Educational worksheet on solar system models and star formation.

Problem Overview:

The task involves filling in the blanks in two sections of a worksheet about the solar system and its formation. The first section compares the Geocentric and Heliocentric models of the solar system, while the second section explains the formation of the star and solar system.

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Solution:

#### Section 1: Views of our Solar System - Geocentric vs Heliocentric

1. Geocentric means _______ and was the view that the _______ was the centre of the solar system.
- Geocentric means Earth-centered.
- The view was that the Earth was the center of the solar system.
- Answer: Earth-centered, Earth

2. Heliocentric means _______ and is the view that the _______ is the centre of the solar system.
- Heliocentric means Sun-centered.
- The view is that the Sun is the center of the solar system.
- Answer: Sun-centered, Sun

3. At first, in the heliocentric view, it was thought that the planets' orbits were circular, but it was later discovered that the orbits are actually _______ which fits much better with what we actually see.
- It was later discovered that the orbits are elliptical (not perfectly circular).
- Answer: elliptical

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#### Section 2: Star & Solar System Formation

1. It all starts with a _______. This is a cloud of _______, hydrogen and helium gas, and _______.
- The formation begins with a nebula.
- A nebula is a cloud of dust, hydrogen, helium gas, and other elements.
- Answer: nebula, dust, other elements

2. The sun formed when a nebula _______, either due to _______ from a nearby star or from the _______ of an exploding star.
- The nebula collapsed under its own gravity.
- This collapse could be triggered by shock waves from a nearby star or the supernova explosion of a nearby star.
- Answer: collapsed, shock waves, supernova explosion

3. All atoms have a _______ force between them.
- All atoms have a gravitational force between them.
- Answer: gravitational

4. As the nebula collapses, the area with the most matter will have the _______ gravitational pull, and material starts being pulled towards this area.
- The area with the most matter will have the strongest gravitational pull.
- Answer: strongest

5. When the area gets big enough, the energy will cause it to start _______.
- When the area becomes massive enough, the energy causes it to start glowing.
- Answer: glowing

6. This area is now a _______. It is visibly shining due to _______ forces, but it is not yet a "star" as we know it.
- This area is now a protostar.
- It is shining due to gravitational contraction forces.
- Answer: protostar, gravitational contraction

7. High _______ begin to build in the core, and, as a result, high _______.
- High pressure builds in the core, leading to high temperature.
- Answer: pressure, temperature

8. When the temperature reaches _______ degrees Celsius, nuclear fusion begins.
- Nuclear fusion begins when the temperature reaches 15 million degrees Celsius.
- Answer: 15 million

9. After tens of thousands of years, the energy from the core reaches the outer layers and the star becomes a _______ star.
- After tens of thousands of years, the star becomes a main-sequence star.
- Answer: main-sequence

10. The _______ and other debris continue to revolve around the newly created star.
- The planets and other debris continue to revolve around the newly created star.
- Answer: planets

11. The larger clumps of debris have a _______ gravitational pull and will pull more matter towards them.
- Larger clumps of debris have a stronger gravitational pull.
- Answer: stronger

12. These clumps will become _______.
- These clumps will eventually become planets.
- Answer: planets

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Final Answer:

- Section 1:
1. Earth-centered, Earth
2. Sun-centered, Sun
3. elliptical

- Section 2:
1. nebula, dust, other elements
2. collapsed, shock waves, supernova explosion
3. gravitational
4. strongest
5. glowing
6. protostar, gravitational contraction
7. pressure, temperature
8. 15 million
9. main-sequence
10. planets
11. stronger
12. planets

Final Boxed Answer:
\boxed{
\text{See detailed answers above.}
}