Space Flashcards
What is a galaxy?
A collection of billions of stars and their corresponding planets and moons.
What is a star?
A giant ball of Hydrogen gas which releases energy through nuclear fusion producing Helium and later other elements
What is a planet?
A rocky or gas body orbiting a star.
What is a moon?
A rocky or gas body orbiting a planet.
What is an asteroid?
A small rocky body orbiting a star.
What is a comet?
A small rocky and icy body orbiting a star.
What is the geocentric model?
The wrong idea that the Earth is at the centre of the solar system and the sun
and planets rotate around it. The Greeks developed this idea.
What is the heliocentric model?
The correct idea that the sun is at the centre of the solar system and the planets including Earth rotate around it. Copernicus and Galileo were instrumental in deciding this.
What is the Big Bang?
The singularity was a region so intensely hot that the normal particles of matter did not exist. Within a single moment this intensely hot singularity expanded rapidly. This is what we term the Big Bang. In the first few moments after the Big Bang the universe was so hot that we cannot imagine a level of temperature that great.
What is the lifecycle of a star?
- stellar nebula 2. yellow dwarfs 3. red giants 4. planetary nebula 5. white dwarf
Stars are formed when clouds of gas gather known as stellar nebulae.
These nebulae collapse under their own gravity to form stars which can burn for thousands or millions of years by converting Hydrogen into Helium. These are called yellow dwarves or average stars.
Eventually, the Hydrogen begins to run out and the start cool down. At this point they increase in size and form red giants.
The red giant burns out and some of the gases are lost to space. This is known as planetary nebulae.
Finally the remains of the star cool and collapse to form a very dense white dwarf.
Explain why there is seasons.
The seasons are caused by the tilt of the Earth, which is tilted at 23 degrees. This changes the angle that the sun hits the surface of the Earth and means that in the winter the sunlight is spread over a greater area. There is very little change in the suns angle near the equator so these areas do not experience seasons the way we do.
Learn the names of the moon phases.
Give 3 advantages of space travel.
- Some day we may need to colonise another planet in order to survive.
- We may be able to offer people space travel as a form of tourism.
- Some day we may discover and learn from new life.
Give 2 disadvantages of space travel.
- It is expensive - the money spent on space travel could be spent on fixing the problems on Earth.
- It is dangerous - many people have been killed both during and preparing for space travel.
During your studies you learned about a scientific model that helps us understand the origin of the universe. Name the model you studied and outline two pieces of evidence that support this model.
The Big Bang.
1. Stars look redder than they should. Which tells they are moving away from us.
2. Cosmic background radiation leftover
