Life in the Cosmos Flashcards
Lectures 1-3 (29 cards)
How long ago was the big bang?
17 billion years ago
What element is primordial?
Hydrogen
What are the two places where the build of nuclei can take place?
- Nuclear fusion in the Earth
- In the cores of stars
What does it mean by exothermic?
More energy is produced that needed.
What does the abundance of elements formed in steller cores depend on?
The mass
What does it mean when a star is endothermic?
A star produces less energy than it is receiving
How does a star’s supernova explosion work?
- The outer layers of the star collapse until it reaches the iron core
- The core then explodes, dispersing heavier elements back into space.
How are complex molecules identified?
Through the radiation that they emit
How are proto-stars and proto-planetary disks identified?
Through microwave and infra-red emissions.
How long does disk formation usually last?
30 million years
What is the 1st stage of planetory formation?
Condensation
What happens during the 1st stage of planetory formation? (Condensation)
Dust molecules act as condensation centres which other dust can stick to
What is the 2nd stage of planetary formation?
Accretion
What is the 3rd stage of planetary formation?
Coalescence
How old is the oldest material dated in the solar system?
4.5 billion years
Between what two years was the Hadean Era?
3.8 to 4 billion years
Give two examples of elements that were driven out of the atmosphere during the Hadean Era
Carbon Dioxide and Water
What was going on during the Hadean Era?
- The earth was extremely hot and volcanically active
- Underwent frequent collisions from planetesimals
What era was life first clearly discovered on Earth?
The Archean Era
What 3 factors describe early life forms on Earth?
- Must replicate
- Must mutate
- Must evolve
What chemistry are all life forms on Earth?
Carbon
What type of acid is the build blocks for protein?
Amino
How long ago was the first life form discovered?
3.5 billion years ago
The early atmosphere was mostly composed of which 5 elements?
Nitrogen, Carbon Dioxide, Water, Methane, Hydrogen