We consider the problem of the aerosol formation in the upper atmosphere from meteoroids which arrive in the Earth’s atmosphere and have masses from 10^-18 to 10^-8 g. Based on the analytical solutions of simplified classical equations of deceleration and heating of small meteoroids, we determined the maximal temperatures of the particles during their motions in the atmosphere and the altitudes at which they reach critically low velocities (so-called altitudes of stopping). We suppose that a space particle transforms into an aerosol one when it does not reach its melting temperature. As a base input characteristics, we have plotted the three-dimensional probability density distribution for the number of such particles as a function of the following parameters being critical for reaching by the particle its melting temperature: initial mass, velocity, and angle of entrance into the atmosphere. It is found that stone particles with initial masses less than 1.710^-14 g become aerosols independently on other parameters. By means of the transformation of the plotted distribution in accordance with simplified classical meteor physics equations, we derived a two-dimensional distribution over mass and formation altitude for the aerosol of space origin in the upper atmosphere.