Space physics

  • gravity force, weight = mass x gravitational field strength (g), on Earth g=10 N/kg, different on other planets and stars; gravity forces between Earth and Moon, and between Earth and sun (qualitative only)
  • our sun as a star, other stars in our galaxy, other galaxies
  • the seasons and the Earth’s tilt, day length at different times of year, in different hemispheres
  • the light year as a unit of astronomical distance