CHAPTER 1 REVIEW QUESTIONS 1. What celestial event is ...
CHAPTER 1 REVIEW QUESTIONS 1. What celestial event is Newgrange aligned to? Describe what happens at Newgrange on this day. Newgrange is aligned to the winter solstice which occurs on December 21 st. On this day at sunrise, a beam of sunlight hits the roofbox & the light gradually illuminates the floor of the stone passage way.m As the sun gets higher and higher in the sky, the beam gets longer & longer it travels further down the passage & illuminates the main chamber 2. Describe what happens to the Sundagger on the solstices and equinoxes. At noon the solstices & equinoxes, the Sundagger exhibits 2 beams of sunlight which either bisect or frame the spirals. On the summer solstice the larger spiral is bisected by one dagger of sunlight. On the winter solstice the larger spiral is now framed by two daggers of sunlight. On the two equinox days (one in Fall & March) the noon sun is at its midpoint position between its highest & lowest position & that produces a small dagger which bisects the smaller spiral 3. What celestial event is Stonehenge aligned to? Describe what happens at Stonehenge on this day. On the longest day of the year (the summer solstice - June 22 nd) if you are standing inside the stone circle, you will see the sun rising behind the heel stone. 4. Why do archaeoastronomers suspect that Stonehenge’s Heel Stone had a missing partner stone? When Stonehenge was built, the summer solstice Sun rose beside the Heel Stone (due to the precession of the equinoxes) This suggests: there used to be 2 Heel Stones to frame the sunrise 5. What causes the Sun to rise & set every day? Earth’s rotation around the sun – due to Earth’s 24 – hour eastward – spin around its polar axis, Earth’s rotation around the sun – due to Earth’s 24 – hour eastward spin around its polar axis, the Sun moves westward across the sky; it rises in the east, reaches its highest point at noon, then sets in the west 6. What is the local time for an observer who is directly facing the opposite side of the sky from Sun? What is the local time when the Sun is at its highest point in the sky? What is the local time when the Sun is seen on the Eastern horizon? What is the local time when the Sun is seen on the Western horizon? local midnight, local noon, local sunrise, local sunset 7. What is the azimuth of the noon Sun in the northern hemisphere? How about the southern hemisphere?
The azimuth of the noon Sun in the Northern Hemisphere is North & the azimuth in the Southern Hemisphere is South 8. What does the word “solstice” mean? How does it describe what happens to the Sun’s rising and setting positions on the solstices? It means solar standstill – on the summer solstice the Sun’s path North stops before reversing directions and on the winter solstice the Sun’s path South stops before reversing directions 9. What is the azimuth of sunrise & sunset on the Northern winter solstice? How about the Northern summer solstice? How about the equinoxes? Winter solstice – sun rises furthest south east & sets on the furthest south west Summer solstice – sun rises furthest north east & sets on the furthest south west On the equinoxes – rises due east & sets due west 10. Describe how the Thirteen Towers of Chankilo, Peru were used to track the time of year. Given that this site is in the southern hemisphere, what is the approximate azimuth (NE, SE, NW, SW) of the winter solstice marker> How about the summer solstice marker? The towers consist of 13 stones on a hillside and they are spaced so that the rising (or setting) sun can be seen shifting between the stones from month to month. On the mid winter solstice – sun rises behind left most tower, during the next 6 months it rises behind all other towers in return – NE for the winter solstice marker & for summer solstice marker – SE 11. Which day is the longest day of the year and why? Which day is the shortest day of the year and why? What are the lengths of daytime and night time on the equinoxes? Longest day of the year – June 21/22 – summer solstice - traversing a long high arch – highest noon sun Shortest day of the year – Dec 21/22 – winter solstice – rises on the furthest south east & sets at the furthest south west – traversing a small low arch in the sky – shortest noon sun On the equinoxes the length of the day is 12 hours and 12 hours of night 12. What causes the seasons? Describe the orientation of the Earth relative to the Sun during Northern summer. What season does the Southern hemisphere experience at this time, and why? Seasonal changes are caused by Earth’s 23.5 degree orbital tilt around the Sun. In the Northern Summer, the Northern Hemisphere is tilted towards the Sun which means sunlight hits more directly, causing high arcs and more light per area. The Southern Hemisphere experiences Winter at this time because it is tilted away from
the Sun meaning sunlight hits indirectly – causing low arcs & giving it less light per are 0 in direct light feels weaker & is more spread out. 13. Within what latitudes can an observer see the Sun directly overhead? How did these latitudes get their names? Only within the tropics can the Sun be seen directly overhead – at 1
The azimuth of the noon Sun in the Northern Hemisphere is North & the azimuth in the Southern Hemisphere is South 8. What does the word “solstice” mean? How does it describe what happens to the Sun’s rising and setting positions on the solstices? It means solar standstill – on the summer solstice the Sun’s path North stops before reversing directions and on the winter solstice the Sun’s path South stops before reversing directions 9. What is the azimuth of sunrise & sunset on the Northern winter solstice? How about the Northern summer solstice? How about the equinoxes? Winter solstice – sun rises furthest south east & sets on the furthest south west Summer solstice – sun rises furthest north east & sets on the furthest south west On the equinoxes – rises due east & sets due west 10. Describe how the Thirteen Towers of Chankilo, Peru were used to track the time of year. Given that this site is in the southern hemisphere, what is the approximate azimuth (NE, SE, NW, SW) of the winter solstice marker> How about the summer solstice marker? The towers consist of 13 stones on a hillside and they are spaced so that the rising (or setting) sun can be seen shifting between the stones from month to month. On the mid winter solstice – sun rises behind left most tower, during the next 6 months it rises behind all other towers in return – NE for the winter solstice marker & for summer solstice marker – SE 11. Which day is the longest day of the year and why? Which day is the shortest day of the year and why? What are the lengths of daytime and night time on the equinoxes? Longest day of the year – June 21/22 – summer solstice - traversing a long high arch – highest noon sun Shortest day of the year – Dec 21/22 – winter solstice – rises on the furthest south east & sets at the furthest south west – traversing a small low arch in the sky – shortest noon sun On the equinoxes the length of the day is 12 hours and 12 hours of night 12. What causes the seasons? Describe the orientation of the Earth relative to the Sun during Northern summer. What season does the Southern hemisphere experience at this time, and why? Seasonal changes are caused by Earth’s 23.5 degree orbital tilt around the Sun. In the Northern Summer, the Northern Hemisphere is tilted towards the Sun which means sunlight hits more directly, causing high arcs and more light per area. The Southern Hemisphere experiences Winter at this time because it is tilted away from
the Sun meaning sunlight hits indirectly – causing low arcs & giving it less light per are 0 in direct light feels weaker & is more spread out. 13. Within what latitudes can an observer see the Sun directly overhead? How did these latitudes get their names? Only within the tropics can the Sun be seen directly overhead – at 1
