Orbits

...orbits & space exploration...

free simulations, worksheets, videos, images, animations and more.

Objectives:

• Be able to describe the orbits of planets, moons, and comets.

• Be able to recall and explain some of Isaac Newton's ideas about orbits.

• Be able to calculate the orbital speed of an object.

Task 1 - Starter

Hands up!

I know the answer!

Find someone who knows:

1) The names of the planets in order.

2) Three differences between the terrestrial planets and the gas giants.

3) The largest planet in the solar system.

4) The hottest planet in the solar system.

5) A fact about a planet in our solar system.

6) A fact about a moon in our solar system.

7) What comets, asteroids, satellites and galaxies are.

Your teacher will tell you which questions to discuss.

Task 2 - Newton's Mountain

Applet credit: this excellent Newton's Mountain applet was written by Michael Fowler, University of Virginia.

See more fantastic Fowler's Physics Applets here.

Click here to visit the Galileo and Einstein homepage.

This thought experiment is sometimes referred to as "Newton's Cannonball".

Isaac Newton imagined firing a cannonball from a tall mountain above the earth's atmosphere, in his famous thought experiment Newton's Mountain*.

Try firing the cannonball at different velocities and see what happens!

Applet credit: Michael Fowler, University of Virginia.

Click the image below to load the applet from his site.

*Your teacher may explain some of Isaac Newton's ideas to you.

These animations show the paths that would be followed by objects launched at different speeds.

Velocity=6km/s

Velocity=7.3km/s

Velocity=8km/s

Velocity=10km/s

Click on any of the animations to load in full screen.

By Lookang many thanks to author of original simulation = Todd Timberlake author of Easy Java Simulation = Francisco Esquembre - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=21961928

Task 3a - Orbits of planets, moons and comets

See more fantastic Flash, Java and HTML5 simulations FREE at http://phet.colorado.edu

Flash technology!

Note: PC only - this applet does not run on tablets or mobile devices.

This is another fun "orbits" applet, which runs on most platforms (Windows, Mac OS X and Linux).

Click to Run

Install Java to run this simulation (requires a proper computer - tablets and mobiles cannot run Java)

Use the orbital simulator to investigate the orbits of planets, moons and comets.

Applet credit: PhET. Load the simulation in full screen mode for best results.

Try the presets "Sun, planet", "Sun, planet, moon", and "sun, planet, comet".

You could also try setting up your own orbital systems!

Set the slider to "accurate" for higher precision calculations and better rendering of orbits. Switch off traces and observe the orbit carefully, and then switch them on to find out more about the orbital dynamics! Challenge: Try to set a moon in a retrograde orbit!

Click the image below to open the simulation in full screen mode*.

Click to Run

*It's MUCH better in full screen mode.

Task 3b - Orbits of satellites

There are lots of satellites and other objects in a low earth orbit.

Click here for a full screen version. Zoom in for more detail, using the mouse wheel.

Other satellites are in geostationary orbits, with an orbital period of 24 hours.

Click here for a full screen version. Zoom in for more detail, using the mouse wheel.

Watch this video, which shows astronauts on the International Space Station, orbiting in a Low Earth Orbit.

Astronauts on the International Space Station.

Discuss with the person next to you:

1) How does orbiting affect the mass and weight of the astronauts?

2) Why do the astronauts appear to be weightless?

3) How fast are the astronauts moving?*

*Think about the velocity of the astronauts relative to the Earth, and relative to the Sun. Think about the path they follow, viewed from each location.

Task 3c - Researching orbits

I am going to research orbits.

Use the orbital simulator*, laptops and text books to find out about the orbits of planets, moons, comets, asteroids, and satellites.

Record your findings in this table:

Click the image above to download the table as a word document.

Differentiated version coming soon.

Note: students can get to this page using the URL www.roguephysicist.com/orbits

Task 4 - Calculating orbital speeds

Your teacher will show you how to calculate the orbital speed of an object, using the moon as an example.

Try to calculate the orbital speeds of the following objects:

1) The I.S.S. orbiting the Earth.

The International Space Station is in a roughly circular orbit 400km above the Earth's surface (6800km from the centre of the earth), and completes an orbit every 90 minutes.

2) A geostationary satellite.

Circular orbit 36000km from the centre of the Earth. Completes an orbit every 24 hours.

3) Mercury orbiting the sun.

Approximately circular orbit, 58,000,000km from the sun, orbital period 88 days.

4) The Earth orbiting the sun.

Approximately circular orbit 150 million km from the sun. Completes an orbit every 365.25 days.

5) Jupiter orbiting the sun.

Approximately circular orbit, 778,000,000km from the sun, orbital period 12 years.

Extension: Does your answer to question four affect your answer to question one...?

Click the image above to download this homework task as a word document.

Homework

Find out about a historically significant space mission, a forthcoming space mission, or a recent space mission. Write a brief description of the mission, including:

1) a picture of the spacecraft and/or satellite.

2) The purpose of the mission.

3) The date of the mission*.

or projected date, if it has not yet launched!

4) Was it a manned or unmanned mission?

5) Where it travelled to.

6) The size and weight of the payload or satellite it carried.

.

Click the image above to download this homework task as a word document

NOTE: videos of APOLLO, SHUTTLE, BLUE SHEPHARD and SPACE X FALCON coming soon!