NATs 1745: Midterm Exam Review - Chapters 1-2

‭EXAM REVIEW Chapters 1-2‬ ‭Chapter 1:‬ ‭ efine archaeoastronomy and list the cycles of the sky that have always been easily‬ D ‭observable and predictable.‬ ‭ rchaeoastronomy:‬‭The study of ancient sites and how‬‭people in the past have understood‬ A ‭the phenomenon in the sky and its cycles.‬ ‭Easily observable cycles of the sky include:‬ ‭●‬ ‭Mid-Summer‬ ‭●‬ ‭Spring and Fall Equinox‬ ‭●‬ ‭Mid-Winter‬ ‭ escribe the ancient sites discussed in this lesson, their relationship with the Sun,‬ D ‭and how their solar alignment appears to visitors of the site.‬ ‭ .‬ N 1 ‭ ewgrange‬ ‭-‬ ‭Large stone tomb comprised of a Roofbox that is aligned with the winter solstice‬ ‭sunrise‬ ‭-‬ ‭On this day a beam of sunlight hits the Roofbox and illuminates the floor‬ ‭-‬ ‭This civilization believed in some form of reincarnation- Rebirth‬ ‭ .‬ S 2 ‭ undagger of Chaco Canyon‬ ‭-‬ ‭Through the canyon are rock formations (One called Fajada Butte)‬ ‭-‬ ‭The summer solstice is the only day of the year when the ‘dagger of light’ perfectly‬ ‭cuts through the spiral carving‬ ‭-‬ ‭Theorized to be a sun shrine to worship the sun on these special days‬ ‭ .‬ S 3 ‭ tonehedge‬ ‭-‬ ‭Ring of stones‬ ‭-‬ ‭On the summer solstice, while inside the stone structure, the sun will rise the heel‬ ‭stone.‬ ‭-‬ ‭Stonehenge was likely used for ancient rituals tied to the sun rising/setting behind‬ ‭specific stones.‬ ‭ escribe the daily cycle of the Sun’s path in the sky and explain its cause. Given the‬ D ‭time of day and the Sun’s direction (N, SE, etc), identify the location of an observer on‬ ‭Earth relative to the Sun as well as the observer’s hemisphere.‬ ‭The Sun’s path in the sky:‬ ‭Due to Earth's 24-hour eastward spin, the Sun moves westward across the sky.‬ ‭●‬ ‭Rising east, setting west‬ ‭ -hemisphere:‬‭The Sun is mostly seen in the southern‬‭sky, reaching due south (exact‬ N ‭south) at noon.‬ ‭S-hemisphere:‬ ‭The Sun is mostly seen in the northern‬‭sky, reaching due north (exact‬ ‭north) at noon.‬ ‭Timezones:‬‭defined by the Sun's position in the sky relative to your location.‬ ‭ escribe the annual cycle of the Sun’s path in the sky and explain its cause, including‬ D ‭the meaning of the solstices and the equinoxes and the Earth’s orientation on those‬ ‭special days. Use this understanding to:‬ ‭●‬ m ‭ ake predictions about the Sun’s location in the sky at a given time of day and‬ ‭time of year‬ ‭●‬ d ‭ escribe how to design a site with an alignment to the solstices & equinoxes‬ ‭(ie, how would you identify the directions of the rising & setting sun on those‬ ‭days?)‬ ‭ quinox:‬‭Latin for Equal Night‬ E ‭Solstice:‬‭Solar Standstill (Sun reached its furthest‬‭point north and south)‬ ‭On the Northern Hemisphere:‬ ‭ all & Spring Equinox:‬ ‭sunrise is due E, sunset is‬‭due W; equal day & night‬ F ‭Winter Solstice:‬ ‭Sun rises and sets at its southernmost‬‭points; travels a short, low arc‬ ‭On the S-hemisphere:‬‭The sun's daily path arcs toward‬‭N rather than S‬ ‭ rediction:‬‭Identifying the Sun's rising/setting positions‬‭on the solstices simply requires‬ P ‭finding its N-most & S-most positions‬ ‭ esigned site:‬‭Make a notch in the ground that points‬‭to each sunrise position.‬‭Observe the‬ D ‭sun rising and setting for 365 days in one spot. After you would see the S-easternmost notch‬ ‭point to the winter solstice sunrise and the N-easternmost notch point to the summer solstice‬ ‭sunrise. Then the notch that is marked in the middle will mark the Fall/Spring Equinox.