[meteorite-list] Chaos Clues To Dino Demise

From: Michael Masse <mjmasse_at_meteoritecentral.com>
Date: Thu Apr 22 09:44:14 2004
Message-ID: <000601c0ff3a$f5da89e0$25070518_at_default.elcjn1.sdca.home.com>

Hi...as chaos math will produce varing answers if minor
parameters are changed is it possible that the math is
selected to support the theory?...also, any suggestions
what will change planetary system dynamics enough
for a single impactor?...do we have datable lunar impacts
in the same time range?....????

-----Original Message-----
From: Ron Baalke <baalke_at_zagami.jpl.nasa.gov>
To: Meteorite Mailing List <meteorite-list_at_meteoritecentral.com>
Date: Wednesday, June 27, 2001 9:55 AM
Subject: [meteorite-list] Chaos Clues To Dino Demise


>
>
>http://news.bbc.co.uk/hi/english/sci/tech/newsid_1409000/1409305.stm
>
>Chaos clues to dino demise
>By Helen Briggs
>BBC News
>June 27, 2001
>
>A mysterious disturbance in the forces at the heart of the Solar System
>could have triggered the asteroid that wiped out the dinosaurs.
>
>This intriguing new theory has been put forward by scientists who have
>calculated the paths of the planets over the past 100 million years.
>
>A US team believes a change in the dynamics of the Solar System caused
>Mercury, the Earth and Mars to veer off course.
>
>This could have pushed a giant asteroid towards our planet, spelling
>downfall for most living things, 65 million years ago.
>
>The idea has been floated by a team of astrobiologists at the University of
>California, Los Angeles (UCLA), based on simulations of the historical
>positions of the major planets.
>
>"Our best calculations show that the dynamical state of the inner Solar
>System changed abruptly about 65 million years ago," said Bruce Runnegar,
>director of UCLA's centre for Astrobiology.
>
>Chaos theory
>
>The event modified the average orbit of Mercury, Mars and the Earth in
>significant ways, he said, possibly perturbing asteroids in the inner part
>of the asteroid belt and throwing one or more of them into Earth-crossing
>orbits.
>
>"Thus, the ultimate cause of the K-T impact [and the demise of the
>dinosaurs] may have been caused by a chaos-induced change in Solar System
>dynamics," Dr Runnegar told BBC News Online.
>
>The basis of the theory, deduced by team members Ferenc Varadi and Michael
>Ghil, is chaos in the Solar System.
>
>Under this scenario, a small shift in the orbit of one or more planets
could
>destabilise much of the Solar System. To test their theory, the researchers
>simulated the orbits of the major planets, working back in history over
tens
>of millions of years.
>
>To their surprise, computer models pointed to a change in the dynamics of
>the inner Solar System at the time of the K-T (Cretaceous-Tertiary) mass
>extinction, about 65 million years ago, when many plants and animals
>suddenly became extinct.
>
>Dr Runnegar said they were now carrying out further studies to test their
>theory.
>
>"At the moment the link with the dinosaurs is based on a coincidence in
time
>and a plausible mechanism," he added.
>
>'Tenuous' link
>
>The research, presented at the Earth System Processes meeting in Edinburgh,
>UK, has received a mixed reaction from other experts.
>
>Professor Mark Bailey of the Armagh Observatory, Armagh, said the asteroid
>link appeared tenuous, but not impossible.
>
>"[It] relies not least on the assumption that the killer projectile was an
>asteroid and not a comet," he told BBC News Online.
>
>"Nevertheless, the idea that the resonant frequencies of the Solar System
>change chaotically on time-scales of tens to hundreds of millions of years
>(albeit only slowly and by relatively small amounts) is an interesting one
>which adds yet another wrinkle to the story of our changing Solar System."
>
>Professor Carlos Frenk, an astrophysicist at the University of Durham, UK,
>said the theory appeared plausible.
>
>"If these calculations are correct, they are very revealing of the unusual
>past behaviour of the Solar System," he told BBC News Online.
>
>"The past history of the Solar System was not as quiet as we thought - this
>very unusual chaotic behaviour may have happened on our doorstep."
>
>_______________________________________________
>Meteorite-list mailing list
>Meteorite-list_at_meteoritecentral.com
>http://www.pairlist.net/mailman/listinfo/meteorite-list
Received on Wed 27 Jun 2001 02:57:05 PM PDT