WE KNOW IT BECAUSE
OF THE CLUES THEY LEFT
BEHIND, BURIED IN
EARTH’S ROCKS.
BUT WHY DID THE
MASS EXTINCTION
HAPPEN?
ARE THESE EVENTS
ENOUGH TO CAUSE MASS
EXTINCTION?
UNLIKELY. HOWEVER,
THEY COULD HAVE STARTED A
CHAIN OF EVENTS THAT LED
TO BIG CHANGES IN THE
WORLD’S CLIMATE.
WHEN DID
THIS HAPPEN?
ABOUT 250 MILLION
YEARS AGO. IT THEN TOOK MORE
THAN 20 MILLION YEARS FOR
EARTH TO RECOVER.
40
Sep 2018
Some may
HAVE BEEN SET OFF BY
MASSIVE COLLISIONS between
the Earth and the meteors,
and some may have been a
result of huge VOLCANIC
ERUPTIONS.