PLanets Flashcards
What is a planet?
A celestial body that:
- Is in orbit around the sun
- Has enough mass for its self- gravity to overcome rigid body forces, to achieve hydrostatic equilibrium (almost round)
- Has cleared the neighbourhood around it’s orbit
What is a Dwarf planet?
A celestial body that:
- Is in orbit around the sun
-Has enough mass for its self- gravity to overcome rigid body forces, to achieve hydrostatic equilibrium (almost round)
- Has no cleared the neighbourhood around it’s orbit
- Is not a satellite
What do terrestrial planets mainly consist of?
Rocky matter with a molten core
What do Jovian planets mainly consist of?
Gas and liquid with a rock core
What do all Jovian planets have?
Ring systems
Which planet doesn’t have a nearly circular orbit?
Pluto
What planets orbits are on an inclination the plane Earth orbits on?
Pluto and Mercury
What is the hill radius?
The distance away from a planet orbiting a star that you can expect to find a moon.
What is the Maxwell distribution?
In a gas there is a wide range of molecular speeds
Atmosphere depends on what four factors?
-Escape velocity
- Weight of molecules
- The tail of distribution
- Temperature in higher layer of atmosphere
What do molecular speeds depend on?
Temperature
What did the modern evolutionary Theory show?
Weizacker’s analysis of a rotating gas condensing around a protosun showed that the gas would form eddies, with larger eddies further from the centre
How does the Extrasolar planet search Astronomical method work?
The presence of a planet around a star results in a to and from motion for the star, which reveals the radial velocity of the star.
What are three methods of Extrasolar planet search?
- Astronomical method
- The Doppler (radial velocity) method
- The transit Photometry method
How does the transit photometry method work in Extrasolar planet Search?
When a planet passes directly between it’s star and an observer’s line of sight, it blocks out a portion of the star’s light
