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Grade 9: Science > Unit E: Section 1.0 > Flashcards

Unit E: Section 1.0 Flashcards

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1
Q

What did the First Nations believe about the sky?

A

the night sky was a pattern on a blanket. The blanket, they believed, was held up by a spinning “world pole,” the bottom of which rested on the chest of a woman underground named Stone Ribs

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2
Q

When does the summer solstice occur in the northern hemisphere?

A

June 21

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3
Q

What does the summer solstice mark?

A

The longest period of daylight in the year and represents the start of summer.

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4
Q

When does the winter solstice occur in the northern hemisphere?

A

Winter 21

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5
Q

What does the winter solstice mark?

A

The shortest period of daylight in the year and represents the start of winter.

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6
Q

When does the spring equinox take place?

A

March 21

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7
Q

When did the fall equinox take place?

A

September 22

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8
Q

What happens on an equinox?

A

Day and night are equal

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9
Q

What did the ancient Mayans build to signify the equinox?

A

pyramids and other monuments to align with the seasonal position of certain stars.

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10
Q

Who created the Geocentric model?

A

Greek philosopher Aristotle

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11
Q

Explain the geocentric model

A

Earth was at the center. Surrounded by a series of

concentric spheres that represented the paths of the Sun, Moon, and five planets known at the time

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12
Q

How many planets were known at the time of the geocentric model?

A

5

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13
Q

Why did the stars not move in the geocentric model?

A

They were attached firmly to the outermost sphere

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14
Q

Who proposed the heliocentric model?

A

Polish astronomer Nicholas Copernicus

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15
Q

Explain the heliocentric model

A

The Sun was at the centre and Earth and the other planets revolved in orbits around it

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16
Q

What did scientists figure out about the orbits of planets?

A

They were ellipses and not circles.

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17
Q

What was stonehenge used to predict?

A

Solstices

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18
Q

What were sundials used for?

A

To measure the passage of time

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19
Q

What was a Merkhet used for?

A

To chart astronomical positions and predict the movement of stars

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20
Q

What was a quadrant used for?

A

To measure a star’s height above the horizon.

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21
Q

What was an astrolabe used for?

A

To make accurate charts of star positions

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22
Q

What was a cross staff used for?

A

To measure the angle between the Moon and any given star

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23
Q

What is the Astronomical Unit used for measuring?

A

Used for measuring “local” distances, those inside our solar system.

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24
Q

What is one astronomical unit used for measuring?

A

the average distance from the center of Earth to the center of the Sun, 149 599 000 km

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25
Q

What are distances beyond our solar system measured in?

A

Light years

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26
Q

What is the distance in a light year?

A

It equals the distance that light travels in one year.

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27
Q

What is a star?

A

A star is a hot, glowing ball of gas (mainly hydrogen) that gives off tremendous light energy.

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28
Q

What color are hot stars?

A

Red

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29
Q

What color are very hot stars?

A

Blue

30
Q

What diagram did Ejnar Hertzsprung and Henry Norris

Russell make?

A

They compared the surface temperature of stars with the stars’ brightness (luminosity)

31
Q

What are nebulae?

A

Huge accumulations of gas and dust

32
Q

What is the lifecycle of a star?

A
  • They start in areas called nebulae
  • The gravity between the gas and dust caused it to start collapsing into a smaller, rotating cloud of gas and dust.
  • Because it is spinning it causes more of the matter join which heats up the core and glows
  • Called a protostar
  • When the core reaches 10 000 000°C hydrogen turns to helium
33
Q

What is a protostar?

A

A glowing ball of matter

34
Q

What is the main sequence for sun-like stars?

A 
Nebula
Sun-like stars
Red Giant
White Dwarf
Black Dwarf
35
Q

What is the main sequence for massive stars?

A 
Nebula 
Massive Stars
Red Supergiant
Supernova
Black hole or neutron star
36
Q

What is the longest part of a life of a star?

A

Main sequence, converting hydrogen to helium in their cores.

