Let's start simple with the Hadean Eon. I have included terms at the end of each section for easy clarification :3
A brand new planet
The Earth formed from accretion. Gas and dust were pulled in from a solar nebula, which was collapsing due to its extreme gravity. Over time, collisions and merging of small particles created a planetesimal with a molten surface.
This planetesimal collided with other planetesimals, creating the protoplanet Earth. Protoplanet Earth's orbital path was not clear, similar to Pluto's. It was bombarded by many protoplanets, rocks, and planetesimals. These impacts generated large amounts of heat, and more heat was added by the radioactive decay of short-lifetime elements
The surface of the protoplanet Earth was so hot that all the rock melted into magma
The Hadean is estimated to have lasted from 4.6 GA to 4.031 Ga
Terms:
Ga: An abbreviation for billion
Accretion: When gravity pulls small particles together and creates a planetesimal
Planetesimals: Small planet-like objects found in planetary rings
Protoplanet: A large body of matter that orbits a star and is developing to be a planet
Short-lifetime elements: Elements that decay quickly
Earth's layers
All of the matter that formed planet Earth were elements produced from exploding stars. All these elements were homogeneously mixed. However, the elements started to separate from a process called differentiation
Elements like iron and nickel had the highest density. They were attracted to each other, and gravity pulled them down into the center of the planet. This is what we call the inner core. Iron and nickel solidified and heated by extreme pressure and radioactive decay of isotopes
Elements like silicon, oxygen, and magnesium reside close to the surface, making the mantle and crust
Differentiation took place over several million years
Terms:
Differentiation: The separation of something
Homogeneous: A mixture having equal parts of all materials
Isotope: A form of an element with a different number of neutrons
Earth's atmosphere
Large volcanoes had formed on the surface from the crust giving way to convection. They spewed lava and gases, establishing a thin atmosphere along with gases from space rocks
It is thought that the atmosphere was composed of water, methane, ammonia, carbon dioxide, sulfur dioxide, hydrogen, and nitrogen.
Carbon dioxide was present in large amounts, like on Mars
Oxygen did not exist in the atmosphere for two billion years
The atmosphere took on a reddish or orangey color from the mix of greenhouse gases
Terms:
Convection: Hot gases rise and cold gases sink, creating a cycle of heat transfer
Greenhouse gases: Gases that trap heat and warm the Earth
Formation of the moon
According to the widely accepted Giant-Impact Hypothesis, a protoplanet the size of Mars, called Theia, collided with the Earth. The two celestial bodies merged, adding to Earth's mass. Ejected particles circled the Earth like rings for about 2,000 years before condensing into the moon. The moon was once closer to the Earth, looking massive in the night sky
Earth's layers pt 2
After the Giant-Impact Hypothesis with the protoplanet Theia, the Earth was once again molten. As the Earth cooled, crystals of magnesium silicate, called olivine, formed. Olivine crystals sank into the magma, growing into bigger crystals. This formed into a green igneous rock called Dunite. Dunite is the predominant rock of the lower mantle
Pyroxene, a rock made of silicate, formed and mixed with the olivine. This made peridotite, the most common rock in the upper mantle
A pyroxene melted, lighter magma rose to the surface and spewed out of volcanoes or rifts. This formed basalt, making the first crust of the Earth an ashy wasteland
Terms:
Silicate: Silcon and oxygen compound
Igneous: A rock formed by the cooling of magma or lava
Oceans?
Small gemstones called Zircons are made up of a uranium-238 core and oxygen. The presence of oxygen isotope 180 suggests that the crystals were most likely formed in water. The isotope uranium-238 decays into lead-206 over a half-life of 4.47 billion years. With the crystal formed in water and the uranium isotope core, there was water somewhere on Earth
Continents had not yet formed, but in the sea of basalt, there were many volcanoes. Through a process called outgassing, water vapor collected in the atmosphere, which condensed and fell as rain. This helped fill basins
The largest event contributing to the majority of water on Earth today is the Late Heavy Bombardment. This event took place at the end of the Hadean and into the Archeon, lasting from 4.1 to 3.8 billion years. Earth and the Moon were struck by comets and asteroids for 300 million years. The ice from the comets melted from the intense heat of the collision, forming water
Terms:
Outgassing: A release of gases from Earth's interior through eruptions, vents, and fissures
Passage of time
The Earth rotated faster than it does today in the Hadean, leading to 6 hours days. If you stayed 24 hours, one day in the present would be four in the Hadean
you are looking up from the bottom of a warm little pond, ~4.1 billion years ago.
microscopic proto-lifeforms float and replicate about, inseminating themselves into every crease of the tenantable basin.
they are malleable and fleeting entities for now-but as their machinery slowly amasses in complexity and stability, their furious propagation will carve out the mountains & fill the seas with evermore squirming selves.
Scientists agreed the rocky outcrops in a remote part of Quebec, Canada, were ancient. But were they really Earth’s oldest? New research sug
A rocky outcrop in a remote corner of northern Quebec appears serene in its eerie isolation on the eastern shore of Canada’s Hudson Bay.
But over the past two decades, this exposed remnant of ancient ocean floor, known as the Nuvvuagittuq Greenstone Belt, has been a heated scientific battleground in the quest to identify Earth’s oldest rock.
New research suggests that the geological site harbors the oldest known surviving fragments of Earth’s crust, dating back to 4.16 billion years ago. It’s the only rock determined to be from the first of four geological eons in our planet’s history: the Hadean, which began 4.6 billion years ago when the world was hot, turbulent and hell-like.
Approximately 4.5 billion to 4 billion years ago, the earth we know and love was an unassuming ball of rock and fire orbiting our young star. With harsh volcanic activity and frequent celestial impacts, it's difficult to imagine this hellish world would ever become habitable for life.
This time period is known as the Hadean Eon, named after the Greek god of the underworld, Hades. During this time of around half a billion years, the atmosphere would form, rich with CO2 and methane. A smaller planet known as Theia slammed into the earth and formed the moon. As time went on, the chaos started to die down and the planet began to cool.
This artistic rendition takes you back ~4.1 billion years into our planetary past when the Earth was facing turbulent seismic activity and mass extraterrestrial bombardment.
One particular asteroid is seen hurling towards the nascent planet with great rigor, threatening to desecrate some of the newly formed landmasses. However, a spark of potential has hitched a ride on board—because not only is this asteroid water-rich, it also contains all five nucelobases necessary for DNA and RNA, reflecting recent findings on asteroids Bennu and Ryugu. Once it strikes the Earth, the impact crater will become a basin for a warm little pond, creating a cradle for these newly delivered biomolecules to amass in complexity.
This was a really fun one—depicting a late Hadean earth based on updated research whilst also taking some liberties with the color palette was enjoyable!
⚠️ As always: This is a speculative artistic rendition. artistic license & exaggeration applies for visual discernment and does not always reflect accuracy.
