Large, transient decreases of atmospheric dayglow intensities at ultraviolet wavelengths, primarily the atomic oxygen emissions at 130.4 nm, are interpreted in terms of an influx of heretofore undetected comet-like objects. The primary composition of these comet-like objects is water snow or clathrate in the form of a fluffy aggregate. These small comets are covered with a dust mantle and the tensile stress at fracture is estimated to be ~ 0.1 dyne/cm2. The water molecules that form the absorbing blanket for ultraviolet emissions arrive at the top of the earth's atmosphere as a piston of gas with bulk speed <20 km/sec. The mass of each of these comet-like objects is ~ 108 gm, or ~ 100 tons. The global influx rate is - 20 comets per minute.The global mass accretion rate by the earth's atmospheric mass in ~ 5¿106 years. The earth and the other bodies in the solar system would be thus more strongly coupled to cometary matter than presently thought.