Topic 1.0: Human Understanding Of Space And Earth Changes

Question 1

Solstices

Answer 1

Occurs in both the summer and the winter
It comes from the Latin words that mean “sun” and “stop”
Prediction of the approach of summer and winter was important to early people’s and many ancient civilizations built huge monuments to honour their beliefs about the change
They had a fairly accurate observations of the position and path of the sun throughout the year

Question 2

Summer solstice

Answer 2

In the northern hemisphere, the summer solstice occurs near June 21
It marks the longest period of daylight in the year and represents the start of summer

Question 3

Winter solstice

Answer 3

Occurs near December 21 in the Southern Hemisphere and marks the shortest day of the year and the start of winter

Question 4

Stone hedge

Answer 4

Is in southern England and is made of multiple stones that are standing in concentric circles. The massive stones mark the summer and winter solstices

Question 5

Equinox

Answer 5

Occurs twice… One in the spring (about March 21) and one in the fall ( about September 22)
The word comes from the Latin words that mean “equal” and “night”
During an Equinox the day and night are the same length

Question 6

Mayans of Central America

Answer 6

Built an enormous cylinder shaped tower at Chichen Itza a long time ago to celebrate the occupancy if the two equinoxes

Question 7

Ancient Egyptians

Answer 7

Built many pyramids and other monuments to align with the seasonal position of certain stars
The entrance passage of Khufu, the great pyramid at Giza, once lined up with Thuban ( a star from the constellation Draco) This helped them find the closest point to north.

Question 8

Aboriginals of southwestern Alberta

Answer 8

2000 years ago they used large rocks to build medicine circles in which key rocks aligned with the bright stars that rose in the dawn.

Question 9

Geocentric model

Answer 9

about 2000 years ago, Aristotle proposed a earth centred model to explain planetary motion
The model showed earth as the centre, surrounded by a series of concentric spheres that represented the paths of the sun, moon, and five planets known at the time
He asking believed that the stars were fixed on the outer centric sphere explaining that’s why they didn’t move

Question 10

Heliocentric model

Answer 10

In 1530, Nicholas Copernicus proposed a dramatically different model, one that explained planetary motion more simply than the geocentric model
He suggested that the sun was at the centre and the earth and other planets revolved in orbits around it.

Question 11

Galileo Gallilei

Answer 11

Used the new technology of the telescope that was discovered a little less than 100 years later
He confirmed solid evidence of Copernicus’s theory!
He also discovered mountains on the moon, spots on the sun, moons orbiting Jupiter and much more.

Question 12

Johannesburg Kepler

Answer 12

Is overs that the planets didn’t travel in circular orbits but in ellipses.
He discovered the missing part of Copernicus’s theory and made the solar system understanding more valid than ever before.

Question 13

Quadrant

Answer 13

Designed by the Egyptian astronomers to measure a stars hight above the horizon

Question 14

Astrolabe

Answer 14

Used by Arabian astronomers for centuries to make accurate charts of star positions

Question 15

Cross staff

Answer 15

Invented in the 14th century by Levi Ben gurson to measure the angle between the moon and any given star

Question 16

Telescope

Answer 16

Invented in the late 16th century
It revolutionized astronomy and allowed astronomers such as Galileo to see the night sky more than ever possible before
They could view the distance between planets and showed the existence of planet neighbours in the solar system
Today, almost 500 years after the early telescope, we started to use satellites that orbited earth and showed us even more about our universe. Such as learning that our star is only an average star and that there are billions of other galaxies out there!

Question 17

Astronomical units

Answer 17

Used for measuring “local” distances from the centre of earth to the centre of the sun
Astronomers use this when describing positions of the planets relative to the sun.

Question 18

Light years

Answer 18

It equals the distance that light travels in one year.
Used for vast distances beyond our solar system that are too large for our tiny measures in astronomical units
Light travels at a speed of 300 thousand KM per second
This means that we may be only receiving the light from stars that may no longer exist!

