20. Explain why seasons on the Earth cannot be due to the different distances of the Earth from the Sun as it orbits. There are 2 reasons given in the book. -Earth has seasons because its axis is tilted, during winter the earth is more tilted towards the sunlight, so less energy falls on each sq meter on the ground each second, this is the main reason why it is hotter in the summer and colder in the winter 21.When the North Pole is tilted towards the Sun, describe the seasons in the Northern and Southern Hemisphere. What are the seasons like when the South Pole is pointed towards the Sun? When the northern hemisphere is tilted towards the sun, it is experiencing summer, but it is winter in the southern hemisphere. When the south is pointing towards the sun, it is summer, and northern is winter During summer, the earth’s surface at your location is more nearly perpendicular to the incoming sunlight so the energy is more intense, more energy falls on each sq meter of the ground each second. 22. Describe what would happen to seasons on Earth if the Earth’s rotation axis had no tilt. We would have the same seasons north and south hemisphere 23. When is the Sun highest in the sky – summer or winter? Summer Explain how the altitude of the Sun can cause temperature differences? Sunlight strikes the ground more directly during summer than during winter 24. What does the name equinox mean? It means equality of day and night 12 hours each. Explain why the name equinox makes sense. It comes from the latin term with direct translation to (equal night) 25. For each question, answer whether it describes: Summer Solstice, Winter Solstice, Autumnal Equinox, Vernal Equinox. Some will have two answers.a. Sun is highest in sky when it crosses meridian Summer solstice/ june 21 b. First day of winter in Northern Hemisphere Winter Solstice/ dec 21/shortest day of the year c. Occurs around June 21 in Northern Hemisphere Summer Solstice d. Start of fall in Northern Hemisphere Autumnal equinox/ sep 22 e. 12 hours of daylight everywhere on Earth. Vernal equinox? 26. Explain why leap years are necessary to keep our Gregorian calendar lined up with the tropical year. To make up for that fraction of a day because the tropical year has approx ¼ extra day/ with an extra day in feb, this prevents the seasons from becoming out of sync with the months 27. Explain why it is always cold near the North and South Pole. Why are regions near the Poles sometimes called the “Land of the Midnight Sun”? In these regions, the sun is above the horizon 24 hrs/day for part of the year, earning this nickname. There is an equally long period during which the sun never rises and the nights are 24 hrs long. The sun never rises very high in the sky at these latitudes so the sunlight is never very direct. 28. Explain what it means to be part of the tropics on Earth. Is Los Angeles (Latitude = 34oN) in the Tropics? Explain. LA is not in thetropics. A band between latitude 23.5 south and 23.5 north is called the tropics 29. Will the north celestial pole always be near Polaris? Explain. No because eventhough its slow and takes 26,000 years for the north celestial pole to make one trip around a large circle, in the past thousands of years ago, you would find that the northern sky does not appear to rotate about a point near polaris, but instead the stars rotate about another point on the path. The celestial equator is perpendicular to earth’s axis, therefore as earth axis wobbles, the celestial equator must also wobble. As it wobbles, the locations where it crosses the ecliptic-the equinoxes- change as well. Precession of the equinoxes 30. T/F: We always see the same side of the Moon from the Earth. The moon does spin on its axis like earth and it spins at the same time, thats why we see the same side of the moon all the time 31. Does the moon rotate? Explain why or why not. What is synchronous rotation? That is, the moon rotates, or spins on its axis, in the same length of time it takes to orbit Earth. 32. Is the “dark side of the Moon” real? In other words, is there a part of the moon that is never lit? Explain. The moon rotates on it’s axis ONCE in the same time it takes to orbit us ONCE. no both sides get equal light, its justsynchronous rotation that prevents us from seeing the other side (the far side) 33. For each phase, describe how much of the Moon appears lit: a) New moon - it appears completely black, because the other side that is facing the sun is illuminated b) Crescent- a sliver of its illuminated half c) Quarter- we see half of the moon lit d) Gibbous- more than half of the near side(the side that we always see and facing us) is illuminated e) Full- we see the entire near side of the moon 34. What do the terms waxing and waning mean?  waxing means growing in size -waning means becoming smaller, 35. Describe the location of the Sun, Earth, and Moon during a solar eclipse. This occurs when the moon passes between earth and the sun/ order goes from sun, moon, earth 36. What is the difference between a total and a partial solar eclipse? A total eclipse occurs when the moon completely blocks the disk of the sun and it never lasts longer than 7 1/2 minutes. Order goes from sun, moon, earth. A partial occurs when the moon partially covers the disk of the sun37. Why are some solar eclipses annular instead of total? How does an annular solar eclipse look? An annular solar eclipse occurs when the moon is slightly farther away from Earth in its non-circular orbit, so it appears slightly smaller in the sky 38. Describe the location of the Sun, Earth, and Moon during a lunar eclipse. Order goes from sun, earth, moon/ the moon is entirely within the earth’s shadow 39. Which are more common to see – a total solar eclipse or a total lunar eclipse? Explain why. More ppl have witnessed a total lunar eclipse than a solar eclipse because you have to be located within the very narrow band of the moon’s shadow as it moves across the earth’s surface 40. What is in the center of a geocentric model of the solar system? What is in the center of a heliocentric model of the solar system? Which of these two models is correct? Geocentric is earth as the middle and heliocentric is sun Lecture notes -on