Topic 11 Flashcards
Name the 8 planetary bodies in order
- Merury
- Venus
- Earth
- Mars
- Jupiter
- Saturn
- Uranus
- Neptune
WHat are the inner 4 terrestrial planets and what are they made of?
-Mercury, Venus, Earth, Mars. Rocky with a core of iron
Do terrestrial planets have rings?
No
Which terrestrial planet does not have an atmosphere with large molecules
Mercury
WHich are the only 2 terrestrial planets with Moons
Earth and Mars
WHat are the outer 4 gas giant planets? What are they made of
Jupiter, saturn, Uranus, Neptune, they are gaseous with liquid interiors
What are 4 characteristics of gas giants
-have many moons
-relatively large diameter and mass
-atmosphere made predominantly of hydrogen and helium with some methane and ammonia
-all have rings
What are some key features of dwarf planets
-THey orbit around the Sun
-THey don’t satellite another planetary body
-Have a near spherical or consistent shape
-different to a normal planet due to size and eccentric orbit
What are the 4 closest dwarf planets
Pluto, Eres, Ceres, MakeMake
What is an asteroid?
iron and silicate based rocks, found inbetween Mars, and Jupiter in the Asteroid belt, with a diameter of less than 10km
What is a comet
dust, rock, and ice balls that come from the outer solar system and orbit the Sun,
as the comet approaches the Sun, water evaporates off along with other sublimed gases from the nucleus and produce the ‘coma’ around the nucleus, this is held by weak gravity.
Name the main components of a comet
Coma, Dust trail, ion tail, hydrogen cloud, nucleus
What is the dust trail?
the most prominent to the observer it is made of dust particles and gases from the interaction with radiation and pressure form the SUn
What is the ion tail
caused by ions from the solar wind, interacting with the particles of a comet to forma more coloured and straight tail
What is the hydrogen cloud
huge but very sparse envelope of neutral hydrogen
WHat is the coma
dense cloud of water, CO2, and other neutral gases sublimed from the nucleus
What is the nucleus
relatively solid and stable mostly ice and gas with a small amount of dust
What are the characteristics of the orbit of a comet
Comets orbit the Sun at a sharp incline to the ecliptic
-THey can have a prograde or retrograde motion
-Comets have high eccentricity and can be parabolic
WHat eventually happens to comets
Eventually comet will burn up, exhausting its materials and orbiting the SUn as a rock/debris
What is a short period comet
they have an origin from beyond neptune called the kuiper belt
-they have an orbital period of 10s-100s of years.
-they have low eccentricity
-prograde orbit
WHat is a long period comet
they have an origin within the Oort cloud (further than kuiper)
-they have an orbital period of thousands to millions of years
-they have high eccentricity
-prograde OR retrograde motion
-They rarely enter the planetary region
What is the heliosphere
An extended feature of the Sun’s influence, it is a bubble surrounding the solar system created by solar wind. Has a cigar shape due to Sun’s movement.
WHat is the Oort cloud
a theoretical spherical region around 10,000AU-20,000AU
-consists of long period comets and can be disturbed by other Stars (not our Sun)
How can you deduce the orbit of a comet using its trajectory around the Sun
If the comet travels at a velocity of elss than the escape velocity required to leave the solar system, it will have an elliptical orbit around the Sun
>Comets travelling through the escape velocity can be captured by the Sun or thrown out of orbit by its gravitational pull, giving a parabolic orbit