Autumnal equinox
September 22-23
winter solstice
december 21-22
summer solstice
june 20-27
spring equinox
march 20-21
axis
an invisible line between the north pole and the south pole. It is tilted.
where does the sun rise and set
the sun rises in the east, moves across the sky, and sets in the west.
right angle
neep tide
strait line
spring tide
planets in order of the sun
1.) mercury
2.) Venus
3.) earth
4.) Mars
5.) jupiter
6.) saturn
7.) uranus
8.) Neptune
how many times do neep tides and spring tides occur each month
two times
solar system consists of
- stars
- planets
- moons
- asteriods
-meteors
- comets
(AU)
Astronomical unit
when was Pluto reclassified
2006
what are satellites
moons
loose balls of ice and rock with long, narrow orbits
comets
small rocky objects, often found between jupiter and mars
asteroids
luminous spheroid of plasma held together by self-gravity
star
geocentric model
earth is the center and all planets revolve around it.
Heliocentric model
the sun is the center and all the planets orbit around it
100-170 AD
Ptolemy further developed the geocentric model, his model was accepted for almost 1500 years
Geo means what in greek
earth
helio means what in greek
sun
310-230 BC
Aristarchus first developed the Heliocentric model. His model was not widely accepted for many years.
1543
Nicolaus Copernicus further developed the Heliocentric Model, even with his researched theory, many people needed more evidence.
late 1500s
Tycho Brahe and Johannes Kelper discovered that the planets orbited in a ellipse
meaning of ellipse
an oval shape
1610 Galileo Galilei
Galileo used a telescope to discover 4 moons around Jupiter. this proved that not everything revolved around the earth. this led to other discoveries that helped prove that the planets revolve around the sun.