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.