▁empty ▁regions ▁of ▁the ▁universe ▁outside ▁the ▁atmos pher es ▁of ▁cel est ial ▁bodies . ▁Out er ▁space ▁is ▁used ▁to ▁distinguish ▁it ▁from ▁air space ▁( and ▁terrest rial ▁locations ). ▁There ▁is ▁no ▁discrete ▁boundary ▁between ▁the ▁Earth ' s ▁atmosphere ▁and ▁space , ▁as ▁the ▁atmosphere ▁gradually ▁at ten u ates ▁with ▁increasing ▁alt itude . ▁Out er ▁space ▁within ▁the ▁Sol ar ▁System ▁is ▁called ▁inter plan et ary ▁space , ▁which ▁passes ▁over ▁into ▁inter stell ar ▁space ▁at ▁what ▁is ▁known ▁as ▁the ▁hel iop ause . ▁ ▁Out er ▁space ▁is ▁sp ars ely ▁filled ▁with ▁several ▁dozen ▁types ▁of ▁organ ic ▁mole cules ▁discovered ▁to ▁date ▁by ▁mic row ave ▁spect ro sc opy , ▁black body ▁radiation ▁left ▁over ▁from ▁the ▁Big ▁Bang ▁and ▁the ▁origin ▁of ▁the ▁universe , ▁and ▁cos mic ▁ray s , ▁which ▁include ▁ion ized ▁atomic ▁nuc lei ▁and ▁various ▁sub atomic ▁particles . ▁There ▁is ▁also ▁some ▁gas , ▁pl asma ▁and ▁dust , ▁and ▁small ▁met e ors . ▁Additionally , ▁there ▁are ▁signs ▁of ▁human ▁life ▁in ▁outer ▁space ▁today , ▁such ▁as ▁material ▁left ▁over ▁from ▁previous ▁man ned ▁and ▁un mann ed ▁launch es ▁which ▁are ▁a ▁potential ▁ha z ard ▁to ▁space craft . ▁Some ▁of ▁this ▁de br is ▁re - ent ers ▁the ▁atmosphere ▁period ically . ▁ ▁Although ▁the ▁Earth ▁is ▁the ▁only ▁body ▁within ▁the ▁solar ▁system ▁known ▁to ▁support ▁life , ▁evidence ▁suggests ▁that ▁in ▁the ▁distant