‬ ‭ xplain why Earth experiences seasonal changes, including why this experience‬ E ‭changes depending on the observer’s hemisphere. Use this understanding to make‬ ‭predictions about seasonal conditions on a planet with a different tilt than Earth’s‬ ‭‬ S ● ‭ easons change due to Earth's 23.5° tilt.‬ ‭●‬ ‭Winter occurs‬‭when the hemisphere is tilted away from‬‭the sun.‬‭Summer occurs‬ ‭when the hemisphere is tilted towards the sun.‬ ‭ efine the meaning of latitude and the special reference latitudes that have a‬ D ‭connection with the Sun. Describe how the Sun’s path in the sky varies with latitude‬ ‭and use this to explain the meaning of polar days and polar nights. Use this‬ ‭understanding to make predictions about where polar days, polar nights, and the‬ ‭tropics would be experienced on a planet with a different tilt than Earth’s.‬ ‭Latitude (L):‬‭a location's angle N or S of Earth's‬‭equator‬ ‭●‬ ‭The lower your latitude, the higher the Sun's daily paths and therefore the warmer the‬ ‭temperature‬ ‭●‬ P ‭ olar days‬‭and‬‭polar nights‬‭only occur within Arctic‬‭& Antarctic Circle; the higher the‬ ‭latitude, the more polar days/nights‬ ‭ efine the reference points and lines on the celestial sphere and describe the location‬ D ‭of an object in the sky using its altitude and azimuth. Use this understanding to‬ ‭explain why altitude and azimuth are relative coordinates.‬ ‭ elestial Sphere:‬‭our view of the sky projected onto‬‭an imaginary sphere to describe the‬ C ‭positions of celestial bodies.‬ ‭Reference points - specific to each observer‬ ‭ orizon:‬‭the circle around an observer that separates‬‭the visible and invisible hemispheres‬ H ‭of the sky.‬ ‭** Zenith:‬‭the point in the sky directly above the‬‭observer.‬‭**‬ ‭To describe the location of a celestial body in the sky is by using the:‬ ‭ .‬ a 1 ‭ ltitude:‬‭the object's angle upward from the horizon‬ ‭2.‬ ‭azimuth:‬‭the object's direction along the horizon‬ ‭-‬ ‭Since they are angles up and along the horizon they are relative coordinates‬ ‭Express angular sizes and distances in the sky using your hands and fingers.‬ ‭Angular units‬‭are used to measure objects in the sky‬ ‭_________________________________________________________________________‬ ‭Chapter 2:‬ ‭For the two ancient civilizations discussed in this lesson:‬ ‭●‬ ‭explain their general motivations for tracking the sky (ie, what their‬ ‭astronomical records used for)‬ ‭●‬ ‭describe their astronomical sites and/or record-keeping artifacts discussed in‬ ‭this lesson and what each was used for‬ ‭●‬ ‭identify the main feature of each of their written number systems that‬ ‭facilitated their ability to identify the celestial cycles‬ ‭ .‬ T 1 ‭ he Mayan Civilization‬ ‭●‬ ‭They tracked/predicted sky cycles to seek favour from the gods associated with‬ ‭celestial bodies. (Worship)‬ ‭●‬ ‭The Pyramid of Kukulclan‬ ‭-‬ ‭365 steps (Shows the awareness of the Sun’s annual cycle)‬ ‭-‬ ‭Annual patterns of light and shade track the time of year‬ ‭●‬ ‭El Caracol (Observatory):‬‭Tracked Venus cycles in‬‭sky‬ ‭●‬ D ‭ resden Codex (Bark Book):‬‭containing historical events‬‭and tables of celestial‬ ‭cycles‬ ‭ ayan Numbers:‬‭Were visually represented, making it‬‭easy to add and subtract large‬ M ‭numbers. Allowed Maya to identify patterns in the intervals between celestial events.‬ ‭ .‬ T 2 ‭ he Babylonian Civilization‬ ‭●‬ ‭Babylonians tracked celestial cycles because they believed the sky foretold the‬ ‭future.‬ ‭●‬ ‭Ruins on walls containing tablets:‬‭were used to track‬‭nightly sky logs and data‬ ‭ abylonian numbers:‬‭Their number system used the base‬‭of 60 which has a lot of factors.