Lecture 2 - Week 1 - Origin of the Earth Flashcards
Describe Hubble’s Law in 6 words?
Objects in space are moving apart.
What is the evidence of objects moving apart?
Redshift
Hubble’s Law supports the Big Bang because…
If objects are moving apart, they
must have started together at a
single point.
Big Bang Nucleosynthesis is considered responsible for…
The creating of some forms of hydrogen, helium and some lithium.
Stellar Nucleosynthesis creates elements by…
The super heating of elements that makes up the star.
In Stellar Nucleosynthesis, combining nucleons of this gas [ __________ ] with other elements (carbon, oxygen, neon, etc.) = magnesium, silicon, sulphur, calcium, iron, etc.
Helium
_________ are stellar nurseries. Stars form by collapse of parts of an individual __________.
Nebulae. Nebula.
Basic nucleosynthesis is…
The creation of nuclei from existing nucleons
Galactic Nucleosynthesis is when…
Cosmic rays collide with heavier atoms and create new forms of matter (this occurred in the moments after the BB)
When did the big bang occur?
How long after did the first stars form?
When did our solar system form?
- Big bang: 13.8 billion years ago
- First stars formed 200-400 million years after the BB
- Our solar system forms 9 billion years after BB
How do stars form from nebulae?
- Clouds are very large, very cold, very dense
- Combination means that clumps tend to collapse under own weight (gravity)
- Clumps = cores where new stars are forming
- Collapse (shrink)> higher density> higher gravity> collapse> higher density….and so on
- Eventually core ignites
What is an a accretionary disk?
A rotating disk of matter formed by accretion around a massive body due to gravity.
What are two formations in intermediary stage between the accretionary disk and the formation of a solar system?
The core of the disk becomes a protostar. Around the protostar is a disk of dust, gas, and other elemental matter known as a protoplanetary disk.
The matter in the ____________ sticks to each other to form clumps known as ____________.
Protoplanetary disk. Planetismals.
Eventually, after planetismals keep accreting material due to gravity, they become ____________.
Protoplanets.
