Passage Summary: One scientist says these space rocks don't have germs because the shapes are too tiny, but he's wrong just because he disagrees with two other scientists who think space germs can shrink.

Conclusion: Professor Tagar's claim that the meteorite structures are not fossilized bacteria is incorrect.

Reasoning: Tagar rejects the theories of two other biologists who believe Martian bacteria could actually be as small as the structures found in the meteorite.

Analysis: This is a failure of logic regarding disagreement. The astronomer concludes Tagar is wrong simply because Tagar disagrees with someone else. Just because Tagar rejects a theory doesn't mean Tagar's own conclusion is false. Look for an answer that points out the astronomer is dismissing a position based on a disagreement rather than proving the position itself is factually incorrect.