Howardites

The answer sheet for the worksheet Carbonaceous chondrites. Each answer comes with the reason, so it can be used to mark or to go over the questions with the class.

Back to the worksheet

Start here: Enthusiast · Teens and adultsAnswer sheet for teachers

Answers: Carbonaceous chondrites

  1. A: No, it shows complex chemistry happened naturallyThe compounds show natural complex chemistry in the early Solar System, not life in the asteroids.
  2. B: CVCV chondrites, named after Vigarano, have large chondrules and big CAIs.
  3. B: Australia, in 1969Murchison fell in Victoria, Australia, in 1969.
  4. A: Within weeks or monthsThese fragile chondrites react with Earth's air, and sulphates can grow on their surfaces within weeks or months.
  5. A: About 4 per centThey are rare: only about 4 per cent of observed falls, compared with about four in five for ordinary chondrites.
  6. True (Lift it with clean foil and seal it away dry)Clean tools and foil avoid contamination; water, plastics and handling can spoil its minerals and organic compounds.
  7. True (Fingerprints, plastics and dust)Organic compounds can be contaminated by fingerprints, plastics and dust, so clean tools and foil are used.
  8. Many are rare in life and have space isotope ratios (accept any answer with the same meaning)Many of the amino acids are rare or absent in Earth's living things, and their isotopes show they formed in space.
  9. A Mighei-like chondrite altered by water (accept any answer with the same meaning)CM means the Mighei-like group, and type 2 means it was altered by water but still shows chondrules.
  10. Complex organic matter (accept any answer with the same meaning)Much of their carbon, often a few per cent by weight, is complex organic matter.

Task

Answers will vary. The task comes from the lesson: Make a small chart of the carbonaceous chondrite groups with their letters, type meteorites and one key feature each. Use it to decode labels like CM2, CV3 and CI1.

Look for work that uses the key words correctly and gives a reason for each point.

Howardites · teacher copy: keep it separate from the pupil worksheets