Q: State the main constituents
of the Solar System.
Q: Name the planets in order of
increasing distance from the
Sun.
Q: Name three dwarf planets in
the Solar System.
Q: What is an asteroid?
Q: What is a comet?
Q: What is a centaur?
Q: What is a Trans-Neptunian
object?
Q: State the features that
qualify an object as a ‘planet’.
A: Mercury, Venus, Earth, Mars,
Jupiter, Saturn, Uranus,
Neptune.
A: 8 planets, moons, dwarf
planets, asteroids, comets,
centaurs, Trans-Neptunian
Objects.
A: A minor planet. Small soild
bodies, with the majority
orbiting in the Main or Asteroid
Belt between the orbits of Mars
and Jupiter, including Vesta (the
brightest) and Pallas.
A: Ceres, Pluto and Eris. (Also:
Haumea, Sedna, Makemake.)
A: Show similarities to both
comets and asteroids; generally
A: Nuclei of ice, dust and rock
orbit the Sun between the orbits
that develop a gaseous coma
of Jupiter and Neptune, and
and tails when close to the Sun.
include Chiron, Hidalgo and
Asbolus.
A: An object that is in orbit
around the Sun, is large
enough to be spherical, and
has ‘cleared its orbit’ of other
objects.
A: Objects orbiting the Sun
beyond Neptune.
Q: What is the ecliptic?
Q: What is the Spaced Out
project?
Q: What is an astronomical
unit?
Q: Describe the orbit of the
planets around the Sun.
Q: What is the Zodiac?
Q: What is meant by the term
retrograde motion?
Q: Define the terms: perihelion,
aphelion.
Q: Define the terms: greatest
eastern elongation (GEE),
greatest western elongation
(GWE).
A: The world’s largest scale
model of the Solar System (in
terms of distances), stretching
across the UK from Cornwall to
Shetland.
A: The projection of the Earth’s
orbit onto the celestial sphere; it
may also be defined as the
apparent yearly path of the Sun
against the stars. It is inclined
to the celestial equator by
23.5o.
A: The planets orbit the Sun in
slightly squashed circles or
ellipses. The plane of the
Earth’s orbit is called the
ecliptic and the planes of all the
planets are inclined by only a
few degrees to this.
A: 1 AU is defined as 150
million km (the mean distance
between the Earth and the
Sun).
A: Orbital or rotational
movement in the sense
opposite to that of the Earth’s
movement or rotation. A planet
is said to move in an apparent
retrograde direction when
shifting from east to west on the
celestial sphere.
A: A belt stretching right round
the sky, 8o to either side of the
ecliptic , in which the Sun,
Moon, and planets (apart from
Pluto) are always to be found.
A: Mercury and Venus are best
placed for observation when
they are furthest from the Sun
in the sky. The positions in their
orbits are known as GEE and
GWE and at these positions the
angle between the lines planetEarth and planet-Sun are 90o.
A: Perihelion = the position of a
body in the Solar System when
at its closest to the Sun.
Aphelion = the position of a
planet or other body when at its
greatest distance from the Sun.
Q: Define the term: conjunction.
Q: Define the term: opposition.
Q: Define the term: transit.
Q: Define the term: occultation.
Q: Describe the physical
characteristics of Mercury.
Q: Describe the physical
properties of Venus.
Q: What is the link between
Venus and global warming?
Q: Describe the physical
properties of Mars.
A: The position of a planet
when exactly opposite to the
Sun in the sky.
A: a) A planet is in conjunction
with a star or another planet
when it passes by it in the sky; b)
A planet is in superior conjunction
when it is on the far side of the
Sun with respect to the Earth,
and in inferior conjunction when
passing between the Sun and the
Earth.
A: The covering-up of one
celestial body by another.
Strictly speaking, a solar
eclipse is an occultation of the
Sun by the Moon.
A: a) The passage of a celestial
object across the observer’s
meridian; b) The projection of
Mercury or Venus against the
disc of the Sun.
A: Backwards-spinning, similar
size to the Earth. Clouds of
sulfuric acid, surface pressure
90X greater than the Earth,
surface temperature of 470 oC.
Dense atmosphere containing
carbon dioxide.
A: Heavily cratered and
contains highlands and lavafilled basins; many parts of its
surface appear almost identical
to the Moon.
