ASTRONOMY
The
solar system (1) Yr
8 The Solar System consists
of (i) a central
star,
the Sun (ii) the planets:
Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus,
Neptune and Pluto (iii) moons orbiting
planets [You will be expected
to be able to recall the order of the planets from the Sun
outwards] For the
higher tier you must also know about the nature of
asteroids
& comets The
solar system (2) Yr
8 A simple model of the
solar system to show the relative positions of (i) the Earth and the
Moon (ii) the Earth and the
Sun (iii) the Sun and other
planets in the solar system For the
higher tier you must also know where asteroids & comets
are to be found, and how their orbital motion about the Sun
differs from that of planets. The
Sun Yr
9 1. Stars
are sources of light, infrared and other forms of
electromagnetic
radiation. 2. The Sun is a
star. § Planets Yr
9 Planets
are non-luminous bodies orbiting stars, i.e. they don't emit
light, though they do emit infrared.
They are seen because they reflect light. The orbits of the planets
in the Solar System are slightly elliptical
(Mercury & Pluto have very elliptical orbits), and these
orbits all lie in the same plane (except for that of Pluto),
with the Sun more or less at the centre (an ellipse doesn't
have a centre). § Satellites Yr
9 Natural satellites
(moons)
are non-luminous bodies orbiting planets. Some planets are orbited
by several moons. § The
Earth Yr
9 Rotation of the Earth on
its axis is the cause of (i) day and
night (ii) the apparent nightly
movement of the stars. The time taken for the
Earth to orbit the Sun is a year (365.25 days). Tilt of the Earth's axis
relative to its plane of orbit is the reason for: (i) length of daylight,
and its gradual change from one season to
another. (ii) seasonal
changes § Artificial
satellites Yr
11 Uses of artificial
satellites limited to: (i) observing the
Earth (ii) monitoring the
weather Use of
artificial satellites in the exploration of the solar
system. Principle
and use of geosynchronous
satellites in communication systems. Theories
about the solar system Yr
11 Theories of how people in
different ages have believed the universe was organised, and
the reasons for those views limited to: (i) the geocentric
theory of the universe (ii) the heliocentric
theory of the universe [You won't be expected
recall specific ideas about these views] § Gravitational
forces Yr
11 The movement of planets,
moons, comets and satellites is determined by
gravitational
forces between
bodies. You should
know the factors that affect the size of the gravitational
force between bodies: i.e. the effect on the gravitational
force between two bodies of their masses, and their distance
apart. Evolution
of Stars Yr
11 § Stages in
the evolution of a star (i) a huge
volume of gas and dust is drawn together by
gravity. (ii) the
g.p.e. of this gas & dust is gradually converted into
random k.e. (i.e. into thermal energy) (iii) the
increase of thermal energy eventually triggers
thermonuclear
reactions & the star is born (iv) when
all the hydrogen in the core is used up the star expands
into a red giant (iv) the
red giant finally collapses and becomes a white
dwarf Evolution
of the Universe Yr
11 § The
outlines of the Big
Bang
theory as an explanation for the creation and expansion of
the Universe.
GCSE
syllabus: force & motion
GCSE syllabus: electromagnetism
Date Last
Modified: April
2003
Emanuel School, London SW11 !HS
All text and diagrams copyright of J.C.Naylor