Galaxies and the UniverseIB MYP Physics: Mind map

Exam questions on Galaxies and the Universe

1. A newspaper article reports that the Andromeda Galaxy is about 2.5 million light-years from Earth, and that our own galaxy, the Milky Way, contains over 100 billion stars.
   Explain what is meant by saying that the Andromeda Galaxy is 2.5 million light-years away, and what this means for the light we see from it.2 marks
2. Astronomers measure the light from several distant galaxies. In each case, the pattern of dark lines in the spectrum is found at longer wavelengths than the same pattern from a laboratory source. The more distant the galaxy, the greater the shift in wavelength.
   Explain how the fact that the shift is greater for more distant galaxies supports the idea that the Universe is expanding.2 marks
3. In 1965 two radio engineers in the USA detected a faint microwave signal arriving equally from every direction in the sky. It was later identified as radiation left over from the early Universe.
   Describe the Big Bang theory.3 marks