Topic 4: Space Flashcards
Universe
Consists of many galaxies seperated by empty space
Galaxy
A large cluster of stars (Milky Way/Andromeda)
Star
A large ball of matter that is undergoing nuclear fusion and emitting light. The sun is a star
Solar System
The sun + all the planets orbiting it
Planet
Large ball of matter that orbits a star
Exoplanet
A planet existing around another star, outside of our solar system
Satellite
Body that orbits a planet. Moons are natural sateilltes whereas communication satellites are artificial
Dwarf Planet
An object that orbits a star but it is not large enough to be a planet
Challenge of space travel: The distance
Travelling long distances in space is very difficult + requires a very fast speed, while maintaining energy and fuel
Solution for the distance in space
- Large distances can be travelled using ion drive, where a small unbalanced force allows a high velocity to be achieved over an extended period of time.
- Energy can be preserved + high velocites can be reached by ‘catapulting’ from a fast moving asteriod, moon or planet.
Challenge of space travel: The energy supply
Sufficent energy is required to power life support system for space travel
Solution for the energy supply in space
- Energy can be generated on a spacecraft using solar cells
Frictionless Environment in space
Maneuvering spacecraft in their frictionless environments is a very demanding operation. There are no outside particles or surfaces that can be used to control speed and direction. The spacecraft has to control this from within.
Risks in space travel (4)
- Exposure to radiation - can damage human cells
- Re-entry into the atmosphere can be extremely dangerous as they are exposed to varied and increased levels of radiation
- Fuel load on take off has a risk of ignition and explosion
- Pressure differential between the vacuum of space and the atmospheric pressure in the spacecraft poses a risk to the astronauts.
Asteroid
A group of rocks in space that orbits the sun
Lightyear
The distance that light travels in a year. This can be calculated using the equation: d=vt
Big bang theory
A theory that states that all current and past matter in the universe came into existence at the same time.
Big bang theory key points
- The universe is 13.8 billion years old
- The universe is still expanding at an increasing rate
- Expanded as a signularity from a hot, tiny and dense point
What is white light made up of?
Range of colours
How can white light be seperated?
With a glass prism to obtain a spectrum
Continous spectrum
What would be seen from a source of white light
Line emission spectrum
When elements are heated, they glow. If this light is passed through a prism, it produces this spectrum
Absorption spectrum
When pure light is passed through an element in its gas form, this spectrum is produced
All elements emit…
a unique light spectrum
How can we see what elements different stars and planets contain?
Using spectroscopy and visualising line spectra
Evidence for big bang theory
- Red shift (evidence that galaxies are moving away from us)
- Background microwave radiation
- Heat energy in deep space