‬ B ‭This allowed them to record information easily. (We adopted units multiple of 60)‬ ‭ xplain the origin of the misconception that the Maya predicted the end of the world‬ E ‭on Dec 21, 2021.‬ ‭●‬ M ‭ ayan calendar notation ended on December 21, 2012, raising mistaken fears that‬ ‭this heralded the end of time‬ ‭●‬ ‭In truth, Mayan records describe this date as the last date of one calendar cycle, as‬ ‭opposed to the last date of all time‬ ‭Define lunation, state its length, and explain the cause of the Moon’s phase changes.‬ ‭Lunation:‬‭one complete cycle of moon phases (29.5‬‭days)‬ ‭●‬ ‭The moon phases are due to our changing view of the moon's sunlight side‬ ‭ ‬ ‭The more of the moon‬ ● ‭that is illuminated, the more of a‬ ‭nighttime moon it is.‬ ‭●‬ ‭Same the the other way‬ ‭Explain why solar and lunar eclipses were a common fear among ancient civilizations‬ ‭●‬ ‭In ancient times, eclipses were seen as bad s due to the diminishing appearance of‬ ‭the Sun/Moon & perceived unpredictability.‬ ‭ escribe the cause and appearance of solar and lunar eclipses, including the different‬ D ‭types of each eclipse (penumbral, partial, etc.) and the orientation of the Sun, Moon,‬ ‭and Earth during each type. Apply this knowledge to identify whether the appearance‬ ‭of each type of eclipse is location-depended or not, and explain why lunar eclipses‬ ‭are witnessed more often the solar eclipses‬ ‭ olar eclipse:‬‭occurs when the New Moon casts its‬‭shadow on Earth‬ S ‭- total:‬‭seen from parts of Earth in the Moon's primary‬‭shadow (umbra)‬ ‭- partial:‬‭seen from parts of Earth in the Moon's‬‭secondary shadow (penumbra)‬ ‭(location-depended)- depends if you are in the moon umbra or not‬ ‭ unar eclipse:‬‭occurs when a Full Moon passes through‬‭Earth's shadow‬ L ‭- penumbral:‬‭Moon passes through Earth's penumbra‬ ‭- partial:‬‭part of the Moon passes through Earth's‬‭umbra‬ ‭- total:‬‭entire Moon passes through Earth's umbra‬ ‭(Not location-depended) - We all see the same moon‬ ‭ efine an eclipse season, state its length and average frequency, and explain the‬ D ‭cause of its cycle.‬ ‭●‬ E ‭ clipses can only occur when the Moon is New/Full and the Earth-Moon-Sun are‬ ‭coplanar‬ ‭●‬ ‭Due to the tilt of the Moon's orbit, coplanarity only occurs 2-3 times per year and lasts‬ ‭31-38 days (eclipses seasons)‬ ‭ ow the Mayan eclipse tables were used, and why the Maya believed they‬ H ‭occasionally prevented an eclipse.‬ ‭‬ T ● ‭ he tables were used to record dates of eclipses to then predict future eclipses.‬ ‭●‬ ‭Whenever an eclipse was not seen on their predicted dates the Maya believed that‬ ‭the sun and the moon gods were satisfied by their sacrifices. (Eclipses are not seen‬ ‭every 6-5 lunations.)‬ ‭Why is it sometimes possible for 2 eclipses to occur in the same eclipse season‬ ‭●‬ ‭If an eclipse season starts on a new or full moon you will get either 2 lunar or solar‬ ‭eclipses.‬ ‭ xplain the importance of the planet Venus to the Maya, and why it is so easily‬ E ‭recognizable in the night sky.‬ ‭●‬ A ‭ war hero named Kukucan mysteriously disappeared into the mountains. The planet‬ ‭Venus rose at the same spot in the mountains where he disappeared. They believed‬ ‭Venus embodied Kukucan‬ ‭●‬ ‭Next to the Moon, Venus is the brightest object in the night sky‬ ‭Define heliacal rise and describe the cycle of Venus, including its length and how the‬ ‭planet’s time of visibility, as well as its appearance, changes throughout its cycle.‬ ‭Apply this knowledge to explain how the Mayan Venus records were used.‬ ‭ eliacal Rise:‬‭The first visible rising of a celestial‬‭object in the morning sky after conjunction‬ H ‭with the Sun.