IRAS observations of the zodiacal background

The Infrared Astronomical Satellite (IRAS) sky survey measurements are used to constrain a model for the interplanetary dust emission. Efforts to date, although hampered somewhat by calibration uncertainties, indicate that the cloud is inclined to the ecliptic by approximately 1.7° with its line of ascending nodes at 70° ecliptic longitude. The data is well fit by a dust density distribution described in cloud symmetry plane coordinates by p = p_o (r_o/r)^1.1 exp −4.2 (z/r)^1.2], where the dust has a gray emissivity and an equilibrium temperature at 1 AU of 280 K.