In the Solar System , interplanetary dust particles ( IDPs ) originating mainly from asteroid collisions and cometary activities drift to the Earth orbit due to the Poynting-Robertson drag .
We analyzed the thermal emission from IDPs that was observed by the first Japanese infrared astronomical satellite , AKARI .
The observed surface brightness in the trailing direction of the Earth orbit is 3.7 % greater than that in the leading direction in the 9 \micron band and 3.0 % in the 18 \micron band .
In order to reveal dust properties causing the leading-trailing surface brightness asymmetry , we numerically integrated orbits of the Sun , the Earth , and a dust particle as a restricted three-body problem including radiation from the Sun .
The initial orbits of particles are determined according to the orbits of main-belt asteroids or Jupiter-family comets .
The orbital trapping in mean motion resonances results in a significant leading-trailing asymmetry so that intermediate sized dust ( \sim 10 – 100 \micron ) produces a greater asymmetry than the zodiacal light has .
The leading-trailing surface brightness difference integrated over the size distribution of the asteroidal dust is obtained to be the values of 27.7 % and 25.3 % in the 9 \micron and 18 \micron bands , respectively .
In contrast , the brightness difference for cometary dust is calculated as the values of 3.6 % and 3.1 % in the 9 \micron and 18 \micron bands , respectively , if the maximum dust radius is set to be s _ { max } = 3000 \micron .
Taking into account these values and their errors , we conclude that the contribution of asteroidal dust to the zodiacal infrared emission is less than \sim 10 \% , while cometary dust of the order of 1 mm mainly accounts for the zodiacal light in infrared .