Level 1 — Absolute Beginner
A long time ago, big rocks from space called asteroids hit the young Earth many times.
Scientists built computer models to study what happened after these hits.
The hits cracked open the ground and let hot water flow through it.
Scientists think this hot water may have helped the first life begin on Earth.
- asteroid
- a large rocky object that travels through space
- impact
- the act of one object hitting another with force
- crust
- the hard outer layer of a planet
- hydrothermal
- having to do with hot water underground
- model
- a computer program that represents how something works
- ancient
- very old, from a long time ago
- environment
- the natural surroundings where living things exist
- scientist
- a person who studies the natural world
Level 2 — Elementary
Scientists at the Southwest Research Institute built detailed computer models of how asteroid impacts affected the very early Earth, billions of years ago.
They found that the impacts cracked open the planet's crust, making it easier for water to soak deep underground and get heated, creating large hydrothermal systems.
Some of these hot-water systems may have covered huge areas and lasted for thousands, or even millions, of years, giving simple molecules time to combine into more complex ones.
The researchers estimate that a single impact from that early bombardment period could have created up to one hundred times more hydrothermal activity than exists in Yellowstone National Park today.
- bombardment
- a period of repeated impacts or strikes, such as by asteroids
- soak
- to pass slowly into or through something, like water into rock
- molecule
- a small group of atoms bonded together, a basic building block of matter
- complex
- made of many connected parts; not simple
- estimate
- to make an approximate calculation or judgment
- researcher
- a person who investigates a subject to discover new information
- billion
- a thousand million
- planet
- a large round object in space that orbits a star
Level 3 — Intermediate
A new study from the Southwest Research Institute, published in the journal AGU Advances, presents the first comprehensive attempt to quantify how asteroid impacts generated crustal permeability across the early Earth, offering fresh insight into where life's earliest chemistry might have taken hold.
Using a shock physics code that simulates how impacts fracture rock and create porous pathways underground, the research team modeled the cumulative effect of repeated asteroid strikes during the planet's earliest history, roughly 4.3 billion years ago.
The results suggest that the upper eight kilometers of Earth's crust was likely highly permeable at that time, allowing water to circulate and become heated into vast hydrothermal systems, some of which may have remained active until as recently as 3.5 billion years ago.
According to the researchers, individual impacts from this bombardment period could have generated hydrothermal activity roughly one hundred times greater than what is found in Yellowstone National Park today, turning what looks like pure destruction into environments potentially hospitable to the chemistry of life.
- quantify
- to express or measure something as a definite amount
- crustal permeability
- how easily fluids like water can move through a planet's outer rock layer
- shock physics
- the study of how materials respond to sudden, intense force
- porous
- full of tiny holes that allow liquid or air to pass through
- cumulative
- increasing or building up as more things are added over time
- circulate
- to move continuously through a system or area
- hospitable
- favorable or welcoming to living things
- comprehensive
- complete and including everything necessary
Level 4 — Advanced
Researchers at the Southwest Research Institute have published, in the journal AGU Advances, what they describe as the first comprehensive quantification of impact-generated crustal permeability on the early Earth, a study that reframes the planet's most violent bombardment period as a plausible incubator for prebiotic chemistry rather than merely an agent of destruction.
The team deployed a shock physics code capable of modeling how hypervelocity impacts fracture competent rock and generate interconnected porosity, then applied a bombardment history model to infer the cumulative effect of recurring asteroid strikes roughly 4.3 billion years ago, during the Hadean eon.
Their results indicate that the upper eight-kilometer shell of Earth's crust was likely rendered pervasively permeable during this period, with substantial portions of that volume potentially remaining permeable until as recently as 3.5 billion years ago, sustaining hydrothermal circulation on a scale that dwarfs any comparable system operating today.
The authors estimate that individual impacts from this era could have driven hydrothermal activity roughly a hundredfold greater than that of modern Yellowstone, a finding that lends fresh, quantitative weight to the long-standing hypothesis that impact-generated hydrothermal systems, rather than surface oceans alone, may have furnished the sustained thermal and chemical gradients necessary for life's earliest emergence.
- incubator
- an environment that promotes the development of something
- prebiotic
- relating to the chemical conditions that existed before life began
- hypervelocity
- extremely high speed, as with an impacting object
- interconnected porosity
- a network of linked tiny holes or spaces within a material
- Hadean eon
- the earliest geological time period of Earth's history
- pervasively
- spread throughout every part of something
- hundredfold
- one hundred times as much or as many
- thermal and chemical gradients
- gradual differences in heat and chemical concentration across a space
