Simple version
Chicxulub is the impact crater linked to the extinction of the non bird dinosaurs around 66 million years ago.
It lies partly under the Yucatán Peninsula in Mexico and partly under the Gulf of Mexico. The object that hit Earth was probably around 10 kilometres wide. That sounds small compared with Earth, but at asteroid impact speeds it was enough to change the planet.
What happened on impact
The impact released an enormous amount of energy. It blasted rock into the atmosphere, created earthquakes, triggered tsunamis and caused fires.
But the long term danger was not only the blast. Dust, soot and sulphur compounds were thrown into the atmosphere. Sunlight was blocked. Global temperatures dropped. Plants struggled. Food chains collapsed.
The iridium layer
One of the key pieces of evidence was a thin global layer of clay enriched with iridium. Iridium is rare in Earth's crust but more common in asteroids.
Scientists found this layer at the boundary between rocks from the Cretaceous period and rocks after it. That boundary matched the timing of the dinosaur extinction.
How we found the crater
The impact idea was controversial at first. Later, geologists identified the buried Chicxulub crater using gravity data, drilling evidence and shocked minerals.
The crater connected the global iridium evidence to a real impact site.
Common mistake
A common mistake is thinking the asteroid only killed dinosaurs by hitting them directly. Most animals were not killed by the rock itself.
The real disaster was global environmental collapse after the impact.
AwareSTEM link
This page is planetary detective work. It connects geology, chemistry, fossils, astronomy, climate and survival.
It also links directly to planetary defence today. Learning what happened in the past helps us think about future risk.
What learners should notice
The dinosaur extinction was not only a dramatic impact. It was a systems collapse.
The rock hit one place, but the consequences spread through atmosphere, climate and food chains.
Build the understanding
Connect impact, dust and sulphur, sunlight loss, plant death, food chain collapse and extinction.
This helps learners see why global systems matter.
AwareSTEM activity idea
Make a cause and effect chain on paper. Start with asteroid impact. End with loss of species. Add at least six steps between.
Quick recap
Chicxulub Crater sits inside the The Great Extinction part of The Story of Everything. The main point is this: the impact, the evidence, the iridium layer, and how we found it.
By the end of this page, the learner should be able to explain the idea in plain English, connect it back to the timeline, and say why it matters beyond a school-style fact.
Key words to know
Use these as anchor words while learning this topic: Chicxulub Crater, The Great Extinction, evidence, time, change, system, signal, scale and connection.
The aim is not to memorise every word. The aim is to build a small vocabulary that helps the learner explain the idea clearly to someone else.
Question to ask
Ask: what does chicxulub crater change in the bigger story?
A good answer should not stop at one fact. It should explain what came before, what changed, and how that change affected the next part of the timeline.