Space Exploration: Going Further

Distances, orbits and how anybody knows what a star is made of.

17 questions, free, marked as you go with a worked explanation on every one.

What this covers

The questions

  1. Light travels about 9.5 trillion km in a year. A star is 4 light years away. How many trillion kilometres is that?
  2. Astronomers say a star is made mostly of hydrogen and helium. How can they know that without going there?
  3. What keeps a satellite in orbit around Earth rather than flying off or falling down?
  4. Which technologies developed for space exploration are used on Earth? Select all that apply.
  5. A radio signal travels at 300000 km per second. Mars is about 78 million km away at its closest. How many seconds does a one-way signal take, to the nearest second?
  6. Why does that delay mean Mars rovers have to be partly autonomous?
  7. Which best explains why we see phases of the Moon?
  8. A telescope in orbit sees more detail than the same telescope on the ground. Why?
  9. Use the table. What pattern does the table show between a planet's distance from the Sun and its orbital period?
  10. Earth passes directly between the Sun and the Moon, casting its shadow on the Moon. This event is called a:
  11. The Moon passes directly between the Sun and Earth, blocking sunlight from a small area on Earth's surface. This event is called a:
  12. High and low tides along a coastline are caused mainly by:
  13. Alberta has longer days in summer than in winter. This seasonal change is caused mainly by:
  14. Earth spinning once on its axis takes about 24 hours. Earth travelling once all the way around the Sun takes about 365 days. These two separate motions are called, respectively:
  15. A satellite that orbits Earth once every 24 hours, matching Earth's own rotation, is called geostationary because it appears to stay over the same point on the ground. How many complete orbits does a geostationary satellite make in 7 days?
  16. Before telescopes, sailors and travellers used fixed patterns of stars to help figure out direction and location at night. These recognizable star patterns are called:
  17. The Sun's diameter is about 1.4 million km, and Earth's diameter is about 12800 km. About how many times wider is the Sun than Earth, rounded to the nearest ten?

Answer these free