Astronomy | Edexcel GCSE Physics, Higher tier (1PH0)

Astronomy

129 questions
10 subtopics
Paper 1
Paper 1

Astronomy is examined in Paper 1, Physics 1.

It covers weight and gravitational field strength on other bodies, the Solar System and the order of the planets, how ideas about the Solar System and ways of observing it have changed, orbits of moons, planets, comets and satellites, gravity, orbital speed and stable orbits, the Steady State and Big Bang theories, evidence for an expanding Universe, the Doppler effect and red-shift in galaxies, the life cycle of a star like the Sun and the life cycle of stars more massive than the Sun.

Sample questions from Astronomy

Answer each one closed book first, then open the answer.

Weight and gravitational field strength on other bodies

State the two properties of a planet that determine the gravitational field strength at its surface.

Show the answer
The mass of the planet and its radius, which sets how far the surface is from the planet's centre.
The Solar System and the order of the planets

Name one dwarf planet in our Solar System.

Show the answer
Pluto.
How ideas about the Solar System and ways of observing it have changed

How were the shapes of the planets' paths corrected after the first Sun-centred model was proposed?

Show the answer
Perfectly circular paths were replaced by slightly elliptical orbits, which matched the observed positions of the planets far better.
Orbits of moons, planets, comets and satellites

Describe the shape of the orbit of a comet around the Sun.

Show the answer
A comet follows a very elongated elliptical orbit that brings it close to the Sun and then carries it far beyond the planets.
Gravity, orbital speed and stable orbits

What name is given to the force that keeps a body moving in a circular path?

Show the answer
A centripetal force, which for an orbiting planet is provided by gravity.
The Steady State and Big Bang theories

Compare what the Big Bang theory and the Steady State theory say about the age of the Universe.

Show the answer
The Big Bang theory gives the Universe a definite age of roughly 13.8 billion years, while the Steady State theory gives it no age at all.
Evidence for an expanding Universe

Explain how red-shift in the light from galaxies provides evidence that the Universe is expanding.

Show the answer
Almost every galaxy is red-shifted, which shows they are all moving away from us, exactly as expected if the space between them is expanding.
The Doppler effect and red-shift in galaxies

When a wave source moves relative to an observer, does the frequency emitted by the source itself change?

Show the answer
No, the source emits the same frequency as before and only the frequency received by the observer is different.

The 10 subtopics

One subtopic is one session. Work down the list.

Subtopic	What it covers	Questions
Weight and gravitational field strength on other bodies	Why weight is smaller on the Moon while mass is unchanged, what sets a planet's field strength, and weight calculations on the Earth, the Moon, Mars and Jupiter.	8
The Solar System and the order of the planets	The Sun, planets, natural satellites, dwarf planets such as Pluto, asteroids and comets that make up the Solar System, and the eight planets in order of distance from the Sun, from Mercury to Neptune.	14
How ideas about the Solar System and ways of observing it have changed	The geocentric and heliocentric models, telescope evidence from Jupiter's moons and the phases of Venus, elliptical orbits, why models change, and observing by naked eye, telescope, photography and digital detectors, including radio, X-ray and orbiting telescopes.	15
Orbits of moons, planets, comets and satellites	The shapes of the orbits of planets, the Moon and comets, why a comet moves fastest near the Sun, and the orbits and uses of geostationary and low polar satellites.	8
Gravity, orbital speed and stable orbits	The direction of gravity on an orbiting planet, why circular motion is acceleration at constant speed, centripetal force, and how orbital speed must change with orbital radius.	12
The Steady State and Big Bang theories	What each theory says about the origin, density and age of the Universe, where they agree, why the Big Bang is accepted, and why red-shift alone cannot decide between them.	18
Evidence for an expanding Universe	Red-shift and the cosmic microwave background radiation as evidence for the Big Bang, why the CMB now arrives as microwaves from every direction, space itself expanding, a hotter denser past, and how finding the CMB ended the Steady State theory.	18
The Doppler effect and red-shift in galaxies	How observed wavelength and frequency change for a source moving away or towards an observer, the ambulance siren, what red-shift is, and how it grows with a galaxy's distance and speed.	14
The life cycle of a star like the Sun	The stages from nebula and protostar to main sequence star, red giant and white dwarf, hydrogen fusing to helium, why a red giant looks red, and how gravity and thermal expansion balance in a main sequence star until its hydrogen runs out.	14
The life cycle of stars more massive than the Sun	The stages from nebula to red supergiant, supernova, neutron star or black hole, why massive stars live shorter lives, and what supernova material goes on to form.	8

Astronomy is 129 of the 2,063 questions in the guide.Get the guide, £7

How the guide is worked

Answering a question from memory stores it far better than reading the answer again. The guide runs that as a fixed procedure on one subtopic at a time, about twenty minutes a session.

Step 1 · Closed book
Cover the answers. Work through one subtopic and write down what you can. Leave blanks where you have nothing.
Step 2 · Open book
Go back to the top. Read each printed answer and write it out in full, including the ones you had right.
Step 3 · Closed book again
Same questions, same order, from memory. The gap between pass one and pass three is the session result.

Read the full method, the return schedule and the research behind it.