unamis ingly for distant s, and burning rock and oting doing muc ablaze. It imatedt at least a billion and a  day. turbances to t communications systems everyurn. It er. As one commentator  it, fleeing ing a slooll tle affected by any plausible relocation effort, sinceEarty to support life would be universally diminished.”

    t of soot and floating as and follo out tainly for monting groitute of tecopes from sediments left from ter Kt impact and concluded t it affected Earte for about ten thousand years.

    tually used as evidence to support tion t tinction of dinosaurs  and empic—and so it erms. e can only guess y .

    And in all likeli  of a clear sky.

    But let’s assume  coming.   to smit, as Joes, our missiles are not designed for space  to escape Earty and, even if toguide tens of millions of miles of space. Still less could  po t could,Saturn 5, ired years ago and urn launcroyed as part of aNASA housecleaning exercise.

    Even if  a eroid and blasted it to pieces,t urn it into a string of rocks t o us oneafter t Ser—but  noensely radioactive. tom Geeroid er at ty of Arizona, t even a year’s  totake appropriate action. ter likeli  see any object—even a comet—until it  six montoo late.

    Sing Jupiter in a fairly conspicuous manner since 1929, but ittook over ury before anyone noticed.

    Interestingly, because t to compute and must incorporate suc margin of error, even if  il nearly t couple of weeks anyway—wain.

    For most of time of t’