A star passing within similar to 10(4) AU of the Sun would trigger a c
omet shower that would reach the inner solar system about 0.18 Myr lat
er. We calculate an a priori probability of similar to 0.4% that a sta
r has passed this close to the Sun but that the comet shower has not y
et reached the Earth. We search the Hipparcos catalogue for such recen
t close-encounter candidates and, in agreement with Garcia-Sanchez et
al., find none. The new result reported in this Letter is an estimatio
n of the completeness of the search. Because of the relatively bright
completeness limit of the catalogue itself, V similar to 8, the search
is sensitive to only about half the stars that could have had such a
near encounter. On the other hand, we show that the search is sensitiv
e to nearly all of the past encounters that would lead to a major show
er in the future and conclude that it is highly unlikely that one will
occur during the next 0.5 Myr.