the earth rotates once everyv24 hoursto give us nights and days
reasons for months
the moon revolves around the earth every 29 days giving us one month
reasons for years
the earth revolves around the sun every 365 daysgiving us 1 year
the reasons for seasons
how are tides caused?
by the tug and pull of the moons gravity
what is a solar eclipse
sun > moon > earth
what is a lunar eclipse
sun> earth > moon
what is retrograde motion?
example using earth and mars
when we approch mars in space it looks like it's slowing down
when we pass it, it seems like it is going backwards
the geocentric model
the earliest to imagine
the universe was a gigantic sphere with the earth at the center
it could not explain retrograde motion
what is the heliocentric model
by nicholas copernicus
made in the early 1500
the sun was at the center of the model
and all other planets rotated around the sun on the same solar plane
what is the order of the planets
My Very Excellent Mother Just Served Us Nine Pizzas
discription of mercury
iron richs core and rocky
description of venus
has green house effect cloud covered
description of earth
life and oxygen
description of mars
red dry river beds
description of jupiter
narrow dust rings LARGE
description of saturn
yellow wide rings, gas
description of urans
rings blue gas
descriptions of neptune
giant dark spot, rings,blue,gas
description of pluto
tiny, orbit not in the solar plane
the solar nebula theory
1) spaces between stars filled with gas and dust, mostly hydrogen
2) gravity pulls the dust and everything else to the middle
3) cloud spins faster and faster more hydrogen builds up in the center
4)large build up of gas in the centerwill become a star, the cloud flattens into a disk due to spinning
5) little pockets of gas accumulate and spin in the same direction as the cloud, planets will form as gases in the center compress. The temperature rises to 10 000 000 the star will light
6) solar winds from the new star blow away most of the hydrogen and helium from the inner reigons leaving chunks of heavy matter chunks grow in size becoming planets remaining planets become astroides and comets
life cycle of a star
1)are formed inside massive clouds of dust and gas called nebula
2)gravity pulls everything into a shrinking ball
the ball gets smaller and hotter
3) when the temperature hits 10 million degrees nuclear fusion begbegins
the H combine with the He
4) hot material pushes out while the gravity pulls it back in
when the forces become equal it is a main sequence star
what is a galaxy?
a huge collection of gas and dust with 100 billions of stars
what is the milky way?
400 billion of stars sprial galaxy
what are elliptical galaxies?
foot ball shaped
made of young stars and gas clouds
what are sprial gallaxies?
young stars two types of galaxies
spiral= round center
barred= spiral bar center
what are irregular galaxies?
have no shape
dust and rocks when objects are burning genorating light to make it visible they are called meteors
the meteors that are large enough to come in the earth
what state is our sun in now?
it is a main sequence star
what are comets?
mainly dust and ice while they orbit around the sun the material evaporates forming the tail
what are astroides?
minor planets, metal rich materials
what is a intermediate mass star?
called red giant
runs out of H in 10 billion years
outer surface expands 100 times
what are low mass stars
less gravatational pressure
doesn't consume H
ho material escapeseasily after 100 billion years
what are massive stars?
have more gravatational pressues consume hydrogen faster and quicker when fules run out it explodes into a super nova