Cometary cloud

The theory posits a vast spherical cloud of icy comets surrounding the solar system up to 2 light-years away. This would explain the continued presence of comets despite their short-lived appearances near the sun.
 Jan Hendrik Oort Netherlands 1950 Cometary cloud

The theory posits a vast spherical cloud of icy comets surrounding the solar system up to 2 light-years away. This would explain the continued presence of comets despite their short-lived appearances near the sun.