Questions for ‘Visiting Pluto’

Pluto and its largest moon show off two of their sides in this pair of New Horizons photos. Each of the dark spots on Pluto (orange, right) is roughly the size of the state of Missouri.


To accompany feature Visiting Pluto



Before reading:

1.    How many planets are there in our solar system, and what are their names?

2.    Pluto used to be a “planet.” From what you know, how does it compare to our solar system’s true planets?

During reading:

1.    Pluto is the doorway to the “third zone.” What is that?

2.    How many years ago was the solar system born?

3.    Based on the story, what two big events make Flagstaff, Ariz., pivotal to the Pluto story?

4.    What 1992 discovery suddenly sparked renewed interest in Pluto — and why?

5.    Describe what the Kuiper belt is and where it sits.

6.    Explain why astronomers felt a rush to get to Pluto before 2020?

7.    What was New Horizons’ first “sightseeing” diversion — and when did It occur?

8.    Name four types of instruments, and their function, carried by New Horizons for studying our solar system.

9.    What did William McKinnon mean when he expressed an interest in New Horizons investigating signs of “active geology” on Pluto?

10.   In what way will Pluto’s discoverer get to visit the distant world?

After reading:

1.    Do some research and find out which planets and dwarf planets have natural satellites — and then graph how many each has as a bar chart.

2.    Explain the difference between a planet and a dwarf planet (If you are uncertain, read the sidebar: What is a planet?). Now explain whether you think the International Astronomical Union made a good call on Pluto, using at least two arguments that are based upon the material that you read.


1.    It takes Pluto 248 Earth years to complete a trip around the sun. Now, figure out what percent of that Plutonian year a single Earth year (365 Earth days) represents.

2.    Clyde Tombaugh was due to pass by Pluto on July 14. How many days is that since he discovered the celestial world on February 18, 1930? (Hint: You’ll need to account for leap years.)