1.34 Describe How the Orbit of a Comet Differs From that of a Planet

Halley's Comet - http://www.ottisoft.com/Activities/Halleys%20comet.htm

1.  Four differences between planets and comets are:
      a. Comets are usually made from ______
      b. Comets have highly elliptical ______ compared to planets
      c. Comets usually travel _____ than ______
      d. Comets usually have long ______, made when the heat from the sun melts the vaporises the comet

1.32 Explain the effects of gravitational force

1. The moon orbits the Earth because of the _______/_______ between them

2.The Earth attracts the moon, and the moon attracts the Earth with _______ but _______ force.

3. This is an example of Newton's _______ law.

4. Planets orbit the sun because of the _______of the _______ and the _______.

5. Artificial satellites orbit the Earth because of the _______between the_______ and the _______.

6. Comets orbit the sun because of the _______ of the _______ and the _______.

7. If the _______ were removed these objects would fly away at a _______ to the orbit path.

1.31 Understand gravitational field strength, g, and recall that it is different on other planets and the moon from that on the Earth.

Questions	Answers
What does small 'g' stand for in the equation W = mg?	gravitational field strength
What is approximate value of 'g' on Earth?	10
What is approximate value of 'g' on the Moon?	1.6
What are the units for 'g'?	N/kg
Why is this equation useful?	so we can find our weight from our mass
Why is 'g' different on different planets?	Because different planets have different mass
Which object in our solar system has the largest 'g'?	The sun
Explain why this object has the largest 'g'	it has the largest mass
Where on a planet is 'g' the greatest?	the core
What happens to the value of 'g' as you go further away from a planet?	decreases
How does this affect your weight?	decreases
Find your mass on the bathroom scales and then find your weight on different planets (click this link: http://www.exploratorium.edu/ronh/weight/), take a screen shot and upload the image to your blog	Click to enlarge image

http://www.freemars.org/jeff/planets/Luna/Luna.htm

There are  several theories as to how the moon was formed.
1. One theory is that after earth was hit by an asteroid, the moon was formed by the rocky fragments that were blown out from the earth.
2. The second theory is known as coaccretion. It proposes the current information about both the earth and the moon from clouds of material. The new moon is spun but the Earth's gravity field and starts to circle the Earth. Smaller solar bodies seem to be more irregularly shaped but larger ones are nearly spherical.
3. The third theory is known as Fission. This theory states that the moon was split off from the Earth rotating fast. The moon would have come from the basin of the Pacific Ocean.
http://wiki.answers.com/Q/How_was_the_moon_created

The moon is around four and a half billion years old

The moon spins once on its axis in precisely the same amount of time it takes to revolve around the Earth. Because of this, one side of the moon is never visible from Earth.
http://www.wisegeek.com/why-does-the-same-side-of-the-moon-always-face-the-earth.htm

The moon drifts by 3.8cm per year.

Because the moon is constantly moving further away from the earth, the lunar months will become longer. The maximum length of the day will be when the Earth rotates at the same speed that the moon orbits. The day and the lunar month will have the same length, (47 of our 24 hour days).
http://answers.yahoo.com/question/index?qid=20101205074136AAISsAm

The sun is 416 times larger than the moon.

The moon is at an average distance of 238,855 miles away from the Earth.

On 19th March 2011, the moon was the closest it has been to the Earth.

The moon has a lot of radiation with its deformed atmosphere because of all the changes going on at the time it was swept away. Although it might have once had an atmosphere when it was still young, the solar winds emitted by the sun were to strong for the moon's gravity. The moon also hardly has enough mass to have an atmosphere. The lack of a magnetosphere combined with the solar winds will take away all of the atmosphere.
http://in.answers.yahoo.com/question/index?qid=20080924220450AAeYJB7


The moon is a 1/4 the size of the Earth so the gravity of the moon is a lot less than the Earth's gravity. Weight is a measure of the gravitational pull between two objects. So on the moon, your mass would be the same, but you would weigh less.
http://www.moonconnection.com/moon_gravity.phtml

There have been 12 people on the moon. Harrison Schmidt was the last man on the moon.

The moon orbits the Earth because it is in motion. The moon's inertia, with the attraction of gravity will keep it in orbit. This is the same with the Earth and the sun.
http://wiki.answers.com/Q/Why_does_the_moon_orbit_the_earth_and_why_does_the_earth_orbit_the_sun

It takes 28 days to orbit.

The moon's position around the earth allows it to reflect sunlight into our night. We get different levels of the light because the moon's orbit around the Earth lasts about a month. A full moon will provide us with better light than a new moon. Because of the moon's gravitational pull on the earth, as the Earth rotates, the moon's pull will cause tides.
http://wiki.answers.com/Q/What_effects_does_the_moon_have_on_the_earth





There are 240 known moons in our solar system

Phases of the Moon