Senior Science
Home > Senior Science > Options > Space Science > Space science: 1. No such thing as 'empty space'
9.9 Option – Space science: 1.
No such thing as ‘empty space’
| Syllabus reference (October 2002 version) | ||
|---|---|---|
| 1. While the atmosphere has
limits there is no such thing as ‘empty space’ |
Students learn to: |
Students: |
Extract from Senior Science Stage 6 Syllabus (Amended October 2002) © Board of Studies, NSW.
[Edit: 16 Sept 08]
Prior learning: Science Stages 4
– 5 Syllabus Outcome 4.7 (content 4.7.2) and Outcome 4.9 (content 4.9.1,2
and 4)
Background: The atmosphere is the
layer of air around the Earth. The atmosphere gets thinner the further you go
from the Earth.
gather,
process and present
information from secondary sources to model the relative distance of particles
in a solid, liquid, gas and in space
- Gather from several junior text books diagrams and information about models that show the comparison of particles moving in a solid, liquid and gas.
- Gather information about what scientists believe
to be the
distances between particles in space
, NASA Headquarters, Washington
DC, USA.
- Process information by comparing similar information about the relative distances between particles from different websites and texts. This will assist you to assess the reliability of the information.
- After this analysis, think about how you could use a simple model to show the relative distance of particles in space, compared with the more familiar models used to explain the relative distance of particles in a solid, liquid and gas.
- An effective way to present your model would be to use pictorial representations. This will allow you to show relationships clearly and succinctly.
discuss the concept of the atmosphere in relation to the distribution or concentration of particles of gas
- The atmosphere around the Earth is made up of several gases, mostly nitrogen and oxygen.
- Gas particles are free to move about in all directions, unlike liquids, that are confined to the container and the surface of the liquid.
- These gases are more concentrated close to the surface of the Earth as the gravity has an effect on them, acting towards the centre of the Earth. gravitational pull and will float off into space. This is particularly true of hydrogen as it is the lightest gas.
identify that the Earth’s atmosphere is maintained in space by the Earth’s gravitational pull
- The law of gravity states that any two objects attract each other with a force that is proportional to the product of their masses and inversely proportional to the square of the distance between them. Put simply this means bigger bodies have a bigger force and the further away bodies are the much less will be their force
- The Earth has a very big mass compared to individual gas molecules so the force of the gas particles on the Earth is negligible, but the Earth has a significant affect on the gas, therefore holding it around the Earth.
- The further away the gases are from the Earth’s surface the weaker is the gravity.
- The Earth’s atmosphere extends to about 3000 kilometres but it is very thin at this height.
- The concentration of the Earth’s atmosphere stays fairly constant for the first 100 kilometres.
- The Moon has much less mass so has less gravitational pull, therefore there is no atmosphere surrounding the Moon.
discuss why there is no such thing as empty space
- Space is more like a vacuum than anything on Earth but space is not a vacuum as there is matter in space.
- NASA scientists now believe that many atoms flying in space make up pieces of dust and gas that were already in space and have been pushed by explosions from super novae. They travel at close to the speed of light and are referred to as cosmic rays.
- There are tiny bits of rocks, often only the size of a pea, that are flying in space. If they enter the Earth’s atmosphere they glow and are commonly called meteors or shooting stars. Comets and asteroids are located in space.
For more information
Mostly
empty space Dr Pamela M Gay, Star Stryder
|