e said  t cloud is t it starts someretco t ofmeasure in tem is tronomical Unit, or AU, representing tance from*Properly called t cloud, it is named for tonian astronomer Ernst Opik, ence in 1932, and for tcronomer Jan Oort, wions eiger.

    to to is about forty AUs from us, t of t cloud about fiftyt is remote.

    But let’s pretend again t o t cloud. t tnotice is  is out  it’s not even test star in t is a remarkable t t tdistant tiny to s in orbit. It’s not a very strongbond, so ts drift in a stately manner, moving at only about 220 miles an ime to time some of ts are nudged out of t by some sligational perturbation—a passing star perimes ted into tiness of space, never to be seen again, but sometimes to a long orbit aroundt ts, pass tem. Just occasionally tray visitors smack into somet’s oer of tem. It is  is going to take a long time to get tleast—so  for nourn to it mucer in tory.

    So t’s your solar system. And  tem? ell,not deal, depending on  it.

    In t term, it’s not perfect vacuum ever created by  asempty as tiness of interstellar space. And t deal of tilyou get to t bit of somet neigauri,ar cluster knoerms, but t is still a imes fartrip to the Moon.

    to reac by spacesake at least ty-five trip you still  be any a lonely clutcars in t no-years of travel. And so it ried to star-he cosmos.

    Just reacer of our oake far longer ted asbeings.

    Space, let me repeat, is enormous. tance betars out t speeds approac, tasticallycances for any trav