The universe contains many different structures. Some of these are listed below:
meteoroidsdwarf planetsstarsgalaxies \text{meteoroids} \quad \text{dwarf planets} \quad \text{stars} \quad \text{galaxies} meteoroidsdwarf planetsstarsgalaxiesWrite these structures in order of their typical size, from smallest to largest, in the boxes below:
xxxxxxxxxx→xxxxxxxxxx→xxxxxxxxxx→xxxxxxxxxx \boxed{\text{\phantom{xxxxxxxxxx}}} \rightarrow \boxed{\text{\phantom{xxxxxxxxxx}}} \rightarrow \boxed{\text{\phantom{xxxxxxxxxx}}} \rightarrow \boxed{\text{\phantom{xxxxxxxxxx}}} xxxxxxxxxx→xxxxxxxxxx→xxxxxxxxxx→xxxxxxxxxxState what the redshift of light from a distant galaxy indicates about its motion relative to Earth.
Explain how observations of redshift from distant galaxies provide evidence that the Universe is expanding.
Define the term light-year.
Scientists have discovered thousands of planets orbiting stars outside our Solar System (exoplanets). Suggest one reason, other than cost, why humans cannot currently send manned spacecraft to explore these planets.
An electromagnetic wave (radio signal) is sent from a space probe near Jupiter to a receiving station on Earth. The signal takes 2200 s to travel this distance. The speed of electromagnetic waves in space is 3.0 × 108 m/s.
Calculate the distance between the space probe and Earth.
59 exam-style questions on CIE IGCSE Physics 6.2.3a Galaxies and the scale of the Universe. Each one has a worked solution and a mark scheme showing where the marks go.