Our Home "The Milky way"
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Objectives:
1. Students will Listen and watch a brief description about the structure of the Milky Way galaxy.
2. Students will gain understanding about the ideas and beliefs behind the true form of the Milky Way.
3. Students will be introduced to previous ways of explanation and myths concerning the Milky Way creation.
4. Students will ask questions and think about what it takes to make a galaxy.
5. Students will be asked to complete a hanging model of our own home galaxy the Milky Way.
6. Students will be introduced to the idea humans only have a 2D view of our own galaxy.
7. Students will then be shown that by exiting the galaxy and looking in, humans will be able to obtain a 3D view and a final conclusion on what our galaxy truly looks like.
Benchmarks:
CCG: Matter: Understand structure and properties of matter.
SC.05.PS.01 Identify substances as they exist in different states of matter.
SC.05.PS.01.01 Distinguish among solids, liquids, and gas.
SC.05.PS.01.02 Identify unique properties of each state of matter.
CCG: Force: Understand fundamental forces, their forms, and their effects on motion.
SC.05.PS.03 Describe and compare the motion of objects.
SC.05.PS.03.01 Recognize and describe the motion of an object in terms of one or more forces acting on it.
SC.05.PS.04 Identify examples of magnetism and gravity exerting force on an object.
SC.05.PS.04.02 Recognize that things on or near Earth are pulled toward it by Earth's gravity.
CCG: Energy: Understand energy, its transformations, and interactions with matter.
SC.05.PS.05.01 Identify various forms of energy including heat, light, sound, and electricity.
SC.05.PS.06 Describe examples of energy transfer.
SC.05.PS.06.01 Identify the direction of heat transfer on a diagram showing objects at different temperatures.
SC.05.PS.06.02 Identify ways to produce heat including light, burning, electricity, friction, and as a by-product of mechanical and electrical machines.
SC.05.PS.06.03 Identify examples of energy transfer in the environment.
CCG: The Earth in Space: Understand the Earth's place in the solar system and the universe.
SC.05.ES.04 Describe the Earth's place in the solar system and the patterns of movement of objects within the solar system using pictorial models.
SC.05.ES.04.01 Describe Earth's position and movement in the solar system.
SC.05.ES.04.02 Recognize that the rotation of the Earth on its axis every 24 hours produces the night-and-day cycle.
CCG: The Universe: Describe natural objects, events, and processes outside the Earth, both past and present.
Materials Cost in $
Items that will have to be bought each year:
Mat Board $2.80 each X 6 16.80
Galaxy print outs 10 X 35 3.50
Foam balls $4.50 pack of 12 X 3 packs 13.50
Glitter $3.00 each X 3 9.00
Beads $.60 0.60
Milky Way candies 1 bag $3.00 3.00
Fishing line $2.30 2.30
Total $48.70
Items that will be used year after year (replace when out)
Crayons $2.00 X 2 4.00
Rubber Cement $1.40 1.40
Water colors $1.00 X 3 3.00
Glue sticks $.90 X 2 = 1.80
Color pencils $1.00 X 2 = 2.00
Overall total (start up cost) $60.90
Time:
Initial prep time: 2hr
Preparation time: 5 min
Instruction time: 20 min hrs
Clean-up time: 5 min
What Is A Galaxy? :What Is A Galaxy?;
1. Galaxies are clusters of stars, gas, dust, and everything else we have yet to discover in space. 2. Galaxies serve as the main factors in the study of our Universe. :1. Galaxies are clusters of stars, gas, dust, and everything else we have yet to discover in space. 2. Galaxies serve as the main factors in the study of our Universe. ;
Origin of Elliptical and Spiral Galaxies ~ :Origin of Elliptical and Spiral Galaxies ~;
The idea is that elliptical galaxy or spiral galaxy will form, depending upon when star formation occurs in the galaxy formation process. Because stars are small and they are far apart, they don't collide in the formation process. This allows the stars to maintain "roughly" their initial shape and to settle into a "roughly" spherical form. In this case, they become elliptical galaxies.
