VII. Getting toMars: Are we there yet?

(Finding out about Mars' orbit and NASA missions.)

click here for a printable version

In 1609 Johannes Kepler formulated the three Laws of Planetary Motion. Write an obituary for Kepler, including some of his other contributions
See Kepler: Renaissance Man
In Kepler: Renaissance Man scroll down to “The 'War with Mars'”

What was Kepler’s first law of planetary motion?

________________________________________________________________________
The orbits of all planets are ellipses; however, some are more elliptical than others. The amount of “ellipticalness” is called eccentricity.

Look at the information on Planetary Orbits.

Which of the three orbits shown in the diagram has the most elliptical orbit ? _________________

What is the eccentricity of Earth’s orbit? _________________

What is the eccentricity of Mars’ orbit? __________________

Which orbit is more like a circle? _______________________

How can you tell? _________________________________

Which planet has the most elliptical orbit? ________________

Which planet has the least elliptical orbit? ________________


For more information about ellipses and an activity about Kepler’s first law see: What is Orbit?

Find out even more about Kepler's Laws and use The Laws of Planetary Motion.

Since Earth’s orbit is relatively circular and Mars’ orbit is elliptical, there are certain times in their revolutions (their paths around the sun) when Mars is closer to Earth than at other times. When Earth and Mars are the closest to each other in their orbits it is called opposition, and this is a good time to travel to Mars. See Earth and Mars Orbit (you need Shockwave to operate this).

When will opposition occur in 2002? ______________

When will opposition occur in 2003? ______________

After 2003 when will opposition next occur? __________

How often do Mars and Earth line up? ______________
NASA plans its Mars missions based on when opposition occurs. See A Taste of Mars: Mars Sample Return Missions

In the table below list the name of the missions, when they will occur and what they will accomplish


   NAME OF MISSION       YEAR OF MISSION       PURPOSE OF MISSION   
     
     
     
     
     
     
     
     
     
     



NASA hopes that someday a human mission to Mars will occur. A trip from Earth to Mars can take 6 to 12 months of space travel.

If there were a human mission to Mars and we assume that return to Earth from Mars depends on opposition, what is the maximum time a human would be gone from Earth? _____________
Minimum time? ______________

If humans were to go to Mars they will have to stay there for quite a while! Clearly, for humans to go to Mars there are some big problems that have to be solved. Make a list of problems you can think of that need to be solved to sustain humans while they are on Mars.

  1. __________________________________________________________________

  2. __________________________________________________________________

  3. __________________________________________________________________

  4. __________________________________________________________________

  5. __________________________________________________________________

  6. __________________________________________________________________

  7. __________________________________________________________________

  8. __________________________________________________________________

  9. __________________________________________________________________

  10. __________________________________________________________________
Want to be a Martian Sun-Times reporter? Write a story using the facts you have learned in this lesson. Choose one of the styles of reporting that your teacher gave you. Email it to us!


Investigation I | Investigation II | Investigation III | Investigation IV | Investigation V | Investigation VI | Investigation VII | Investigation VIII
Martian Sun-times