8. space physics

• our star is called the sun
• the planets in the solar system go in the order Mercury Venus Earth Mars Jupiter Saturn Uranus
• the asteroid belt is in between Mars and Jupiter
• Jupiter has 16 moons
• Saturn has rings made out of rock and dust
• Pluto is a dwarf planet
• gravity between two planets depends on the mass of the planets and their seperation
• weight = mass x gravitational strength
• the seasons variate throughout the year from Earth being tilted on its axis
• daylight hours , temperature , suns height in sky at midday are all affected by the Earths axis
• Earth tilted towards the sun --> summer
• equinox --> 12 hours day and night
• lightyear is the distance travelled by light per year
• a nebula is a huge cloud of hydrogen gas and dust
• a protostar is when a nebula has collected into a sphere
• a main sequence star is a star that has started nuclear fusion
• a red giant is the size of the sun
• a red super giant is a high mass star
• a red giant turns into a white dwarf then a black dwarf
• a red supergiant explodes in a supernova explosion
• a supernova turns into a neutron star or a black hole
• the bigger a star is the hotter it's core , hydrogen turns to helium faster , heavier nucleii can be formed by fusion , less tume is spent as a main sequence star