At a conference of planetologists in Nantes, the astronomer Pedro Lacerda reported, that about a fifth of the asteroids, located in the Kuiper belt beyond Neptune, may be double, representing the two asteroids that revolve around a common center of mass is so close that relate to each other and resembling in shape of "hourglass." This assumption was made based on analysis of changes in brightness of some asteroids of the Kuiper belt, in particular the asteroid 2001QG298. Brightness fluctuations can be explained by the fact, that this asteroid is an asteroid from two asteroids. It is estimated, that these asteroids must be at least 25% in the Kuiper belt.