Level 1 — Absolute Beginner
A huge rock from space hit Earth long ago. It killed almost all the dinosaurs. Scientists now know more about this rock.
The rock was a rare kind of meteorite. Scientists call it a CO chondrite. Only a few space rocks like this have ever been found.
Scientists studied nickel in the rock. This helped them learn where the rock came from. It came from far away in space.
The rock was about 10 to 15 kilometers wide. It hit Earth 66 million years ago. About 75 percent of all animals died.
- space rock
- a large rock that travels through space, like an asteroid
- dinosaur
- a large reptile that lived millions of years ago
- rare
- not common; hard to find
- meteorite
- a piece of rock from space that lands on Earth
- nickel
- a type of metal found in rocks and meteorites
- million
- a very large number, one thousand thousand
- wide
- the distance across something
- extinct
- no longer existing
Level 2 — Elementary
Scientists have identified the exact type of space rock that wiped out the dinosaurs 66 million years ago. The asteroid was an exceptionally rare type of meteorite called a CO chondrite.
Researchers from the University of British Columbia, along with teams in Paris, Brussels, and Vienna, studied nickel isotopes preserved in material left behind by the impact. This let them trace the asteroid's likely origin to a distant part of the solar system.
Carbonaceous chondrites make up only about 5 percent of meteorites found on Earth, and CO chondrites are just a small slice of that group. They are considered some of the most primitive materials left over from the early solar system.
The asteroid, roughly 10 to 15 kilometers across, triggered the extinction of about 75 percent of all species on Earth, including every dinosaur except birds. Its unusual chemistry suggests fine dust it kicked into the atmosphere, not sulfur from inside the rock, may have caused the deadliest damage.
- exceptionally
- to an unusually great extent
- isotope
- a version of a chemical element with a different number of neutrons
- preserved
- kept in its original state without damage
- trace
- to find the origin or source of something
- carbonaceous
- containing carbon
- primitive
- existing in an early, simple, or original state
- atmosphere
- the layer of gases surrounding a planet
- chemistry
- the substances and properties that make up something
Level 3 — Intermediate
Scientists have pinpointed the precise nature of the asteroid that ended the age of dinosaurs 66 million years ago, identifying it as an exceptionally rare CO chondrite, a class of meteorite that accounts for only a sliver of the material that regularly falls to Earth. Researchers from the University of British Columbia, working alongside colleagues in Paris, Brussels, and Vienna, reached the conclusion by analyzing nickel isotopes preserved in sediment layers laid down at the Cretaceous Paleogene boundary.
Carbonaceous chondrites represent only about 5 percent of meteorites sampled on Earth, and CO chondrites, sometimes called Ornans class chondrites, make up a small fraction of even that limited group. Considered among the most primitive and least altered materials remaining from the solar system's formation, their presence at the impact site points to an origin either in a distant, debris filled region of the outer solar system or in the outer reaches of the asteroid belt near Jupiter.
The impactor itself measured an estimated 10 to 15 kilometers across, roughly six miles, and its arrival triggered a mass extinction that eliminated approximately 75 percent of all species then living, including every non avian dinosaur lineage. What sets this new analysis apart is its focus on the asteroid's unusual chemistry, which suggests that fine, planet cooling dust ejected into the atmosphere, rather than sulfur released from within the asteroid, may have delivered the extinction event's most lethal blow.
The finding refines decades of research into the Chicxulub impact, offering scientists a more precise chemical fingerprint of an object that, despite its outsized influence on the history of life on Earth, left behind only fragmentary physical evidence for researchers to reconstruct.
- pinpoint
- to identify something precisely
- sliver
- a small, thin piece or portion of something
- sediment
- material deposited by water, wind, or ice
- boundary
- a line marking the limits of an area, or the transition between two periods
- impactor
- an object that strikes another object, such as an asteroid hitting a planet
- lineage
- a sequence of species or organisms descended from a common ancestor
- lethal
- capable of causing death
- fingerprint
- a distinctive identifying characteristic or pattern
Level 4 — Advanced
A team of researchers has pinpointed the precise mineralogical identity of the asteroid responsible for terminating the age of dinosaurs 66 million years ago, classifying it as an exceptionally rare CO chondrite, a meteorite category that constitutes only a marginal fraction of the material that ordinarily falls to Earth. Scientists from the University of British Columbia, in collaboration with counterparts in Paris, Brussels, and Vienna, arrived at this conclusion through meticulous analysis of nickel isotope signatures preserved within sediment deposited at the Cretaceous Paleogene boundary.
Carbonaceous chondrites constitute a mere five percent of meteorites sampled on Earth, and CO, or Ornans class, chondrites represent a comparatively minuscule subset of even that limited population, regarded as among the most primitive and least thermally altered relics surviving from the solar system's formative period. Their detection at the impact horizon implicates an origin either within a debris strewn region of the distant outer solar system or in the outer asteroid belt proximate to Jupiter.
The impactor itself is estimated to have spanned some 10 to 15 kilometers, and its collision precipitated a mass extinction event that extinguished approximately three quarters of contemporaneous species, including every non avian dinosaur lineage. The analysis's distinguishing contribution lies in its interrogation of the asteroid's anomalous chemical composition, which implies that fine, planet cooling particulate matter ejected into the upper atmosphere, rather than sulfur liberated from within the impactor, may have inflicted the extinction event's most lethal consequences.
This refinement to decades of Chicxulub scholarship furnishes researchers with a substantially more precise chemical fingerprint of an object whose disproportionate influence over the trajectory of terrestrial life stands in stark contrast to the fragmentary physical evidence it left behind for subsequent reconstruction.
- mineralogical
- relating to the study or composition of minerals
- marginal
- relatively small or insignificant in amount
- meticulous
- showing great attention to detail; very careful and precise
- thermally
- relating to heat
- horizon
- in geology, a distinct layer within rock or sediment
- proximate
- nearest or next in a series; close to
- anomalous
- deviating from what is standard, normal, or expected
- disproportionate
- too large or too small in relation to something else
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