Physics - Space

Order of the planets from the sun

Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto

Mnemonic for order of planets from the sun

My Very Enormous Mother Just Served Us Noodles

How was the sun formed

A cloud of dust and gas (nebula) pulled together by gravitational attraction

What is the solar system to scale

1mm = 10,000,000km in real life

What is our solar system made of

- made of one star
- eight planets
- dwarf planets including pluto
- natural satellites

What are natural satellites

the moons that orbit planets

What is our solar system a small part of

the milky way galaxy

What element was formed from the fusion of hydrogen nuclei

helium

How many stars are in the galaxy

millions

What creates a greater red shift

the further away a galaxy is, the faster it will be moving away from us

What process from the sun releases energy

nuclear fusion

What stars form black holes and when

extremely large stars from black holes at the end of their life

What is gravitational force

the force that pulls all objects with mass together

What is a satellite

anything that orbits the planet

How many stars are in our solar system

One, the sun

Why are planets attracted to stars

- they both have mass
- so are attracted by the force of gravity
- this provides the force needed for the planets to keep moving in a circle

What does nuclear fusion in stars produce

all of the naturally occurring elements except for hydrogen

What is produced in the supernova

elements heavier than iron

What must happen for a stable orbit

the radius must change if the speed changes

What must happen for a circular orbit

the force of gravity can lead to changing velocity but unchanged speed

What does the red-shift evidence

- that space itself is expanding
- supports the big bang theory

What does the big bang theory suggest

that the universe began from a very small region that was extremely hot and dense

Why was hydrogen the first to appear in the universe

because it is the simplest element made up of just one proton and one electron

What do fusion reactions lead to

- an equilibrium between the gravitational collapse of a star and the expansion of a star due to fusion energy
- the formation of new elements

What is the red-shift effect

- There is an observed increase in the wavelength of light from most distant galaxies.
- The further away the galaxies, the faster they are moving and the bigger the observed increase in wavelength

What is the doppler effect

- The doppler effect causes the wavelength of light from galaxies moving away from us to increase.
- This moves the position of absorption lines towards the red end of the spectrum, so it is called red-shift

What do observation of supernova past 1988 suggest

that distant galaxies are receding faster than ever

What does gravity provide

the force that allows planets and satellites (both natural and artificial) to maintain their circular orbits