Space Flashcards
Definitions from the N5 Space sub-unit
What is a star?
A large spherical ball of plasma, undergoing nuclear fusion at its core.
What is a planet?
A large ball of matter which orbits a star.
What is a dwarf planet?
An object that orbits a star but is not large enough or roughly spherical enough to be classed as a planet.
What is a moon?
A natural satellite of a planet or dwarf planet.
What is an asteroid?
An orbiting object which is even smaller than a dwarf planet. They are formed of rock and metals.
What is a solar system?
A solar system consists of a central star orbited by planets and other matter.
What is an exoplanet?
A planet existing around another star, outside of our solar system.
What is a galaxy?
A large cluster of stars, all orbiting a central gravitational point.
What is the universe?
The Universe is the sum of all matter, energy,
space, and time.
What is a Light-year?
Distance travelled at the speed of light in one year.
What is an Astronomical Unit?
The average distance from the Sun to Earth
What is the approximate age of the Universe?
~13.8 billion years
What is the ‘Big Bang’ Theory ?
About 13.8 billion years ago the whole Universe was a very small, extremely hot and dense region. From this tiny point, the whole Universe expanded outwards to what exists today.
What is a Continuous Spectrum?
Light, when seen through a prism or diffraction grating, shows all wavelengths of visible light.
What is a Line Spectrum?
Light, when seen through a prism or diffraction grating, shows only a specific set of wavelengths of visible light.
What is an Exoplanet?
A planet existing around another star, outside of our solar system.
What is Newton’s First Law?
An object will remain at rest, or travel in a straight line at a constant speed, unless an unblanced force acts upon it.
What is Newton’s Second Law?
An unbalanced Force acting on an object
will cause the object to Accelerate. The size
of that acceleration will depend on the size
of the Force and the Mass of the object.
What is Newton’s Third Law?
If object A applies a Force on object B, then
object B applies and equal but opposite Force on A.
What is a design feature to reduce air resistance?
A smooth streamlined shape
What is meant by Orbital Period?
The time taken for a satellite to complete one full orbit.
What is meant by Geostationary Orbit?
A satellite with an orbital period of 24 hours. This causes the satellite to appear stationary relative to a point on the Earth’s surface.
How does a Rocket Engine provide Force?
Force provided by the combustion of flammable fuel being directed out of a nozzle.
How does an Ion Engine provide Force?
Force provided by the acceleration of charged ions in an electrical field.
What is a “slingshot” manoeuvre?
As the spacecraft approaches the planet or large asteroid, the craft accelerates due the gravitational effect of the planet and increases its velocity. On passing the planet, it will be travelling faster than before.
How does a Radioisotope Thermoelectric Generator (RTG) generate electrical energy?
Heat energy is generated through radioactive decay. A thermocouple converts the heat energy into electrical energy.
How does a Solar Cell generate electrical energy?
Light energy is converted into electrical energy within a semiconductor.
How does a “Launch Abort” system work
Rocket motors quickly move the capsule away from the main rocket, allowing the astronauts to escape a dangerous or damaged rocket.
How does a “Heat Shield” work
Use of ceramics with high specific heat capacities to absorb the heat generated without changing temperature enough to be damaging to the rest of the craft. Use of ablative materials (materials which burn off) which dissipates the heat through convection as the material becomes a gas.
