Clues in Zodiacal Light Observations for a Dust Ring Along the Earth's Orbit

Abstract The ability of the Earth to trap interplanetary grains into a dust ring lying along the terrestrial orbit was shown by numerical simulations and confirmed by infrared observations (IRAS, COBE). Such a ring could have its signature on the elongation dependence of the zodiacal brightness along the ecliptic, especially near 90° of the Sun. Indeed, the elongation dependence observed at Tenerife by Dumont and Sanchez (1975) shows that the space density of interplanetary dust slightly increases with increasing heliocentric distance, within the 2 or 3 hundredths of AU approaching Earth's orbit.