science grade 9 Flashcards
Why do we always see one side of the moon?
Because the revolution and rotation speed for the moon is the same
Gravitational force
the force of attraction between all mass in the universe ( the greater the mass the stronger force of gravity )
Who introduced the “heliocentric model”
Nicolas Copernicus
what causes seasons
the earths tilt
why do we get seasons because of the tilt
when tilted towards the sun we get more focused sun light causing summer, when were tilted away we get less sun light causing winter
solstice
occurs twice a year when earth is most tilted towards or away from the sun ( June 21 summers, December 21st winter )
equinox
occurs twice a year when the hour of day light and hour pf darkness are the same ( march 21 start of spring and september 21st start of fall )
Name all the moon phases
New Moon, waxing phase, full Moon, waning phases
Eclipse
Darkening of a celestial object due to the position of another celestial object
Solar eclipse
When the Moon forms a straight line between the Earth and the Sun blocking the sun.
Lunar eclipse
When the earth forms a stright line between the moon and the sun blcking all light but red causing the moon to be seen red.
Tides
The raising and falling of the oceans surface caused by the gravitational pull of the moon and sun
spring tides
During the new moon and full the sun and the moon are aligned causing extra high tides
neap tides
when the moon and sun are prependecular causing extra low tides
what is constellation
A group of stars observed from the earth (astronomers call them “regions of stars”)
