INTERSTELLAR & INTERPLANETARY MATTER A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z                    HOME ABOUT CATEGORIES SITE MAP COPYRIGHT ADVERTISE CONTACT entire Web this site interstellar cloud A local concentration of gas and dust between the stars. Although space is never completely empty (see interstellar medium), matter in the form of atoms, molecules, and cosmic dust particles is clumped together more densely in interstellar clouds. These are of two main types: molecular clouds and HI regions. Related category    • INTERSTELLAR AND INTERPLANETARY MATTER Also on this site: Encyclopedia of Alternative Energy & Sustainable Living Encyclopedia of History Transport Concepts & Designs (partner site) BACK TO TOP