Question 19

Stars

Answer 19

Hot, glowing balls of gas (mainly hydrogen) that give off a tremendous light energy
The number of stars in the universe is in the billions of billions
Stars can vary greatly in their colours as well as mass, size and density
The colour of star depends on its surface temp… Hot stars look blue and cooler stars look red!

Question 20

Hertzsprung Russell diagram

Answer 20

Compared the surface temp of a stars with other stars brightness
He plotted the data in a diagram that discovered the distribution of star temp and brightness is not random
The diagram puts the stars into distinct groupings and shows part of our theory today of how stars change over periods of time.

Question 21

Nebulae

Answer 21

Huge accumulations of gas and dust
It is composed of about 75% hydrogen and 23% helium
The other 2% is oxygen, nitrogen, carbon and silicate dust

Question 22

Interstellar matter

Answer 22

Can come from exploding stars and it is gases and dust that exist in space between stars.

Question 23

Protostar

Answer 23

The first stage in a stars formation
The attraction of gravity acting between the atoms of gas and the grains of dust can cause a small area of the nebulae to start collapsing into a smaller, rotating cloud. It is drawn into a spinning ball and the mass at its core increases and the temp climbs. If the core gets hot enough it will glow. This is how a protostar forms

Question 24

Fusion

Answer 24

The process when the core of the protostar becomes very hot and the hydrogen changes to helium and releases great quantities of energy and radiation. A star is born.

Question 25

Sun-like stars

Answer 25

One of the two main types of stars that can form. Sun-like stars are smaller and start out as turning into a red giant and when they are in the last stages of life, they turn into white dwarfs and then eventually black dwarfs

Question 26

Massive stars

Answer 26

Are one out of the two main types of stars at the start
They are larger in mass and start forming into a red supergiant and then in the later stages they turn into a supernova, than if it is not all destroyed a neutron star or black hole

Question 27

Main sequence

Answer 27

The life stages of a star… They are converting hydrogen to helium in their cores and the outward pressure of radiation on the stellar material is counteracted by gravity, so the stars are at a stable state. They can stay like this for even billions of years!

Question 28

Creation of red Giants or red supergiants

Answer 28

Eventually the fuel in a star runs out cause the hydrogen in the core has been used up, the stable star shrinks in size, heating the helium core so it starts fusing to carbon and other elements. Gravity causes the star to contract and builds new layers due to nuclear reactions occurring and becomes larger. Resulting in a red giant if sun-like or red supergiant if massive.

Question 29

Final stages of a sun-like star

Answer 29

The final stage occurs when the fusion reaction stops
It ends when the core is no longer hot enough to keep the reaction going. The lowering in temp allows gravity to take hold and cause it to collapse slowly, gradually becoming a white dwarf star. Eventually it becomes so small that it turns into a cold, dark black dwarf that is very faded.

Question 30

Final stages of a massive star

Answer 30

When the fusion reactions stops the lack of heat input causes gravity to collapse quickly on the star itself… This results in a suddenly outgoing shock wave and causes the star to explode and form a supernova.
If the star is not fully destroyed during the process, what is left is known as a neutron star or a black hole.

Question 31

Neutron star

Answer 31

A rapidly spinning object only about 30km in diameter and is the result of a supernova explosion.

Question 32

Black hole

Answer 32

A highly sense remnant of a star in which gravity is so strong that not even light from radiation going inside can escape.
They are invisible to telescopes and astronomers only know about their existence because material near a black hole becomes very hot and bright.

Question 33

Constellations

Answer 33

Are groupings of stars we see in patterns of the night sky
Officially, their are 88 constellations recognized by the international astronomical Union
There are many unofficially recognized star groupings as well called asterisms. One of which is the Big Dipper in the northern hemisphere that is a part of the constellation Ursa Major.

Question 34

Who discovered constellations

Answer 34

Ancient Greeks saw the stars that make up Ursa Major as a bear whereas the early Blackfoot nation of North America also saw a bear. Ancient Europeans saw a variety of patterns including a chariot, wagon, and a plough

Question 35

Galaxies

Answer 35

A grouping of millions or billions of stars, gas and dust that is held together by gravity
Two main types of galaxies: elliptical and irregular
Astronomers have estimated there may be a billion billion galaxies in our universe!

