The Hubble Telescope

1 The Hubble telescope was launched into space with great fanfare on April 25, 1990. Although there are many powerful telescopes at various locations on Earth, the Hubble telescope was expected to be able to provide considerably better information because it would be able to operate from the vacuum of space, without interference from the Earth's atmosphere. By launching the Hubble telescope into space, NASA was, in essence, placing an observatory above the Earth's atmosphere.

2 Unfortunately, the Hubble telescope was initially delayed in relaying its first pictures back from space due to a simple mathematical miscalculation. The Hubble telescope relies upon certain stars to orient its observations, and astronomers working on the pointing instructions for the telescope used charts created in 1950, with adjustments for the movements of the stars in the ensuing period. In making these adjustments, however, astronomers added the amount of the adjustment rather than subtracting it- a simple checkbook-balancing error. The adjustment was a change of only half a degree, but by adding half a degree rather than subtracting it, the telescope's aim was misdirected by millions of miles.

10. Why does the author mention many powerful telescopes at various locations on Earth in paragraph 1?

1. To emphasize the need for telescopes at various locations on Earth

2. To show that the Hubble telescope was different from existing telescopes

3. To indicate how the atmosphere improves the quality of information from space

4. To emphasize the similarities between the Hubble telescope and other telescopes

11. The author uses the phrase in essence in paragraph 2 in order to indicate information that follows the phrase

1. provides a simplified description of a previously stated situation

2. indicates the cause of a previously stated effect

3. provides further details about a previously stated main idea

4. indicates the classification to which previously stated examples belong

12. Why does the author begin paragraph 2 with Unfortunately ?

1. It indicates that NASA has been unhappy with all of Hubble's photographs.

2. It shows that NASA's plan to use stars to orient the Hubble telescope was misguided.

3. It emphasizes the need to have telescopes on Earth.

4. It indicates that high expectations were not initially met.

13. The author mentions a simple checkbook-balancing error in paragraph in order to suggest that

1. the astronomers must have difficulties with their checkbooks

2. the adjustment made by the astronomers should have been more than half a degree

3. a more balanced approach was needed when making adjustments

4. the mistake made by the astronomers was a simple, everyday error

14. Why does the author mention the detail millions of miles in paragraph 2?

1. It reinforces the idea that the mistake had a huge effect.

2. It emphasizes the wide range of the Hubble telescope.

3. It demonstrates that the Hubble telescope travels long distances.

4. It helps the reader to understand how powerful the Hubble telescope is.

PASSAGE FOUR (Questions 15-19)