Jellyfish take on the Star Clusters!

Which detail supports the idea that our Sun is not a part of a star cluster?

• “It is so far away from other stars that it doesn’t really interact with them.” (paragraph 1)

• “They are so close that their gravity keeps them from drifting away from each other.”

  (paragraph 2)

• “If you can imagine the stars being connected to each other by invisible rods and moving through space as a single object, then you’ve got the idea.” (paragraph 2)

• “Globular and open clusters are different in many other ways, including how they form, what their stars are made of, and where they appear in the universe.” (paragraph 6)

What is the meaning of the word “astronomer” as it is used in the article?

• a designer and maker of telescopes

• an astronaut who travels to distant solar systems

• a writer who creates descriptive names for stars and planets

• a scientist who studies stars and other objects in space

Two main ideas in the article are that open clusters and globular clusters have little in common and that globular clusters are very old. Which sentence from the article provides support for both ideas?

• “Many globular clusters are as much as a few hundred light-years across.” (paragraph 3)

• “You can’t find a globular cluster with your own eyes; they are too distant and too dim.”(paragraph 4)

• “Compared with globular clusters, open clusters are young—just hundreds of millions of years old, not billions.” (paragraph 5)

• “Globular and open clusters are different in many other ways, including how they form, what their stars are made of, and where they appear in the universe.” (paragraph 6)

Read this sentence from paragraph 4.

Only the most powerful telescopes can get a good look at one of them. What idea from the article does this sentence support?

• Globular clusters are huge.

• Globular clusters are distant.

• Globular clusters are old.

• Globular clusters are spheres.

Which of these describes one way in which open clusters and globular clusters are the same?

• Both contain stars that are larger than our Sun.

• Both are impossible to see without a telescope.

• Both are formed through the same process.

• Both contain stars connected by invisible rods.

Based on information in the article, which statement is most likely true?

• Stars do occasionally escape from both kinds of star clusters.

• Stars exist for a longer period of time if they are in open clusters.

• People who are not scientists tend to think that all stars are field stars.

• People who are not scientists tend to think that all stars are field stars.

Which detail about globular clusters does the photograph on page 4 make clear?

• Globular clusters are extremely old.

• Globular clusters are made up of billions of stars.

• Globular clusters are spherical in shape.

• Globular clusters are impossible to see without a good telescope.

Which detail would be most important to include in a summary of the article?

• The gravity of Earth holds everything on the planet.

• Star clusters look like a single object in space.

• Globular stars are so tiny they just look like smudges.

• Scientists have learned more about our own Sun by studying clusters.

Which sentence from paragraph 2 supports the idea that star clusters are held together by gravity?

• “A star cluster is a group of stars in a small area.”

• “As a star cluster moves, its stars move as a group.“

• “Open clusters can be about 50 light-years across.“

• “The two types of clusters do not have a lot in common.”