IRAS observations show that the Earth is embedded in a solar ring of asteroidal dust particles in resonant lock with the planet

We have analyzed all the infrared observations of the zodiacal cloud obtained in 1983 by the Infrared Astronomical Satellite (IRAS) and shown that when viewed at a constant elongation angle of 90 degrees, the elliptic brightness of the cloud is systematically greater by approx. 3 percent in the trailing direction than in the leading direction. This asymmetry is observed at all times of the year and in all three of the IRAS wavebands in which the zodiacal cloud is clearly observed. The orbits of cometary particles are highly eccentric and these particles are unlikely to be trapped in corotational resonances. Thus, the IRAS observations are evidence that the Earth is embedded in a ring of asteroidal particles. Similar rings are expected to be associated with Mars and Venus. The existence of asteroidal families and their associated dust bands (also discovered by IRAS) are evidence that the asteroid belt is a significant and maybe the dominant source of dust in the zodiacal cloud. These new observations give quantitative information both on the rate of transport of asteroidal dust to the Earth and on the rate of grinding down of the asteroid belt. Without resonant trapping most dust particles spiral past the Earth without striking the planet. However, most particles trapped in resonances are released from these resonances due to close encounter with the Earth. Thus, the ring may act as a funnel through which asteroidal particles are deposited in the Earth's atmosphere. This could have implications for the efficiency of the transport of carbonaceous material from the asteroid belt to the Earth and for the origin of life on the planet.