A: Mars has iron-rich rocks,
seasonal ice caps and a 450 kmlong wtare-carved canyon called
Valles Marineris stretching eastwest across its surface. It also
contains the highest volcano in the
Solar System – Olympus Mons –
and violent dust storms rage across
its surface.
A: Venus has a dense
atmosphere containing CO2;
this prevents infrared radiation
leaving Venus, making the
surface and lower atmosphere
so hot – a ‘runaway
greenhouse effect’.
Q: Describe some of the
physical characteristics of
Jupiter.
Q: What are some of the
physical characteristics of
Saturn?
Q: What are the atmospheres
of Uranus and Neptune made
up of?
Q: State some differences in
the physical characteristics of
Uranus and Neptune.
Q: Name five general
Q: State some of the problems
techniques by unmanned
associated with manned
probes to investigate planets
exploration of the Solar System.
and other Solar System bodies.
Q: What are the names of the
two moons of Mars?
Q: What is the believed origins
of the moons of Mars?
A: Saturn is a similar gas giant
to Jupiter but it reveals less
structure in its atmosphere and
shows no evidence of long-term
features like Jupiter’s GRS.
Saturn’s most notable feature is
its majestic rings.
A: Jupiter rotates on its axis in only
10 hours, producing an equatorial
bulge and causing dynamic wind
systems that split the atmosphere
into a series of red-brown belts and
yellow-white zones. The Great Red
Spot (GRS) is an anticyclone
weather system, larger than the
planet Earth.
A: Uranus spins almost on its
side and its surface is almost
featureless; Neptune shows
many surface markings
(including the Great Dark Spot)
with dark banded features and
cirrus-like clouds of frozen
methane at high altitudes.
A: Both are gas giants of similar
size made up of hydrogen,
helium, methane and ammonia.
A: Space Adaptation Syndrome,
problems associated with living
in a zero-gravity environment
(brittle bones, muscle fatigue,
reduced red blood cell counts),
communication delays,
radiation risk, psychological
problems.
A: Flyby, orbit, landing, impact
collision, collecting and
returning.
A: Captured bodies from the
Asteroid Belt.
A: Phobos (Fear) and Deimos
(Terror).
Q: What are the names of the 4
Galilean moons of Jupiter?
Q: Which is the only moon in
the Solar System which has a
dense atmosphere?
Q: What is unusual about the
orbit of Triton around Neptune?
Q: What is the proposed origin
of Neptune’s moon Triton?
Q: What is the proposed origin
of Neptune’s moon Proteus?
Q: What is unusual about the
orbit of Neptune’s moon
Nereid?
Q: What is the Kuiper belt?
Q: What is the Oort cloud?
A: Saturn’s moon Titan, which
has an atmosphere that
extends 600 km from the
moon’s surface, consisting of
95% nitrogen and methane and
other hydrocarbons, which
creates a pressure of 1.5x that
of the Earth’s atmosphere.
A: Io, Ganymede, Calliso and
Europa.
A: Probably a captured body, but
because of its size and mass, Triton’s
capture might have been a result of a
collision with Neptune or another of its
moons. Some of Neptune’s small inner
moons may have been formed from leftover debris from such a collision. An
alternative is that Triton was once part of
a binary system, but only Triton was
captured, hence its unusual orbit.
A: Its orbit is highly-inclined and
revolves around Neptune in the
opposite sense to that in which
Neptune spins (the only large
moon in the Solar System to do
so).
A: It is the most highly eccentric
orbit of any moon or planet in
the Solar System; it takes 360
days to orbit Neptune. It is most
likely a captured Kuiper Belt
object.
A: As Proteus orbits in the plane of
Neptune’s equator and in the same
sense as the planet’s spin, it is
suggested that Proteus formed at the
same time as Neptune. (Although some
astronomers believe that Proteus and
Saturn’s equally-dark moon Phoebe
were formed in a different part of the
Solar System and were subsequently
captured by the two planets.)
A: The outermost region of the
Solar System (at a distance of
1.5 light years from the Sun).
Consists of billions of small lumps
of rock and ice. The objects of
the Oort cloud are too faint to be
seen using visible light.
A: Frozen objects (mainly
methane, ammonia and water)
that lie mostly beyond Neptune.
Thought to be the source of
comets.
Q: What is a ring system?
Q: What are possible origins of
ring systems?
Q: What is a comet?