If the gas does not turn into stars quickly, then we have a system of collapsing gas clouds. The gas clouds are much larger and are more likely to collide during the formation stage. The collapsing material thus runs into opposing material as it tries to pass. The collisions do not allow the collapsing material to pass through each other and the material is forced to settle into a disk. After the disk forms, star formation begins in earnest and a spiral galaxy is produced.
So what type of galaxy is the Milky Way? ~
The Milky Way galaxy is classified as a spiral galaxy (pictured below)
1. Spiral galaxies are diskshaped assemblages with curving, dusty arms.
2. Spiral galaxies are named for the (usually twoarmed) spiral structures that extend from the bulge into the disk.
3. The spiral arms are sites of ongoing star formation and are brighter than the surrounding disk because of the young, hot OB stars that inhabit them. (OB stars:Hot, massive, short lived stars)
4. Roughly half of all spirals are observed to have an additional component in the form of a barlike structure, extending from the central bulge (can be seen in the above picture, at the ends of which the spiral arms begin..
5. Our own Milky Way has long been believed to be a barred spiral, although the bar itself is difficult to observe from our position within the Galactic disk.
Different structures of the Milky Way~
Galactic Center, Bulge and Nucleus: :Galactic Center, Bulge and Nucleus: ;
The bulge of the Milky Way is more spherical than the disk and is composed of stars which are more reddish than those in the disk.
The bulge its self is around 20,000 x 13,000 light years in size and holds up to 1,600 stars per cubic light year (ly x ly).
The Galactic Center is the rotational center of the Milky Way galaxy. It is located about 24,800 LY away from the Earth, in the direction of the constellation Sagittarius, where the Milky Way appears brightest.
Scientists hypothesize that a supermassive black hole lies in the Galactic Center of the Milky Way, as well as most (if not all) other galaxies.
Because of cool interstellar dust along the line of sight, the Galactic Center cannot be studied at visible, ultraviolet or soft X-ray wavelengths.
The available information about the Galactic Center comes from observations at gamma ray, hard X-ray, infrared, sub-millimetre and radio wavelengths.
Until we gain the necessary technology needed to fully view and understand what is truly in the center of the galaxy we will have to rely on these tools to give us glimpses and approximate ideas about what our galaxies center really holds.
Halo (Gould Belt):
The halo of our Galaxy is the large roughly spherical distribution of stars and other space matter of our Galaxy.
The stars (and globular clusters) are thought to have formed in the early stages of the formation of the Milky Way (and are referred to as Population II stars) and typically will therefore be stellar remnants, low mass stars, or other low mass objects (e.g., planets or brown dwarfs).
Halo stars are not the first generation of stars.
According to the measurements of the mass of the Milky Way, it is inferred that the bulk of the mass of the Milky Way is Dark Matter contained in the halo of the Galaxy.
It is not clear in what form the mass resides, however. Over the years, the halo material has been suggested to be in the form of normal stars, planet-sized objets, brown dwarfs, black holes, neutron stars, white dwarfs, and fundamental particles.
Spiral arms :Spiral arms ;
The regions of stars that extend from the center of spiral and barred spiral galaxies.
These long, thin regions resemble a spiral and thus give spiral galaxies their name.
Naturally, different classifications of spiral galaxies have distinct armstructures.
Sa and SBa galaxies, for instance, have tightly wrapped arms: Pictured below "Adramana" (This picture was taken with infared technology)
Credit:NASA/JPLCaltech/K. Gordon
Sc and SBc galaxies have very "loose" arms: Pictured below "Césky"
Credit: Hubble telescope
Sprial arms contain a great many young, blue stars (due to the high mass density and the high rate of star formation), which make the arms so remarkable.
Myths and Ideas about the Milky way
Common names:
· Birds' Path :The name "Birds' Path" is used in several Uralic and Turkic languages and in the Baltic languages.
· Milky Way: Many European languages have borrowed, directly or indirectly, the Greek name for the Milky Way, including English and Latin.
· Road to Santiago: The Milky Way was traditionally used as a guide by pilgrims traveling to the holy site at Compostela, hence the use of "The Road to Santiago" as a name for the Milky Way.[2] Curiously, La Voje Ladee "The Milky Way" was also used to refer to the pilgrimage road.[3]
· Silver River: The Chinese name "Silver River" (??) is used throughout East Asia, including Korea and Vietnam. In Japan, "Silver River" means galaxies in general.