‬ ‭The cycle of Venus: Is a 584 day cycle‬ ‭ .‬ I‭nferior Conjunction:‬‭Venus's dark side faces Earth.‬‭(invisible)‬ 1 ‭2.‬ ‭Helical Rise:‬‭After a week venus reappears as a morning‬‭star. (The first appearance‬ ‭is brightest)‬ ‭3.‬ ‭Moving further away from Earth, gradually getting dimmer‬ ‭4.‬ ‭After about 8 months‬‭Superior Conjunction‬‭takes place.‬‭Venus is hidden by the‬ ‭sun.‬ ‭5.‬ ‭After 3 months of Superior Conjunction, Venus reappears as an evening star. (The‬ ‭first appearance is dimmest)‬ ‭6.‬ ‭Over the next 8 months, Venus will be seen after sunset, getting brighter gradually.‬ ‭(getting closer to Earth)‬ ‭7.‬ ‭Then when it reaches its brightest points it disappears and the cycle repeats.‬ ‭Mayan Venus records contained:‬ ‭●‬ ‭Kukuclan defined as Venus‬ ‭●‬ ‭The # of days and dates between Venus appearance and disappearance‬ ‭ or each of the visible planets, describe the key feature(s) of their appearance which‬ F ‭led to their chosen name.‬ ‭ .‬ 1 ‭2.‬ ‭3.‬ ‭4.‬ ‭5.‬ ‭ ercury:‬‭speedy scribe/messenger god; due to fast‬‭motion‬ M ‭Venus:‬‭goddess of love/beauty; due to its brightness‬ ‭Mars‬‭: god of war/bloodshed, due to its red color‬ ‭Jupiter:‬‭father of the gods; due to its brightness‬‭and majestic motion‬ ‭Saturn‬‭: god of old age; due to its faintness and slow‬‭motion‬ ‭ escribe the daily cycle of the stars, and how the stars’ paths change depending on‬ D ‭the direction the observer is looking as well as the observer’s latitude. Apply this‬ ‭knowledge to explain how, in the Northern hemisphere, we can use a star to‬ ‭determine our latitude on Earth.‬ ‭●‬ A ‭ s Earth spins daily, the stars appear to rotate around‬ ‭the North and South Celestial Poles‬ ‭●‬ ‭They always rise east and set west‬ ‭●‬ A ‭ n observer's latitude is given by the altitude of the visible celestial pole (the higher‬ ‭the latitude, the higher the Pole‬ ‭Explain why we see different stars and constellations at different times of the year.‬ ‭●‬ ‭Due to Earth's annual orbit, the visible stars/constellations change each night‬ ‭ xplain the significance of the star Sirius to the Ancient Egyptians, and how this star‬ E ‭was used as a calendar‬ ‭●‬ ‭The heliacal rise of Sirius (the brightest star in the sky) coincided with Nile's annual‬ ‭flood and was therefore used to mark the New Year‬ ‭ xplain the origin of the following calendrical elements:‬ E ‭- the 24-hour day‬ ‭●‬ ‭Egyptians tracked time at night using 12 constellations when used at roughly equal‬ ‭intervals, which led to a 24-hour day‬ ‭- the 60-minute hour and the 60-second minute‬ ‭●‬ ‭Babylonian Number system of a base of 60.‬ ‭- the leap day‬ ‭●‬ ‭Ptolemy IllI added another leap day every 4 years‬ ‭- the Julian calendar‬ ‭●‬ ‭The Julian calendar was created to address inconsistencies in tracking time,‬ ‭introducing a leap day every four years to better match the solar year.‬ ‭- the Gregorian calendar‬ ‭●‬ ‭The Gregorian calendar was then developed to refine leap-year’s 11.5 min error.‬ ‭ tate the location of the zodiac constellations and explain their significance to the‬ S ‭Babylonian astrologers:‬ ‭ odiac constellations are located along the ecliptic‬‭(the path of the Sun, and planets);‬ Z ‭used for making astrological predictions‬ ‭ xplain the astronomical meaning of your zodiac sign and why our zodiac signs have‬ E ‭changed since their original definitions by the Ancient Greeks.‬ ‭‬ Y ● ‭ our zodiac sign is the Sun's constellation in the month you were born‬ ‭●‬ ‭Sun's monthly constellations have shifted since the zodiac signs were assigned‬ ‭~3000 years ago (due to precession of the equinoxes)‬