Astronomy Grade 8
Skylab
1973 U.S. space station
What is Earth's period of daytime?
24 hours
How long does it take the moon to cycle through its phases?
29.5 days
What is the diameter of the moon?
3,476 km diameter; 1/4 of Earth's (about the distance accross the United States
What is the length of time it takes for the Earth to orbit the sun once?
365 1/4
What is a satellite?
Any natural or manmade object that revolves around another object in space
Winter Solstice
December 21; First day of winter. shortest day of the year
What causes day and night on earth?
Earth's rotation on its axis
rotation
Earth's spinning on its axis
Who created the first calanders?
Egyptian astronomers
What phase must the moon be in for a lunar eclipse?
Full moon only
Who invented the telescope?
Galileo 1609
Why do you see a certain phase of the moon?
It depends on how much of the sunlit side of the moon faces Earth
Why is the moon's "day" and "year" the same length?
It take the moon 27.3 days to rotate once and 27.3 days to revolve around the Earth
Why do we only see one side of the moon?
It takes the same time to rotate as revolve
When did man land on the moon?
July 20, 1969 - Neil Armstrong
Summer Solstice
June 21; Fist day of summer;longest day of the year
Vernal Equinox
March 21; First day of spring; Equal number of daylight and dark hours
How does sunlight hit the Earth?
Most direct sun at the equator with less direct sun as you approach the poles
Which direction does the sun seem to move?
Rises in east and sets in the west
What was the name of the first person and satellite in space?
Russian Yuri Gagarin; Sputnik I
Autumnal Equinox
September 23; First day of Autumn; Equal number of daylight and dark hours
What calander do we use?
The Roman Calander; 11 months 30 or 31 days plus February with 28 or 29
What causes the seasons?
The tilt of the Earth and its orbit around the sun
When and how was the moon formed?
a large object hit Earth when it was forming and a blob or matter broke off and formed it
What is the moon?
a natural satellite orbitting the Earth
What does eclipse mean?
blocked out
What causes the phases of the moon?
caused by the changes in the relative positions of the moon, Earth and sun
What are maria?
dark, flat areas - used to be thought of as oceans
How do we study the moon?
from rocks gathered by astronauts
What causes the tides?
gravity; differences in how much the moon pulls on different parts of the Earth
What is a spring tide?
greatest difference between the high and low tides; New Moon and Full Moon Phase
Why is a day added to February every 4 years and what is it called?
it takes four years for each 1/4 of a day to add up to an extra day on February 29 called Leap Year
What are highlands?
mountains on the moon
What is latitude?
parallel lines that measure north and south
Shuttle program
reusable U.S. spacecraft; first launched in 1981
What is a geosynchronous orbit?
revolution aound the Earth at the same rate that the Earth rotates
What are craters?
round pits on the surface caused by impacts of meteoroids
What is the shape of Earth's orbit?
slightly flattened circle; oval
astronomy
study of the moon, stars and other objects in space
What is an umbra?
the darkest part of a shadow during an eclipse
axis
the imaginary line that passes through Earth's center and the North and South Poles
What is a neap tide?
the least difference the high and low tides; 1st Quarter and Last Quarter Moon Phase
What is a penumbra?
the lighter part of the shadow during an eclipse
What affects gravity?
the masses of the objects and the distance between the objects
What is a lunar eclipse?
the moon blocked out by Earth's shadow
What is revolution?
the movement of one object around another
What is an orbit?
the path that an object takes around another
What are tides?
the rise an fall of water every 12.5 hours; alternating high and low roughly every 6 hours
What is a solar eclipse?
the sun blocked out by the moon
Why are there satellites in space?
used for communications, navigation, collecting weather data, and research
Which direction does Earth rotate?
west to east
Where do you see a partial solar eclipse?
when you are in the penumbra
Where do you see a total solar eclipse?
when you are inside the umbra
