Did you know?
" About 2,000 objects massive enough (1km in diameter) to cause
global catastrophe are known to cross Earth's orbit. The impact of
just one would wipe out 25% of humanity.
" Pea-sized meteoroids hit Earth at a rate of 10 per hour, 1km
asteroids strike on average once every 100,000 years.
" Whatever caused the extinction of the dinosaurs also caused the
death of around 70% of all of the species on the planet.
With its exciting mix of dinosaurs, death and outer space, the
whole world loved the impact theory - it is now generally accepted
as the truth. But new research is uncovering a different
story
Could one of the best known and most glamorous scientific theories
be wrong? Until recently most scientists thought they knew what
killed off the dinosaurs. It was a 10 kmwide meteorite which
smashed into Yucatan in Mexico. It caused world-wide forest fires,
tsunamis several kilometres high, and an 'impact winter' - in which
dust blocked out
the sun for months or years. It was thought the dinosaurs were
blasted, roasted, and frozen to death, in that order.
But now there is increasing evidence the impact theory could be
wrong. The suggestion has generated one of the bitterest scientific
rows of recent times. What Really Killed The Dinosaurs sets out to
sort the fact from the fiction.
The impact theory was beautifully simple and hugely appealing. But
a team of scientists led by Professor Gerta Keller of Princeton has
uncovered a series of geological clues which suggests the truth may
be far more complicated. She believes that the crater in the
Yucatan is too old to have killed off the dinosaurs. That opinion
sparked a massive
row, as the supporters of the impact theory such as Professor Jan
Smit of Amsterdam rubbished her ideas.
But Keller's work is attracting increasing support. A range of
scientists have begun to question other hypotheses connected with
the impact theory. They say the evidence just does not support the
belief that wildfires raged all around the world, that dinosaurs
perished amid acid rain as strong as battery acid, and that an
'impact winter' caused a massive and sustained drop in
temperature.
With stunning CGI graphics and the help of all the key scientists,
Horizon explores the growing body of evidence which raises
fundamental questions about the impact theory. It seems that the
death of the dinosaurs may have been more complex than we had
previously thought.
"This documentary perks up a pretty dry subject with plenty of
Walking With Dinosaurs-style footage
But surprise star of the
show is Britain's own Claire Belcher, a boffin from the University
of London who turns up with an even more startling discovery of her
own."
Daily Mirror
"Complex arguments laid out clearly
this was the best Horizon in
ages." Independent