Q: What are the two classes of
comet?
Q: Where do the two classes of
comet originate?
Q: Is the Halley Comet a shortperiod or a long-period comet?
What is its period?
Q: What is the difference
between the nucleus and the
coma of a comet?
Q: Explain the two types of tail
on a comet?
A: Debris left over after the
formation of the planet; large
impacts between moons; a
moon that was torn apart
through tidal gravitational
forces; from material ejected
from the surfaces of moons by
meteoric impacts.
A: Billions of individual particles
of ice, rock and dust that range
from a few micrometres to
several metres in size. The
exact composition varies from
planet to planet.
A: Short-period comets (periods
of less than 200 years) and
long-period comets (periods of
greater than 200 years).
A: Balls of rock and ice (often
called ‘dirty snowballs’ or ‘icy
dirtballs’) that form tails in the
course of their highly-elliptical
orbits around the Sun.
A: Short-period comet, with a
period of 76 years.
A: Short-period comets
originate from the Kuiper belt
(30-50 AU from the Sun), longperiod comets originate from
the Oort cloud (about 50,000
AU from the Sun).
A: Blue-coloured, straight ion tail consisting of
atoms and molecules of gas (mostly carbon
monoxide) that have been ionised by the solar
wind (when they de-excite, atoms emit light by
fluorescence). Lighter-coloured, shorter,
broader and slightly curved dust tail produced
by radiation pressure that pushes particles out
of the nucleus; this tail shines by reflecting
sunlight and its curvature is due to the individual
dust particles following their own independent
solar orbit.
A: Nucleus = the core of rock
and ice. Coma = extremely
rarefied sphere of gas and dust
surrounding the nucleus
(~100,000 km across) formed
as the temperature rises as a
comet approaches the Sun.
Q: Define the terms: meteoroid,
meteor, meteorite.
Q: What is a fireball?
Q: Name four annual meteor
showers.
Q: What is a radiant?
Q: What is a Near Earth Object
(NEO)?
Q: What is a Potentially
Hazardous Object (PHO)?
Q: What evidence is there for
collisions between astronomical
bodies?
Q: What scale is used to
categorise impact hazards and
potential risks?
A: A meteor with a magnitude of 3 or brighter.
A: Meteoroid = small rocky (with perhaps
some iron-nickel content) irregular lumps
of debris in the Solar System. Meteor =
when meteoroids enter the Earth’s
atmosphere, friction causes the
meteoroid and surrounding air to heat up
producing a short streak of incandescent
light. Meteorite = if part of a meteoroid
survives its passage through the
atmosphere, it lands on the Earth’s
surface and is called a meteorite.
A: The point in the sky from
which meteors of any particular
shower appear to radiate.
A: Perseids (August),
Quandrantids (January),
Leonids (November), Geminids
(December).
A: Any asteroid or comet with
A: An NEO whose orbit brings it an orbit that brings them close
within 0.05 AU of Earth; in
to the Earth (closer than 0.3
10/08 about 1000 were known. AU); in 10/08 about 5600 NEOs
were known.
A: The Torino scale.
A: Craters on the Moon, asteroids and
other planets; the unusual rotations of
Venus and Uranus; evidence for the
Giant Impact Hypothesis; direct
observation of the collision between
Jupiter and Shoemaker-Levy in 1994;
evidence of PHO impact craters on Earth
(Barringer, Chicxulub, Tunguska).
Q: What are the names of the
two models of the Solar
System?
Q: What was Copernicus’
contribution to the geocentric
vs. heliocentric argument?
Q: What was Tycho’s
contribution to the geocentric
vs. heliocentric argument?
Q: What is Kepler’s first law of
planetary motion?
Q: What is Kepler’s second law
of planetary motion?
Q: Mathematically, what is
Kepler’s third law of planetary
motion?
Q: What were Galileo’s three
major astronomical discoveries
relating to the Solar System?
Q: Who discovered Uranus and
how?
A: Proposed a heliocentric
model in order to explain the
occasional retrograde motion of
Mars, Jupiter and Saturn.
A: Geocentric and heliocentric.
A: Planets move in elliptical
orbit around the Sun, with the
Sun at one focus of each
ellipse.
A: Undertook meticulous
observations of the skies with
meticulous precision using his
purpose-built observatory on
the island of Hven, near
Copenhagen.
