Space Physics

You will be able to

• Explain day and night, the seasons and the Moon's phases using the rotation of Earth, its tilted axis and the orbit of the Moon.
• Describe how the Sun's height in the sky and the length of the day change through the year at a given latitude.
• Calculate an average orbital speed using v = 2πr ÷ T.

You will be able to

• Describe how orbital period, orbital speed and surface temperature change with distance from the Sun.
• Explain why a comet speeds up as it approaches the Sun, in terms of the gravitational force and energy transfer between GPE and KE.
• Calculate the orbital speed of a planet from its orbital radius and period using v = 2πr ÷ T.

You will be able to

• Describe the life cycle of a star from an interstellar cloud of dust and gas to a white dwarf, neutron star or black hole.
• Explain why a main-sequence star is stable, in terms of the balance between gravity and the outward force from its hot core.
• Explain how a supernova recycles hydrogen and heavier elements into nebulae that form new stars and planets.

You will be able to

• Describe redshift as an increase in the observed wavelength of light from a receding galaxy.
• Determine the Hubble constant H₀ = v ÷ d from a graph of recession speed against distance.
• Estimate the age of the Universe as 1 ÷ H₀ and explain how redshift supports the Big Bang theory.