Podcast
Questions and Answers
A menacing asteroid, some six miles wide, triggered Earth's last mass ______.
A menacing asteroid, some six miles wide, triggered Earth's last mass ______.
extinction
This behemoth object came from beyond the gas giant ______.
This behemoth object came from beyond the gas giant ______.
Jupiter
Today this impact zone is called the ______ Crater.
Today this impact zone is called the ______ Crater.
Chicxulub
Around 70 percent of Earth's species ______ due to the impact.
Around 70 percent of Earth's species ______ due to the impact.
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A thin layer of sediment from this event is called the ______ boundary.
A thin layer of sediment from this event is called the ______ boundary.
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The composition of the asteroid that impacted at Chicxulub is the same as that of ______ meteorites.
The composition of the asteroid that impacted at Chicxulub is the same as that of ______ meteorites.
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Only three or so laboratories globally, including at the University of ______, can conduct this ultra-specialized research.
Only three or so laboratories globally, including at the University of ______, can conduct this ultra-specialized research.
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A 'dinosaur-killing' impact from a rock perhaps a half-mile across or larger happens on ______ timescales.
A 'dinosaur-killing' impact from a rock perhaps a half-mile across or larger happens on ______ timescales.
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NASA has successfully tested the first-ever endeavor to intentionally move an ______.
NASA has successfully tested the first-ever endeavor to intentionally move an ______.
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Impacts by objects around 460 feet in diameter occur every ______ to 20,000 years.
Impacts by objects around 460 feet in diameter occur every ______ to 20,000 years.
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Study Notes
Asteroid Impact and Mass Extinction
- A six-mile-wide asteroid caused Earth's last mass extinction approximately 66 million years ago.
- Originated from beyond Jupiter; identified as a C-type asteroid, consisting of dark, carbon-rich materials.
- Impact resulted in widespread debris across Earth, significantly altering the climate.
Chicxulub Crater
- The impact zone is known as the Chicxulub Crater, located beneath the Yucatan Peninsula.
- The asteroid struck in shallow water, launching vast amounts of pulverized rock into the atmosphere, leading to a "long, callous winter."
Environmental Effects
- The cooling climate caused a shutdown of photosynthesis, leading to a collapse of the food chain.
- An estimated 70% of Earth's species perished, although some dinosaurs managed to survive.
- A distinct sediment layer, named the K-Pg boundary, is present globally, marking the event.
Ruthenium Evidence
- Ruthenium, a rare element in Earth's crust, is predominantly derived from the impactor and found in the K-Pg boundary layer.
- Ruthenium isotopes from this layer show similarity to carbon-rich meteorites, confirming the asteroid's origin.
- Composition analysis indicates a match with carbonaceous meteorites from the outer solar system.
Research Significance
- Prior studies suspected a C-type asteroid, but lacked ruthenium analysis.
- Technological advancements allowed for the precise measurement of ruthenium isotopes, conducted by only a few global laboratories.
Asteroid Dynamics
- C-type asteroids reside at the outskirts of the main asteroid belt, between Mars and Jupiter.
- The Chicxulub impactor was likely propelled toward Earth through asteroid collisions or sunlight exposure causing thermal energy release (Yarkovsky effect).
Frequency of Impacts
- "Dinosaur-killing" asteroid impacts (half-mile wide or larger) occur every 100 million years on average.
- Over 90% of threatening "planet-killer" asteroids have been identified, with no immediate threats projected for the next century.
- Smaller impacts (460 feet in diameter) are estimated to happen every 10,000 to 20,000 years, causing regional damage.
Asteroid Defense Initiatives
- NASA has conducted successful tests to intentionally redirect asteroids, a crucial skill for planetary defense.
- No warnings have been issued regarding imminent asteroid threats, but protocols are in place for potential notifications from authorities, including the White House.
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Description
This quiz explores the origins and impact of the asteroid that caused Earth's last mass extinction. Learn about the unique characteristics of C-type asteroids and how this catastrophic event shaped our planet. Test your knowledge on cosmic events and their implications for life on Earth.
