Free Newsletters - Space News - Defense Alert - Environment Report - Energy Monitor
. 24/7 Space News .




DEEP IMPACT
CU study provides new evidence ancient asteroid caused global firestorm on Earth
by Staff Writers
Boulder CO (SPX) Mar 29, 2013


A new CU-Boulder study shows that an asteroid believed to have smacked Earth some 66 million years ago likely caused a global firestorm that led to extensive plant and animal extinctions. Credit: Illustration courtesy NASA/JPL.

A new look at conditions after a Manhattan-sized asteroid slammed into a region of Mexico in the dinosaur days indicates the event could have triggered a global firestorm that would have burned every twig, bush and tree on Earth and led to the extinction of 80 percent of all Earth's species, says a new University of Colorado Boulder study.

Led by Douglas Robertson of the Cooperative Institute for Research in Environmental Sciences, or CIRES, the team used models that show the collision would have vaporized huge amounts of rock that were then blown high above Earth's atmosphere. The re-entering ejected material would have heated the upper atmosphere enough to glow red for several hours at roughly 2,700 degrees Fahrenheit -- about the temperature of an oven broiler element -- killing every living thing not sheltered underground or underwater.

The CU-led team developed an alternate explanation for the fact that there is little charcoal found at the Cretaceous-Paleogene, or K-Pg, boundary some 66 million years ago when the asteroid struck Earth and the cataclysmic fires are believed to have occurred. The CU researchers found that similar studies had corrected their data for changing sedimentation rates. When the charcoal data were corrected for the same changing sedimentation rates they show an excess of charcoal, not a deficiency, Robertson said.

"Our data show the conditions back then are consistent with widespread fires across the planet," said Robertson, a research scientist at CIRES, which is a joint institute of CU-Boulder and the National Oceanic and Atmospheric Administration. "Those conditions resulted in 100 percent extinction rates for about 80 percent of all life on Earth."

A paper on the subject was published online this week in the Journal of Geophysical Research-Biogeosciences, a publication of the American Geophysical Union. Co-authors on the study include CIRES Interim Director William Lewis, CU Professor Brian Toon of the atmospheric and oceanic sciences department and the Laboratory for Atmospheric and Space Physics and Peter Sheehan of the Milwaukee Public Museum in Wisconsin.

Geological evidence indicates the asteroid collided with Earth about 66 million years ago and carved the Chicxulub crater in Mexico's Yucatan Peninsula that is more than 110 miles in diameter. In 2010, experts from 33 institutions worldwide issued a report that concluded the impact at Chicxulub triggered mass extinctions, including dinosaurs, at the K-Pg boundary.

The conditions leading to the global firestorm were set up by the vaporization of rock following the impact, which condensed into sand-grain-sized spheres as they rose above the atmosphere. As the ejected material re-entered Earth's atmosphere, it dumped enough heat in the upper atmosphere to trigger an infrared "heat pulse" so hot it caused the sky to glow red for several hours, even though part of the radiation was blocked from Earth by the falling material, he said.

But there was enough infrared radiation from the upper atmosphere that reached Earth's surface to create searing conditions that likely ignited tinder, including dead leaves and pine needles. If a person was on Earth back then, it would have been like sitting in a broiler oven for two or three hours, said Robertson.

The amount of energy created by the infrared radiation the day of the asteroid-Earth collision is mind-boggling, said Robertson. "It's likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth."

A 1-megaton hydrogen bomb has about the same explosive power as 80 Hiroshima-type nuclear bombs, he said. The asteroid-Earth collision is thought to have generated about 100 million megatons of energy, said Robertson.

Some researchers have suggested that a layer of soot found at the K-Pg boundary layer roughly 66 million years ago was created by the impact itself. But Robertson and his colleagues calculated that the amount of soot was too high to have been created during the massive impact event and was consistent with the amount that would be expected from global fires.

.


Related Links
University of Colorado at Boulder
Asteroid and Comet Impact Danger To Earth - News and Science






Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks
del.icio.usdel.icio.us DiggDigg RedditReddit GoogleGoogle




Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News





DEEP IMPACT
Fires After The Asteroid Impact Probably Caused The K-Pg Extinction
London, UK (SPX) Mar 28, 2013
About 66 million years ago a mountain-sized asteroid hit what is now the Yucatan in Mexico at exactly the time of the Cretaceous-Paleogene (K-Pg) mass extinction. Evidence for the asteroid impact comes from sediments in the K-Pg boundary layer, but the details of the event, including what precisely caused the mass extinction, are still being debated. Some scientists have hypothesized that ... read more


DEEP IMPACT
Pre-existing mineralogy may survive lunar impacts

Lunar cycle determines hunting behaviour of nocturnal gulls

Ultraviolet spectrograph observes mercury and hydrogen in GRAIL impact plumes

NASA's LRO Sees GRAIL's Explosive Farewell

DEEP IMPACT
BusinessCom Networks Connects Mars 2013

SwRI study finds liquid water flowing above and below frozen Alaskan sand dunes, hints of a wetter Mars

Opportunity Moves Into Place for Quiet Period of Operations

Measuring Mars: The MAVEN Magnetometer

DEEP IMPACT
India doing excellent in space programmes: Sunita Williams

Miners shoot for the stars in tech race

Space Innovation Center Will Help Govt Agencies Launch Future Space Missions

The Future of Exploration Starts With 3-D Printing

DEEP IMPACT
Shenzhou's Shadow Crew

Shenzhou 10 sent to launch site

China's Next Women Astronauts

Shenzhou 10 - Next Stop: Jiuquan

DEEP IMPACT
Alpha Magnetic Spectrometer Team Publishes First Findings

New crew takes express ride to space station

Soyuz Docks At Space Station Four Orbits After Launch

Three astronauts blast off on express ride to ISS

DEEP IMPACT
Future Looks Bright for Private US Space Ventures

Europe's next ATV resupply spacecraft enters final preparatio?ns for its Ariane 5 launch

ILS Proton Launches Satmex 8 Satellite for Satmex

When quality counts: Arianespace reaffirms its North American market presence

DEEP IMPACT
The Great Exoplanet Debate

Astronomers Detect Water in Atmosphere of Distant Planet

Distant planetary system is a super-sized solar system

Water signature in distant planet shows clues to its formation

DEEP IMPACT
CO2 could produce valuable chemical cheaply

Catalyst in a teacup: New approach to chemical reduction

Lasers could yield particle research tool

Paint-on plastic electronics: Aligning polymers for high performance




The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement