Chicxlub Impact Crater: Princeton model shows fallout of a giant meteorite strike

The Princeton model shows (at left) that the structure of the Earth's surface at the time of the meteorite impact that caused the Chicxulub crater in Mexico would have placed the Deccan Traps in India far west of the crater's antipodal point, instead of directly opposite of the impact. 

Correspondingly, the model shows (at right) that the meteorite struck far east of the antipodal point for the Deccan Traps, which are remnants of large volcanoes thought to have contributed to the mass extinction event at the end of the Cretaceous period. 

The model also revealed that the Chicxulub impact, when the Earth's surface and shape are considered, would have likely been too small to cause the Deccan Traps. (Images by Conor Myhrvold)

Seeking to better understand the level of death and destruction that would result from a large meteorite striking the Earth, Princeton University researchers have developed a new model that can not only more accurately simulate the seismic fallout of such an impact, but also help reveal new information about the surface and interior of planets based on past collisions.

Princeton researchers created the first model to take into account Earth's elliptical shape, surface features and ocean depths in simulations of how seismic waves generated by a meteorite collision would spread across and within the planet.

Current projections rely on models of a featureless spherical world with nothing to disrupt the meteorite's impact, the researchers report in the October issue of Geophysical Journal International.

The researchers, based in the laboratory of Jeroen Tromp, the Blair Professor of Geology in Princeton's Department of Geosciences, simulated the meteorite strike that caused the Chicxulub crater in Mexico, an impact 2 million times more powerful than a hydrogen bomb that many scientists believe triggered the mass extinction of the dinosaurs 65 million years ago.

The team's rendering of the planet showed that the impact's seismic waves would be scattered and unfocused, resulting in less severe ground displacement, tsunamis, and seismic and volcanic activity than previously theorised.

The Princeton simulations also could help researchers gain insight into the unseen surface and interior details of other planets and moons, the authors reported.

The simulations can pinpoint the strength of the meteorite's antipodal focus - the area of the globe opposite of the crater where the energy from the initial collision comes together like a second, smaller impact.

The researchers found this point is determined by how the features and composition of the smitten orb direct and absorb the seismic waves.

Scientists could identify the planet or moon's characteristics by comparing a crater to the remnants of the antipodal point and calculating how the impact waves spread.

Lead author Matthias Meschede of the University of Munich developed the model at Princeton through the University's Visiting Student Research Collaborators program with co-authors Conor Myhrvold, who earned his bachelor's degree from Princeton in 2011, and Tromp, who also is director of Princeton's Institute for Computational Science and Engineering and a professor of applied and computational mathematics. Meschede describes the findings as follows:

NASA's Zero-G carry Princeton University teachers: PPPL lets teachers hitch a ride

As part of a Princeton-sponsored team, Miller and Williams were flying at that moment on a NASA aircraft modified to simulate a reduced-gravity environment.

They were there to study how microgravity affected the movement of the pendulum, crafted from a softball, and the dynamics of the bubbles, all of which were contained in a clear plastic box.



PPPL team members Susan Franko of Gregory Elementary School in Trenton (left) and Patty Hillyer (center, in red T-shirt) of Matawan-Aberdeen Middle School in Cliffwood observe their experimental box on the zero-gravity flight.

The teachers had journeyed to NASA Johnson Space Center's Ellington Field in Houston to conduct experiments along with some 80 participants in NASA's Reduced Gravity Education Flight Program July 22-29.

The U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL) sponsored six of the dozen teams, including one dubbed the "Space Cowboys" with Miller, Williams and four others. In total, PPPL sponsored about 40 participants, including teachers from various New Jersey school districts and researchers from the lab.

"Many of the teachers, for the first time, designed, built and performed an actual scientific experiment," said PPPL Science Education Program Head Andrew Zwicker, who rode the Zero-G aircraft twice with this year's K-12 educators. "They plan to use the experience, and the curricula they designed based upon their experiments, in their classrooms."

Princeton University - PPPL lets teachers hitch a ride on NASA's Zero-G

Darwinian Nodes of Action

Charles Darwin
The principles of life on Earth may also be applied to life on other planets, with some exceptions. I am including here an extract from Marc D Hauser's book on Moral Minds. He is influenced in turn by the work of Eduard Tinkelpaugh, the 1920's psychologist, famous for his work with examining the intelligence levels of primates and monkeys.

'We do not know what it is like to have a primate experience of expectation, satisfaction and dissatisfaction. Tinkelpaugh proposed that the primate brain has evolved to respond to actions and events and set up expectations about, the causes and consequences to detect violations, using mimicry, learned behaviour and experiences.

I have listed the 5 principles of living as a primate, emanating from the studies of Tinkelpaugh, Darwin and others. These studies involved intelligent animals, primarily primates but occasionally dolphins and birds (Ravens and Jays).

Principle 1 - If an object moves on its own, it is an animal or part of an animal

Principle 2 - If an object moves in a particular direction towards another object or location, the targeted direction picks out or implies the object's goal

Principle 3 - If an object moves 'flexibly', changing direction in response to environmental objects or events, then it is rational

Principle 4 - If one object's action is followed closely by a second object's action, the second object's action is perceived as a socially intelligent response

Principle 5 - If an object is self-propelled, goal-directed and flexibly responsive to environmental constraints and events, then the object has the potential to cause harm or comfort to other similar objects.

Now you have some insight into the simple rules of thought and behaviour a primate is subject to. Can we now apply these principles more wildly and include them in the search for socially intelligent extra-terrestrial life?