The SAT Reading Comprehension: Basic Principles

Page 3

The last supernova in our galaxy visible from
Earth was observed only five years before the
telescope was first used for celestial observation in
1609.

1. Telescopes were first used for celestial observation.
2. Since astronomers began using telescopes, they have observed no supernovas in our galaxy.
3. The last supernova in our galaxy occurred in 1604.
4. Supernovas can be seen from Earth by the unaided eye.
5. The telescope was invented five years before the last visible supernova occurred.

If you selected choice B—careful—you misread the passage and didn't consider all the choices. The choice says that no supernovas were visible from Earth, but astronomers could have observed supernovas from satellite-based telescopes. If you hadn't considered that possibility, you still should have worked your way through the other choices, because choice D is unquestionably the answer without any need to read between the lines.

If you selected choice C—careful—you misread the passage and didn't consider all the choices; you may also have misread the choice. The choice refers to when supernovas occurred, whereas the passage refers to when they were observed. Moreover, it would be impossible for us to know enough about our galaxy to say when the last supernova occurred.

If you selected choice D, you used process of elimination correctly and found the answer. Congratulations, this was a deceptively difficult question. If the last supernova was observed five years before telescopes were used to explore the night sky, then clearly supernovas were visible to the unaided eye.

If you selected choice E—careful—you misread the passage and the choice. The passage did not say when the telescope was invented, just when it was first used for astronomical purposes. See also the discussion to choice C, a similar error. Notice also that the choice refers to the last supernova visible but the passage refers to supernovas in our galaxy, a very big difference.