Hello everyone! This is my science blog because, well, I’m a nerd
I am a Biology Major looking to specifically go into the study of genetics, but I love all sciences and know things about majority of them. I’ve been doing a big research project recently so - I needed a place to yap about it
If you have any science related questions, I will be happy to answer them :3
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
