The Solar System Flashcards
Lectures 1-3 (46 cards)
Out of the 13 planetary bodies, how many are planets?
8
Out of the 13 planetary bodies, how many are dwarf planets?
5
What are the three factors that define a planet by the IAU?
- It must orbit the sun
- It must be large enough to take a spherical shape.
- It must have cleared it’s orbit of other planets
What are the four factors that define a dwarf planet by the IAU?
- It must orbit the sun
- It must be large enough to take on a spherical shape
- It has not cleared it’s orbit
- It is not a satellite
What are the two types of planets?
Terrestrial and Jovian
Which are the Terrestrial planets?
Mercury, Venus, Earth, Mars
Which are the Jovian planets?
Jupiter, Saturn, Uranus, Neptune
What three factors would define a terrestrial planet?
- High Density
- Solid Rocky Surface
- Metallic core
What factors would describe a Jovian planet?
- Low Density
- Gaseous
- Not defined surface
List the five official dwarf planets
- Ceres
- Pluto
- Eris
- Haumea
- Makemake
What are Kepler’s three laws?
- Planets orbit the sun in an ellipse with the Sun and the centre
- The line between the planet and the sun sweeps out an area at a constant rate
- The period of the orbit of a planet is proportional to a3/2 where a is the semi-major axis of the ellipse.
What is De Buffon’s Passing Star Model (Catastrophic Model)?
The theory that planets were formed by the sun pulling materials from another star close to it.
What are 3 examples of problems of De Buffon’s Passing Star Model?
- The material pulled from the sun would be very hot and unlikely to form planets.
- Circular orbits would be unlikely
- Does not explain varying properties of different planets
What is the Evolutionary model?
The sun and the planets are formed from a nebula of gas and dust
What is stage 1 of the evolutionary model/the solar nebula hypothesis?
The cloud of Gas and Dust
What happens at stage 1 of the evolutionary model/the solar nebula hypothesis (The cloud of gas and dust)
The sun and the planets are formed at the same time from rotating cloud of gas.
What is stage 2 of the evolutionary model/the solar nebula hypothesis?
Disc rotation
What are the 3 steps of stage in the evolutionary model/the solar nebula hypothesis (Disc Rotation)?
- As the clouds rotated, it became smaller.
- Gravity causes a concentration at the centre of the disc which became the sun.
- Further from the centre, dust and molecules of gas created other bodies by a process of accretion.
What is stage 3 of the evolutionary model/the solar nebula hypothesis?
The formation of planetesimals
What happens during stage 3 of the evolutionary model/the solar nebula hypothesis? (the formation of planetismals) (3 factors)
- The accretion bodies formed in Stage 3 are too small for gravity to be effective
- Clumps of matter acted as condensation nuclei
- Through electrostatic forces, the bodies started to coalesce and grow.
What is stage 4 of the evolutionary model/the solar nebula hypothesis?
The formation of protoplanets
What happens during stage 4 of the evolutionary model/the solar nebula hypothesis? (the formation of protoplanets) (2 points)
- At this point, clumps have coalesced into larger bodies (about 100km in diameter)
- Due to their size, they have a large gravitional attraction and collect other bodies effectively until they become planets.
What are the 2 successes of the evolutionary model/the solar nebula hypothesis?
- Explains the disc shape of a solar system
- Explain why everything rotates the same way
What two elements can small planets not capture?
Hydrogen and helium
