Flashcards in The Earth in the Universe Deck (87)
What is at the centre of the solar system
A star called the sun
How many planets in the solar system?
Make up a way of remembering the planets MVEMJSUN
eg My Vicious Earthworm Might Just Swallow Us Now
What is the planet nearest to the sun?
Name the planets in order, starting at the sun
Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune
What is a moon?
A ball of rock in an orbit around a planet
What is a comet?
A small lump of ice and rock in a very elongated orbit around the sun
What is an asteroid?
Irregular lumps of rock, mainly found in orbit around the sun in a belt between Mars and Jupiter
Where are the dwarf planets?
Beyond Neptune (though Pluto can go inside the orbit of Neptune)
How much of the mass of the solar system is in the sun?
Which is the heaviest planet?
Earth is larger than?
Venus, Mars, Mercury
What is the Milky Way?
What is a galaxy?
A group of stars
What is the speed of light?
3x10 ^ 5 km/s.
What is a light year?
The distance light travels in a year - about 9.5 million million km.
What evidence can we collect from distant stars?
Only the radiation they emit.
What is the difference between brightness and relative brightness?
Brightness is what the star is giving out, relative brightness is what we see from earth.
What happens to relative brightness as stars are further away?
How can relative brightness be used to calculate the distance of stars?
The difference of relative brightness can be used to calculate the difference between two similar stars
What are the problems of using relative brightness to calculate the distance to a star?
It is based on the assumption that the same type of star has a constant brightness. It is based on an estimate of the distance to one of the stars. Brightness can be affected by many things on earth, eg light pollution, dust.
Where are telescopes placed to avoid the distortion of earth's atmosphere?
How else can the distance of a star be measured?
How is parallax used?
The earth moves in orbit, so the star is observed 6 months apart, and it appears to move relative to stars that are further away. The amount of movement can be used to calculate the distance.
What are the problems of using parallax?
Only close stars appear to move as the earth orbit is small compared to interstellar distances.
How does the sun generate energy?
What nuclear fusion takes place in the sun?
4 hydrogen nuclei are fused to form helium
What elements are believed to have been present in the early universe?
Where do all the elements from hydrogen up to iron come from?
They have been produced by nuclear fusion in stars, then spread through the universe by stellar explosions.