Spectral and orbital survey of medium-sized meteoroids

Abstract

We investigate the spectra, material properties, and orbital distribution of millimeter- to decimeter-sized meteoroids. Our study aims to distinguish the characteristics of populations of differently sized meteoroids and reveal the heterogeneity of identified meteoroid streams. We verify the surprisingly large ratio of pure iron meteoroids on asteroidal orbits detected among mm-sized bodies. Emission spectra and multi-station meteor trajectories were collected within the AMOS network observations. The sample is based on 202 meteors of -1 to -14 magnitude, corresponding to meteoroids of mm to dm sizes. Meteoroid composition is studied by relative intensity ratios of Na, Mg, and Fe. Heliocentric orbits, trajectory parameters, and material strengths inferred from empirical $K_B$ and $P_E$ parameters were determined for 146 meteoroids. An overall increase of Na content compared to the population of mm-sized meteoroids was detected, reflecting weaker effects of space weathering processes on larger meteoroids. We report a very low ratio of pure iron meteoroids and the discovery of a new spectral group of Fe-rich meteors. The majority of meteoroids on asteroidal orbits were found to be chondritic. Thermal processes causing Na depletion and physical processes resulting in Na-rich spectra are described and linked to characteristically increased material strengths. Numerous major and minor shower meteors were identified in our sample, revealing various degrees of heterogeneity within Halley-type, ecliptical, and sungrazing meteoroid streams. Our results imply a scattered composition of the fragments of comet 2P/Encke and 109P/Swift-Tuttle. The largest disparities were detected within the $\alpha$-Capricornids and $\delta$-Aquarids. We also find a spectral similarity between $\kappa$-Cygnids and Taurids, which could imply a similar composition of the parent objects of the two streams.

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Cited by in corpus (13)

• Data on 824 fireballs observed by the digital cameras of the European Fireball Network in 2017-2018. II. Analysis of orbital and physical properties of centimeter-sized meteoroids
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• Characterization of the June epsilon Ophiuchids meteoroid stream and the comet 300P/Catalina
• Hydrogen emission from meteors and meteorites: mapping traces of H${}_2$O molecules and organic compounds in small Solar system bodies
• Oxygen line in fireball spectra and its application to satellite observations
• Iron Rain: measuring the occurrence rate and origin of small iron meteoroids at Earth
• Spectral properties of ablating meteorite samples for improved meteoroid composition diagnostics
• Analysis of CN emission as a marker of organic compounds in meteoroids using laboratory simulated meteors
• Ultraviolet Observations of Comet 96/P Machholz at Perihelion
• Quantifying the Bulk Density of Southern Delta Aquariid Meteoroids: Insights from the Canadian Automated Meteor Observatory
• Possibility of transporting material from Ceres to NEO region via 8:3 MMR with Jupiter
• Meteor clusters: tracing meteoroid fragmentation in near-Earth space
• Meteors: Light from Comets and Asteroids