Randy's Corner
The solstice occurs in the month of December. This year the solstice falls
on December 21st. The solstices (winter and summer) and equinoxes (spring and
fall) are astronomical events that mark our seasons. Because of the tilt of
Earth's axis, the Sun appears to climb higher (in the summer) and sink lower
(in the winter) in the sky as viewed from our planet. A solstice is a time
when the Sun momentarily pauses in this apparent migration as it reaches the
greatest extremes of its "wanderings" and begins to "move" back in the opposite
direction. The word "solstice" comes from two Latin roots: "sol", which means
"Sun", and "sistere", which translates as "stand still".
The December solstice is the winter solstice in the Northern Hemisphere. The
situation is, of course, reversed in the Southern Hemisphere - where the December
solstice is the summer solstice. The solstice is commonly referred to as the
start of winter (or summer), but it is actually the midway point of the season
from an astronomical perspective. Since our planet's atmosphere and oceans
"store" heat, temperature extremes tend to lag behind the dates of
minimum (or maximum) heating by the Sun, so the coldest part of winter (or
hottest
part of summer) happens after the solstice.
Students often mistakenly believe that the seasons are caused by variations
in Earth's distance from the Sun. This misconception doesn't make sense when
one remembers that the seasons are opposite in the Northern and Southern Hemispheres
- why isn't it cold everywhere on the globe when the Earth is farthest from
the Sun? As Earth travels around the Sun in its elliptical orbit, its closest
approach
to our celestial furnace is in January (on the 4th in 2006), during the depth
of winter in the Northern Hemisphere.
To learn more about the solstice and seasons, check out these pages on
Windows to the Universe:
Some of the specific National Science Education Content Standards you might
want to touch upon while discussing the solstice and seasons with your students
include:
- Objects in the sky - The sun, moon, stars, clouds, birds, and airplanes
all have properties, locations, and movements that can be observed and described.
The sun provides the light and heat necessary to maintain the temperature
of the earth.
- Changes in earth and sky - Objects in the sky have patterns of movement.
The sun, for example, appears to move across the sky in the same way every
day, but its path changes slowly over the seasons.
Structure of the earth system - Oceans have a major effect on climate, because
water in the oceans holds a large amount of heat.
Earth in the solar system:
- The earth is the third planet from the sun in a system that includes the
moon, the sun, eight other planets and their moons, and smaller objects,
such as asteroids and comets. The sun, an average star, is the central and
largest body in the solar system.
- Most objects in the solar system are in regular and predictable motion.
Those motions explain such phenomena as the day, the year, phases of the
moon, and eclipses.
- Gravity is the force that keeps planets in orbit around the sun and governs
the rest of the motion in the solar system.
- The sun is the major source of energy for phenomena on the earth's surface,
such as growth of plants, winds, ocean currents, and the water cycle. Seasons result from variations in the amount of the sun's energy hitting the surface,
due to the tilt of the earth's rotation on its axis and the length of the
day.
Energy in the earth system:
- Earth systems have internal and external sources of energy, both of which
create heat. The sun is the major external source of energy.
- Heating of earth's surface and atmosphere by the sun drives convection
within the atmosphere and oceans, producing winds and ocean currents.
- Global climate is determined by energy transfer from the sun at and near
the earth's surface. This energy transfer is influenced by dynamic processes
such as cloud cover and the earth's rotation, and static conditions such
as the position of mountain ranges and oceans.
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Roberta's Corner
It's really exciting for us to see the number of Windows to the Universe Educators growing to over 900 teachers from around the world in two months! With ~230 teachers joining us from 60 countries ranging from Afganistan to Viet Nam, and ~675 from across the United States, we are successfully developing a global community of educators who are interested in the Earth and space sciences offered in an interdisciplinary context. This also offers the opportunity for community members to share insights with each other about how they handle specific topics in the classroom, needs, and tips on how to use Windows to the Universe and its imbedded resources in the classroom. We'd love to find out if you would be interested in a "Teacher's Corner", in which we could highlight information that you'd like to share with other Windows to the Universe Educators on these topics. Please take a few moments to fill out the survey - we look forward to hearing from you!
Jennifer's Corner
At the end of November, millions of turkeys are served on US dinner tables as part of Thanksgiving. Consequently, this is the month in the US when many people ask questions like, "How big a bird did you cook?".
Ask questions about life adaptation skills and evolutionary processes with our Bird Beaks activity - complete with an accompanying PowerPoint presentation and group and class handouts for data collection.
This activity uses very simple materials, is aligned to the National Standards (see activity for more details) and can be used for upper elementary through high school levels.
Lisa's Corner
Studying the rock cycle with your students? Make the connection between sedimentary rocks and environments by having students peruse the pictorial tour at Sedimentary Rocks Contain Clues to Ancient Environments. This collection of clickable “then and now” photos illustrates how different suites of sedimentary rocks form in different conditions such as quick moving rivers, murky swamps, and even coral reefs.
After exploring this section on Windows to the Universe, allow students to explore sedimentary rocks through hands-on activities such as
Making Sedimentary Rocks and Layers of Rock to further delve into NSES Content Standard D (Structure of the Earth System and Earth History).
Marina's Corner
The Northern Hemisphere is getting chilly as winter begins. And when it is cold, thoughts on staying warm come to mind! Get your students to talk about warm things on Earth! This is a good opportunity to talk about Volcanoes. Explore our Volcanoes pages in order to learn in detail how they form and erupt as well as how they can shape a landscape! Check out pages about volcano formation, volcanoes, and eruptions. Check out Lisa's corner (above) in order to further explore the rock cycle!
Julia's Corner
We have many educational games at our site and are constantly adding new ones. Most of these games are Java applets. Unfortunately, Microsoft has ended its support of Java in the Internet Explorer browser, so if you have Windows XP on your computer, you might not be able to play these games unless you download Java from Sun Microsystems. To do this, go to www.java.com and click on "Java Software Download".
Check out our new Jigsaw Puzzles! This game is created in Macromedia Flash instead of Java. We are planning to add more Flash games in the future.
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