets. Nano-sized dust and ice particle densities and composition ratios are not as well-established because of a lack of precise observational data for such small masses (Utterback & Kissel 1990). Nanoparticles also efficiently scatter X-rays because their grain geometric sizes are on the same scale as the photon wavelengths (Krasnopolsky et al 2004;Draine 2003) and are therefore the focus of our scattering calculations.…”

Section: Composition Of Cometary Atmospherementioning

confidence: 99%

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Cometary emissions induced by scattering and fluorescence of solar X-rays

Snios

Lewkow

Kharchenko

2014

A&A

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To establish the nature of cometary X-ray emissions above 1 keV, detailed modeling of scattering and fluorescence of solar X-rays by a cometary atmosphere is carried out over the 0.3−3.0 keV photon energy range. Computations of the X-ray emissions are performed for different distributions of the cometary neutral gas, dust, and ice grains, with an emphasis placed on nano-sized particles. The calculated emission spectra of energetic photons above 1 keV are compared to cometary observations performed by the Chandra X-ray Observatory, and emission contributions solely from cometary neutral gas are found to be an insufficient X-ray production mechanism. Further comparison between the developed model and observational data also establishes an upper limit on dust and ice nanoparticle density distributions in cometary atmospheres. In addition, similarities in spectral shape above 1 keV observed between cometary emissions, Jovian disk emissions, and scattered solar X-ray spectra during solar flare events are discussed in detail.

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Section: Composition Of Cometary Atmospheresupporting

confidence: 62%

Section: Composition Of Cometary Atmospherementioning

confidence: 99%

Cometary emissions induced by scattering and fluorescence of solar X-rays

Snios

Lewkow

Kharchenko

2014

A&A

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“…In these cases, the nano dust is detected by in situ measurements. During the space missions to comet Halley, dust measurements on the Vega and Giotto spacecraft suggested the presence of dust particles of 1-10 nm size in the vicinity of the comet (Utterback & Kissel 1990). The Ulysses dust experiment detected nano particles ejected from the Jovian magnetosphere (see Grün et al 1993;Krüger et al 2006b, and references therein); these nano particles were also detected by the Cassini plasma wave experiment (Meyer-Vernet et al 2009b).…”

Section: Introductionmentioning

confidence: 97%

Formation and Acceleration of Nano Dust in the Inner Heliosphere

Czechowski

Mann

2010

ApJ

132

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We study the dynamics of nano dust grains in the region inward from 1 AU. Assuming that the grains are created with the velocities close to Keplerian, we find that, despite the strong coupling to magnetic field, there is a population of trapped nano grains within about 0.2 AU from the Sun. The nano dust grains produced outside of the trapped region are accelerated to high velocities, of the order of 300 km s −1 , provided that the charge to mass ratio is not much less than 10 −5 e/m p . These values correspond to dust sizes equal or smaller than approximately 10 nm.

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“…While in principle the element composition of the dust can be inferred from the mass composition of the detected ions, this is complicated by the fact that the impact vapor contains both the dust and the spacecraft (target) material and that the impact ionization process is not well understood. The element composition of the cometary dust was firstly derived from space measurements based on mass spectra obtained during the space missions to comet Halley [224,225] (see discussion below). More recent measurements with the Cassini Cosmic Dust Analyser (CDA) experiment primarily deal with dust particles in the vicinity of Saturn, for a review see [89].…”

Section: Dust and Meteoroids Entering Earth Atmospherementioning

confidence: 99%

Dust in the planetary system: Dust interactions in space plasmas of the solar system

Mann¹,

Meyer‐Vernet²,

Czechowski³

2014

Physics Reports

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Cosmic dust particles are small solid objects observed in the solar planetary system and in many astronomical objects like the surrounding of stars, the interstellar and even the intergalactic medium. In the solar system the dust is best observed and most often found within the region of the orbits of terrestrial planets where the dust interactions and dynamics are observed directly from spacecraft. Dust is observed in space near Earth and also enters the atmosphere of the Earth where it takes part in physical and chemical processes. Hence space offers a laboratory to study dust plasma interactions and dust dynamics. A recent example is the observation of nanodust of sizes smaller than 10 nm. We outline the theoretical considerations on which our knowledge of dust electric charges in space plasmas are founded. We discuss the dynamics of the dust particles and show how the small charged particles are accelerated by the solar wind that carries a magnetic field. Finally, as examples for the space observation of cosmic dust interactions, we describe the first detection of fast nanodust in the solar wind near Earth orbit and the first bi-static observations of PMSE, the radar echoes that are observed in the Earth ionosphere in the presence of charged dust.

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Attogram dust cloud a million kilometers from Comet Halley

Cited by 59 publications

References 0 publications

Cometary emissions induced by scattering and fluorescence of solar X-rays

Cometary emissions induced by scattering and fluorescence of solar X-rays

Formation and Acceleration of Nano Dust in the Inner Heliosphere

Dust in the planetary system: Dust interactions in space plasmas of the solar system

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