A: T2 = r3, where T is the orbital
period of a planet in years, and
r is its mean distance from the
Sun in AU.
A: An imaginary line from a
planet to the Sun sweeps out
equal areas in equal intervals of
time.
A: William Herschel in 1781. He had been
carrying out a ‘review of the heavens’ with a
home-made telescope from the garden of
his house in Bath, with particular emphasis
in faint naked-eye stars. He found one such
disc that he at first mistook for a comet, but
subsequent observations allowed him to
determine an orbit from which he deduced
the object to be a planet.
A: Phases and apparent size of
Venus; relief features of the
Moon; principal satellites of
Jupiter (Ganymede, Io, Callisto,
Europa).
Q: Who discovered Ceres and
how?
Q: Who discovered Neptune
and how?
Q: Who discovered Pluto and
how?
Q: What is gravitation?
Q: Mathematically, what is
Newton’s law of gravitation?
Q: What is meant by an inverse
square law?
Q: What are the three main
techniques for detecting or
inferring the presence of
exoplanets?
Q: What are the difficulties with
detecting individual planets?
A: Johann Galle and Heinrich d’Arrest
(assistants of Johann Encke) in 1846.
Discovered first night of telescopic
observation based on the predictions of
Urbain le Verrier, who predicted the
existence of Neptune to explain
perturbations in the motion of Uranus.
A: Giuseppe Piazzi in 1801. Several
astronomers had predicted that an
undiscovered planet lay in the obvious
gap between the orbits of Mars and
Jupiter. He observed the skies at the
Palermo Observatory and noted a faint
star had moved in position on several
successive nights.
A: The force of attraction that
exists between all particles of
matter in the Universe.
A: Clyde Tombaugh, and
American student, in 1930.
Located by photographic
techniques.
A: As the distance between two
objects doubles, the force
between them is one quarter of
its previous value.
A: F = Gm1m2/r2
A: Current methods do not
allow the discovery of small,
rocky exoplanets similar to
Earth because atmospheric
turbulence and the fact that
planets with a relatively small
mass have less significant
effect on their host star.
A: Astrometry, transit method,
radial-velocity method (using
Doppler shifts).
Q: What do scientists think are
the two essential chemical
ingredients for life?
Q: What are the two principal
theories for the origin of water
on Earth?
Q: What methods have
astronomers used to determine
the origin of water on Earth?
Q: What factors are included in
the Drake equation for
assessing the likelihood of life
existing elsewhere in our
galaxy?
Q: What is meant by the term
“habitable zone”?
Q: Name two other bodies in
our Solar System that are
candidates for micro-organisms
to exist.
Q: State some methods
astronomers use to search for
signs of life on other planets?
Q: What are the benefits and
advantages of discovering ET
life?
A: Outgassing of hydrogen and
oxygen from volcanoes that
combined to produce steam
that condensed into water;
deposited by comets
(containing ice) striking Earth
A: Carbon and liquid water.
A: Number of stars in our galaxy;
fraction of stars with planetary
systems; number of planets
capable of sustaining life; fraction of
life-forms that are intelligent;
fraction of these that can and wish
to communicate; fraction of a
planet’s lifetime for which such
civilisations can live
A: In 2004, ESA’s Rosetta space probe set
off on a 10-year journey to Comet
67P/Churyumov-Cerasimenko where, on
arrival, it will drop a small lander onto the
surface of the nucleus. One of the scientific
instruments, Ptolemy, will analyse the
comet’s water content and examine whether
it has the same relative abundances of
isotopes as water on Earth. The results will
help to determine the likelihood of
substantial amounts of our water being
‘delivered’ by comets
A: Mars, Jupiter’s moon
Europa.
A: A narrow range of distances
from the star in which the
temperature allows liquid water
to exist (sometimes called the
Goldilocks Zone because it is
“neither too hot nor too cold”)
A: Would it be wise to transfer organisms
from one environment into a totally
different one in which they might become
extinct or adapt too well and flourish? We
know nothing of the intent or capabilities
of possible alien life-forms – could
continued life on Earth be threatened?
Do we really want to discover that we are
not alone in the Universe?
A: Space probes, spectral analysis
of planetary atmospheres above
rocky exoplanets to search for
gases such as oxygen and
methane that are produced by living
organisms; analysis of radio waves
from space to try to detect signals
that have originated from ET
intelligent forms of life in our galaxy