Astronomy Activities for Elementary Students: Observing the Moon and Constellations - Prof, Study Guides, Projects, Research of Astronomy

Download Astronomy Activities for Elementary Students: Observing the Moon and Constellations - Prof and more Study Guides, Projects, Research Astronomy in PDF only on Docsity! 1 ASTRONOMY ACTIVITIES FOR ELEMENTARY STUDENTS Patricia H. Reiff, Professor Dept. of Physics & Astronomy, Rice University All of the observing programs that I discuss below are best done with a parent. First, it makes certain the child isn't unsupervised after dark, and second, it piques the parent's interest in astronomy, too. Most of the activities involving stars are better done in the late fall or winter, when the Sun sets relatively early and the constellations are reasonably bright, even in the city. The best time to observe the stars is a clear night just after a cold front comes through - but be sure that the child knows to dress warmly! The Moon is easy enough to spot that a clear sky isn't necessary, and it is observable even in the daytime, so that it isn't necessary to restrict it to winter observations. Of course, it can't be overcast! THE MOON Most elementary students recognize the Moon, both at crescent and as a full Moon stages. Many students know that the Moon goes around the earth, but it is a simple month-long project to follow the Moon's path and see how its phases are influenced by its position in the sky relative to the Sun. First, find out from a calendar or the newspaper the day of the new Moon. Ask your students to go outside one hour after sunset (again, get the time from the newspaper) and look just above where the Sun set to see if they can see the thin crescent of the new Moon. Generally, the Moon will not be visible until the next day, but make it a game to see whether anyone can see it that day, and who can see it first the following day (or the next). Often with a narrow crescent moon, you can see the dark part of the moon, dimly lit by "earthshine". This is called "the old moon in the new moon's arms". The Earth, as seen from the Moon, also goes through phases, and when the Moon is new, the Earth as seen from the Moon is full, and so shines brightly on the dark Moon. Have them estimate how high above the horizon the Moon is (one fist at arm's length is about 10 degrees, good for adults and children). Have them note what time they first saw the Moon, and have them make a sketch of how it looked. Which way was the crescent pointing? (a cup or smile pointing up) For the next two weeks, have them look for the Moon at the same time every clear evening. Have them estimate its height above the horizon, and draw a sketch. One week after new Moon, the Moon should be half-full (first quarter) and will be nearly overhead at sunset. Each night it can be found farther and farther towards the east, until at full Moon, it should rise just as the Sun is setting. Can they see it at the same time the next night? When does it rise? (about an hour later). For the next week, have the students try to find the Moon in the sky in the early morning, first thing when they get to school (or before school with their parents, if there is time). The waning Moon should be visible in the west after sunrise, getting smaller and smaller as it becomes higher and higher in the sky. By the next week, it should be overhead at sunrise and down to half full again. Over the next few days it should become smaller and smaller, and farther to the east, closer to where the sun will rise. When is the last day you can see it in the morning? Now start looking in the evening again - when is the first time you can see it in the evening? That determines the Moon's orbital period (29 days). You can make a sketch for them to show them how the Sun's light changes the apparent shape of the Moon as it goes around the Earth. Note that half of the Moon is always lit by the sun… it’s just not always visible to us! This is also a great way to find planets, since the moon, traveling in the ecliptic, will over the course of the month pass nearby the planets that are up. For fall 2007, Jupiter and Mercury are in the evening sky; but Mars and Venus are in the morning sky. Which night is the Moon nearest Mars? Jupiter? Venus? The moon's path is a great way to trace out the ecliptic. Did you know 2 that a full moon in winter is high in the sky, like the sun in summer? A full moon in summer is low in the sky, like the sun in winter. Show the tilt of the Earth tilting away from the full moon if it tilts towards the Sun. CONSTELLATION IDENTIFICATION Use a planisphere (available from the Museum, telescope vendors, our Sky Tonight software, and/or Sky and Telescope) to dial up the sky for the early evening of the day you are interested in. Be aware that the times shown are for "sun time." Since we are west of the center of our time zone, the Sun and stars rise 21 minutes later than would be true for the center of the time zone. So, if you want to look at the sky at 8 p.m. CST, dial the planisphere to 7:40 p.m. If you want to look at the sky at 8 p.m. CDT, the daylight savings means another hour of correction: dial to 6:40. Since only the brightest stars are visible from Houston, make a simplified chart for your students with only the brightest stars on it (both sides). Use a time about an hour and a half after sunset. A subscription to Sky Calendar (available for $9 per year from Abrams Planetarium, Michigan State University, East Lansing, MI 48824) is economical, and provides you with a start chart (including the planets), plus daily finder charts for interesting events (i.e., conjunctions of Venus and the Moon). Or dial up the sky on our "Space Update" software (in the "Sky Tonight" section - note the different look directions). Practice first yourself to see which stars are identifiable from your own home. Have your student go outside with their parent(s) and try to find the star patterns. Have the parent(s) initial their star chart that they have identified two or more constellations. (The parents will enjoy helping with this homework.) Also try to identify 5 bright stars by name. Orion the hunter is very bright and easy to spot (a large rectangle with a row of three stars as a "belt" in the center). It is up essentially all school year - in the east in the fall semester, in the west in late spring. Can they tell which star is red (Betelgeuse)? Following the hunter is a very bright blue star: Sirius, the dog star. Sirius, along with Rigel from Orion (his right knee), Aldebaran in Taurus, Capella in Auriga, Pollux (one of the "twins" of Gemini), and Procyon (the "little dog") makes the "winter hexagon," easily visible in the city. Similarly, the "summer triangle" is visible in the late spring. ROTATION OF THE STAR PATTERN Observing the constellations near the north pole is the easiest way to teach that the stars rotate around "Polaris" (the pole star). Since we are at 30 degrees north latitude, Polaris is located 30 degrees above our Northern horizon. Unfortunately, Polaris itself is the only star visible in the Little Dipper from inside the city of Houston. Two other polar constellations are readily observable from Houston, and since they are on opposite sides of the north star, one or the other is always visible. The better-known constellation is, of course, the Big Dipper. Since it is located between 40 and 50 degrees from the pole, it is not always up in the sky. It is visible in Houston in the early evenings from the end of January (when it is low and to the right of the polestar, through the middle of September (when it is right-side up). At the end of April, it is upside down in the early evening. Recall that the last two stars of the bowl always point at the north star. Therefore, you can see the big dipper to watch the rotation of the sky, but only starting in February. Another constellation that can be used (and is a little easier, since it is closer to the pole) is Cassiopeia, the Queen. Her throne looks variously like a wide "W" (in late July), an angular "3" (August through the end of March). In the late spring and early summer it is below the horizon in the early evening, rising later in the night. (Play around with your planispheres to teach yourself how the stars change with the seasons.)