Buffer
Tags
bio/astro
cegep/3
Word count
294 words
Reading time
2 minutes
- nebula: galactic cloud
- solar system: stars and planets that orbit it
- astrobiology: study of life in the universe
2025-08-22
- Criteria:
- Habitable zone
- Adequate temperature
- Liquid water
- Eccentricity of planet not too high
2025-08-27
source of elements
- Big Bang nucleosynthesis
- Matter made from extremely intense light within the first 5 minutes => proton (hydrogen), electron & neutron
- Nuclear fusion: collision of hydrogen within the first few hours => helium
- Low mass star (red giant)
- CNO cycle => helium
- High mass star (supergiant)
- Helium capture => elements until iron
- Star explodes to become neutron star => gold & uranium
- White dwarf supernovae => iron-group elements
- Radioactive decay => radioactive elements
- Neutron star
- => neutron
- R-process: merge of neutron stars => radioactive elements
- Cosmic ray spallation => beryllium & bore
- Human-made => synthetic elements like technetium
2025-08-29
escape speed
Minimum speed needed for an object to escape the gravitational field of another object
- Proof
[!example]+ Determine the escape speed of the moon.
Kepler's Laws
First Law
The orbit of planets around the sun is an ellipse.
[!abstract] eccentricity
Measure of how ellipse-like the orbit is
Second Law
A planet sweeps out equal areas of its orbit in equal times.Aka.
conservation of angular momentum
Third Law
More distant planets orbit at slower speeds, obeying the relationship
Therefore, to determine the mass of a planet: