1. Earth Orbit to Mars Orbit The inner circle is Earth’s orbit. The outer circle is Mars’s orbit. Squares represent a rocket travelling from Earth to Mars. Each marker represents positions 40 days apart. Answer the following questions: 1)How many days in an Earth year? 2) How long does it take to get from Earth to Mars? 3) Why do the markers get closer together as the spacecraft reaches Mars? 4) What is the shape of the orbit? 5) Where would Mars have to be located at launch time so that it meets the spacecraft? Comets on a “Yo Yo” elipse orbit “3 months in the sun - years in deep space”

2. Earth Orbit to Mars Orbit The inner circle is Earth’s orbit. The outer circle is Mars’s orbit. Squares represent a rocket travelling from Earth to Mars. Each marker represents positions 40 days apart. Answer the following questions: 1)How many days in an Earth year? 2) How long does it take to get from Earth to Mars? 3) Why do the markers get closer together as the spacecraft reaches Mars? 4) What is the shape of the orbit? 5) Where would Mars have to be located at launch time so that it meets the spacecraft? Comets on a “Yo Yo” elipse orbit “3 months in the sun - years in deep space” 0 40 80 120 160 200 240 280 320 320 Days (365 Days)

3. Earth Orbit to Mars Orbit The inner circle is Earth’s orbit. The outer circle is Mars’s orbit. Squares represent a rocket travelling from Earth to Mars. Each marker represents positions 40 days apart. Answer the following questions: 1)How many days in an Earth year? 2) How long does it take to get from Earth to Mars? 3) Why do the markers get closer together as the spacecraft reaches Mars? 4) What is the shape of the orbit? 5) Where would Mars have to be located at launch time so that it meets the spacecraft? Comets on a “Yo Yo” elipse orbit “3 months in the sun - years in deep space” 0 40 80 120 160 200 240 280 320

4. Earth Orbit to Mars Orbit The inner circle is Earth’s orbit. The outer circle is Mars’s orbit. Squares represent a rocket travelling from Earth to Mars. Each marker represents positions 40 days apart. Answer the following questions: 1)How many days in an Earth year? 2) How long does it take to get from Earth to Mars? 3) Why do the markers get closer together as the spacecraft reaches Mars? 4) What is the shape of the orbit? 5) Where would Mars have to be located at launch time so that it meets the spacecraft? Comets on a “Yo Yo” elipse orbit “3 months in the sun - years in deep space” The space craft is slowed by the sun’s gravity (Like a foot ball kicked into the sky)

5. On a small moon you can hit a ball into orbit.

6. Earth Orbit to Mars Orbit The inner circle is Earth’s orbit. The outer circle is Mars’s orbit. Squares represent a rocket travelling from Earth to Mars. Each marker represents positions 40 days apart. Answer the following questions: 1)How many days in an Earth year? 2) How long does it take to get from Earth to Mars? 3) Why do the markers get closer together as the spacecraft reaches Mars? 4) What is the shape of the orbit? 5) Where would Mars have to be located at launch time so that it meets the spacecraft? Comets on a “Yo Yo” elipse orbit “3 months in the sun - years in deep space”

7. Earth Orbit to Mars Orbit The inner circle is Earth’s orbit. The outer circle is Mars’s orbit. Squares represent a rocket travelling from Earth to Mars. Each marker represents positions 40 days apart. Answer the following questions: 1)How many days in an Earth year? 2) How long does it take to get from Earth to Mars? 3) Why do the markers get closer together as the spacecraft reaches Mars? 4) What is the shape of the orbit? 5) Where would Mars have to be located at launch time so that it meets the spacecraft? Comets on a “Yo Yo” elipse orbit “3 months in the sun - years in deep space”