37
Q

What happens if the hydrogen in a star is used up?

A

The stable state star shrinks in size, heating the helium core so that it first starts fusing to carbon, then to other elements. Then it will become a red supergiant

38
Q

What happens when the temperature of the core is to cool to continue the reaction?

A

The star continues to shrink becoming a white dwarf and then a black dwarf

39
Q

What is a black hole?

A

A highly dense remnant of a star in which gravity is so strong that not even light from the radiation going on inside the remnant can escape

40
Q

What are constellations?

A

The groupings of stars we see as patterns in the night sky. There are 88 constellations

41
Q

What are asterisms?

A

Unofficially recognized star groupings

42
Q

What is a galaxy?

A

A grouping of millions or billions of stars, gas, and dust held together by gravity.

43
Q

What are the types of galaxies?

A

Spiral
Elliptical
Irregular

44
Q

What does a spiral galaxy look like?

A

A spiral galaxy appears to have long curved arms radiating out from a bright central core

45
Q

What does an elliptical galaxy look like?

A

An elliptical galaxy has a shape similar to that of a football or egg and is made up mostly of old stars.

46
Q

What does an irregular galaxy look like?

A

Has no notable shape and tends to be smaller than the other two galaxy types.

47
Q

What type of stars provide light in a spiral galaxy?

A

Young stars provide most of the light in the arms. Older stars provide most of the light in the central region

48
Q

What type of stars provide light in an elliptical galaxy?

A

Made up mostly of old stars.

49
Q

What is the “protoplanet hypothesis”?

A

A model for explaining the birth of solar systems.

50
Q

What are the steps in the “protoplanet hypothesis”?

A
  1. A cloud of gas and dust in space begins swirling.
  2. Most of the material (more than 90%) accumulates in the center, forming the Sun.
  3. The remaining material accumulates in smaller clumps circling the center. These form the planets.
51
Q

What is the temperature of the surface of the sun?

A

5500°C

52
Q

What is solar wind?

A

The charged particles that flow out of the sun

53
Q

How is earth protected from solar wind?

A

By its magnetic field

54
Q

What are the 2 groups of the solar system?

A

The inner planets also called terrestrial, or Earth-like, planets; and the outer, or Jovian

55
Q

What are the characteristics of the inner planets/Terrestrial?

A

Tend to be smaller, rockier in composition, and closer to the Sun

56
Q

What are the characteristics of the outer/jovian planets?

A

The Jovian planets are large and gaseous and are located great distances from the Sun.

57
Q

What is the order of the planets from the sun?

A 
Mercury
Venus
Earth 
Mars
Jupiter
Saturn
Uranus
Neptune
58
Q

How is mercury similar to the moon?

A

No atmosphere and therefore no protection from the bombardment of meteoroids, asteroids, and comets.

59
Q

What does “period of rotation” mean?

A

How long is one day

60
Q

What does “period of orbital rotation” mean?

A

How long is one year

61
Q

Which planets are bigger than earth?

A

Jupiter
Saturn
Uranus
Neptune

62
Q

Where is the asteroid belt located?

A

Between Mars and Jupiter

63
Q

What are asteroids?

A

small, rocky bodies orbiting the Sun and lying mainly in a narrow belt between Mars and Jupiter

64
Q

What are comets?

A

Objects made up of dust and ice that travel through space

65
Q

When do comets tails glow?

A

When they get close to the sun

66
Q

What are meteoroids?

A

Small pieces of rocks flying through space with no particular path

67
Q

What is a meteor?

A

When one gets pulled into the atmosphere by Earth’s gravity, the heat of atmospheric friction causes it to give off light

68
Q

What are shooting stars?

A

Meteors

69
Q

What is a meteorite?

A

If a meteor lasts long enough to hit Earth’s surface

70
Q

What is azimuth?

A

The compass direction of which way to face

71
Q

What is altitude?

A

How high to look

72
Q

What is zenith?

A

The highest point directly overhead

Grade 9: Science (20 decks)

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