Question 36

Spiral galaxy

Answer 36

Appears to have long curves arms radiating out from a central core
Young stars provide the most light in the arms. Older stars provide most light in the central region.
Our spiral galaxy is the Milky Way and is believed to contain 100 billion to 200 billion stars!

Question 37

Elliptical Galaxy

Answer 37

Has a shape similar to that of a football or egg and is made mostly of old stars.

Question 38

Irregular Galaxy

Answer 38

Has no notable shape and tends to be smaller than the other 2 galaxies.
A mix of old and young stars is found in this type of Galaxy

Question 39

Protoplanet hypothesis

Answer 39

Explains the birth of solar systems in 3 steps:
A cloud of gas and dust in space begins swirling
Most of the material accumulates in the centre to form the sun
The rest accumulated in smaller clumps circling the centre to form planets

Question 40

The sun

Answer 40

It is the centre of our solar neighbourhood and the telescope has allowed us to look directly at it.
The surface is always bubbling and boiling and the core is even hotter.
The sun gives off solar wind.

Question 41

Solar wind

Answer 41

The sun releases charged particles that flow out in every direction
This wind passes earth at average speed of 400km/s and earth is protected by it cause of its magnetic field.

Question 42

The planets

Answer 42

Make up our solar system and all have different features
It is divided into 2 distinct planetary groups: inner planets/ terrestrial and outer planets/ Jovian
Tech has enabled us to learn much more about our nearest neighbours in space.

Question 43

Inner/ terrestrial planets

Answer 43

Tens to be smaller and rockier in composition

They are closer to the sun than Jovian planets

Question 44

Outer/ Jovian planets

Answer 44

Are large and gaseous and are located great distances from the sun

Question 45

Planets (ten)

Answer 45

Closest to the sun- furthest:
Sun
Mercury
Venus
Earth
Mars
Jupiter
Saturn
Uranus
Neptune
Pluto

Question 46

Asteroids

Answer 46

Astroids are between the orbits of Mars and Jupiter, they lie in narrow belts and are rocky, small or metallic bodies travelling in space. They range in size from being several hundred kilometres wide to only a few metres wide. Scientists aren’t certain where the asteroids came from.

Question 47

Comets

Answer 47

Are described as “dirty snowballs” and are objects made up of dust and ice that travel though space
Their long tails and bright glow only appear when close to the sun… The sun heats up the material on the comet and gases are releases and are pushed away from the comet by solar wind.
They spend most of their time orbiting outer reaches of the solar system
Only when an event such as a close passing of another body, occurs might a comets path be pushed toward the inner solar system but miss the body by the regular ellipse it joins around the sun

Question 48

Meteoroids

Answer 48

Small pieces of rocks flying through space with no particular path
They range in size… They are practically invisible to most telescopes and we only see the ones that hurtle towards our atmosphere through earths gravity.

Question 49

Meteor

Answer 49

A meteoroid that is hurtled towards earth due to gravity and the heat of atmospheric friction causes it to give off light
These are considered “shooting stars”

Question 50

Meteorite

Answer 50

A meteor that has lasted long enough to hit earths surface. Some meteor showers are predictable, such as the Leonids

Question 51

Azimuth

Answer 51

The angle between the most northerly point of the horizon and the point directly below a celestial body; also the horizontal angle or direction of a compass bearing

Question 52

Altitude

Answer 52

The height of a celestial body above the horizon, ranging from 0 at sea level to 90• straight up

Question 53

Zenith

Answer 53

The highest point in the sky directly overhead

Question 54

Ecliptic

Answer 54

The path in the sky along which the sun appears to move

Question 55

Planetary motion

Answer 55

Planets can appear to stand still or can seem to speed up over time in their movements across the sky.
A person needs to wait only a few days or weeks to see a planet change its position. The word planet comes from the Ancient Greek word “wanderer”
There was many different interpretations of planetary motion ( orbits and ellipses) Theory’s were developed by different astronomers.