Many scientists believe that the dinosaurs died off when an asteroid struck the Earth 65 million years ago near what is now the Yucatan Peninsula. The impact ejected enough debris into the Earth's atmosphere to blot out sunlight and cool the Earth dramatically, so the thinking goes.
Now planetary geologist Buck Sharpton proposes an additional factor that might have wiped out the dinosaurs. Based on minerals found at the Chicxulub (pronounced "cheek shoo loob") crater, they claim that the impact may have kicked up sulfuric compounds and carbon dioxide into the atmosphere. The sulfuric compounds would have been poisonous and caustic, the researchers assert, while the carbon dioxide could have asphyxiated the dinosaurs.
In a related development, another group of scientists claims it has determined that Chicxulub Crater was indeed created by an asteroid, while the much older Sudbury Crater was formed by a faster-moving comet.
How outer space effects life on Earth is a major focus of astrobiology.
Jan 10, 2005 | TECHNOLOGIES
NASA Uses High-Tech X-Ray Equipment to Examine Dinosaur Skull
(NASA) - As NASA charts a bold new course into the future, the space agency is briefly taking a step back in time to examine life's past.
Mar 12, 2003 | SCIENCE
Argument over Dinosaur Demise Continues
(NYTimes.com) - Scientists argue over the potential links between asteroid impacts, volcanic activity and the end of the dinosaurs.
Sep 23, 2002 | SCIENCE
Rings Around the Earth: a Clue to Climate Change?
(Sandia National Labs) - An asteroid impact may have formed temporary rings around Earth, much like the rings of Saturn.
Aug 27, 2002 | SCIENCE
Dino-Killer Asteroid Triggered Huge Tsunamis
(Discovery) - Ancient landslides along the Pacific Coast tell of a 65-million-year-old asteroid impact.
Jul 25, 2002 | SCIENCE
Solar System's Path May Have Spurred Ice Ages
(Space.com) - Our solar system's orbit through the galaxy may have exposed it periodically to cosmic rays which altered Earth's climate.
Jul 23, 2002 | SCIENCE
The Earth is a Tough Place
(Space.com) - At a conference in Australia, astrobiologists turned their attention to geology: the early Earth, evidence of asteroid impacts, and deadly super-volcanoes
Jun 29, 2001 | SCIENCE
Mercury Accused of Dislodging Asteroid that Doomed Dinosaurs
(Space.com) - A shift in the orbit of Mercury may have perturbed the asteroid belt, nudging an asteroid toward Earth.
Jun 15, 2001 | SCIENCE
Do We Know What Killed the Dinosaurs?
(NASA Astrobiology Institute) - Exactly how a single asteroid impact caused so much devastation remains a matter of debate.
Mar 08, 2001 | SCIENCE
Dinosaurs may have died off quickly
(BBC) - New research supports the idea that an asteroid or comet impact wiped out the dinosaurs.
Nov 22, 2000 | SCIENCE
Scientists simulate how an asteroid dug a crater
(Space.com) - The impact in the Yucatan peninsula 65 million years ago may have wiped out the dinosaurs.
May 31, 2000 | SCIENCE
Evidence that dinosaurs died quickly from asteroid impact
(CBC) - A new study of the fossil record suggests that dinosaurs became extinct abruptly. The finding supports the theory that they were wiped out by an asteroid.
Sep 02, 1999 | SCIENCE
Dinosaurs may have been thriving just before asteroid impact
(Chicago Tribune) - Scientists have debated whether dinosaurs were wiped out by an asteroid, or whether they were already in decline when the asteroid hit. Rich fossil finds in South America suggest they were still going strong shortly before the catastrophe.
Aug 28, 1999 | SCIENCE
Debate: were mass extinctions caused by impacts or volcanoes?
(New Scientist) - In this book review, a scientist discusses possible causes of mass extinctions 65 million years ago, including a comet or asteroid impact, and an increase in volcanic activity.