· River of Heaven: The Japanese name for the Milky Way is the "River of Heaven"
· Straw Way: In a large area from Central Asia to Africa, the name for the Milky Way is related to the word for straw. It has been claimed that this was spread by Arabs who in turned borrowed the word from Armenian.[4]
· "There are many many more names from many more cultures but these are the ones most commonly known and used"
A Handful of Known Myths:
Greek: 3 myths
· The Greek name for the Milky way (Galaxias) is derived from the word for milk (gala). One legend explains how the Milky Way was created by Heracles when he was a baby.[2] His father, Zeus, was fond of his son, who was born of the mortal woman Alcmene. He decided to let the infant Heracles suckle on his divine wife Hera's milk when she was asleep, an act which would endow the baby with godlike qualities. When Hera woke up and realized that she was breastfeeding an unknown infant, she pushed him away and the spurting milk became the Milky Way.
· A story told by the Roman Hyginus in the Poeticon astronomicon (ultimately based on Greek myth) says that the milk came from the goddess Ops (Greek Rhea), the wife of Saturn (Greek Cronus). Saturn swallowed his children to ensure his position as head of the Pantheon and sky god, and so Ops conceived a plan to save her newborn son Jupiter (Greek Zeus): She wrapped a stone in infant's clothes and gave it to Saturn to swallow. Saturn asked her to nurse the child once more before he swallowed it, and the milk that spurted when she pressed her nipple against the rock eventually became the Milky Way.
· Older Greek mythology associates the Milky Way with a herd of dairy cows/cattle, where each cow is a star and whose milk gives the blue glow. As such, it is intimately associated with legends concerning the constellation of Gemini, with which it is in contact. The constellation was named for the twins, Castor and Polydeuces, who sometimes raided cattle. In addition, Gemini (in combination with Canis Major, Orion, Auriga, and the deserted area now called Camelopardalis) may form the origin of the myth of the Cattle of Geryon, one of The Twelve Labours of Heracles
· Armenian:
Ancient Armenian mythology called the Milky Way the "Straw Thief's Way". According to legend, the god Vahagn stole a straw from the Assyrian king Barsham and brought it to Armenia during a cold winter. When he fled across the heavens, he spilled some of the straw along the way.
· Egyptian
In Egyptian mythology, the Milky Way was considered a pool of cow's milk. It was deified as a fertility cowgoddess by the name of Bat.
· Cherokee
A Cherokee folktale tells of a dog who stole some cornmeal and was chased away. He ran away to the north, spilling the cornmeal along the way. The Milky Way is thus called Gili Ulisvsdanvyi "The Way the Dog Ran Away"
Where Are We in Our Galaxy?
The Sun (and therefore the Earth and Solar System) may be found close to the inner rim of the Galaxy's Orion Arm, in the Local Fluff or the Gould Belt
The distance between the local arm and the next arm out, the Perseus Arm, is about 6,500 lightyears.
The Sun, and thus the Solar System, is found in what scientists call the galactic habitable zone.
Lab:
1. Materials needed:
1 cut out of the Milky Way galaxy
Coloring materials. i.e.: glue and glitter, water colors, crayons, etc
Foam ball that has been cut in half
Marker or color pencil
2. Label the arms of the Milky Way along with the location of the sun on Orion’s arm (Use picture above for a exact location).
3. Color in the regions of the Milky Way that would hold old stars (red) and new stars (blue).
4. Color the foam ball using gold glitter, yellow or orange markers or watercolors.
5. Bring the pieces up to the front to be hung with fishing line, needle and bead.
6. Hold the finished Milky Way up eye level and view it from the side.
7. Flip the Milky Way to where the spirals are facing you and view it from this angle.
8. Think about what differences there are between the side view and the face view. What do these two different views tell us about how we see the galaxies from the Earth.
9. How will our views change when we are able to get outside the galaxy and look in on it?
10. A quick clean up and discussion on the ideas of our home view of the Milky Way.
11. Candy!