3. Rotation
Rotation is a spinning motion
around a central point or axis.
The planet Earth rotates every 24
hours on its tilted axis. We have
a day and a night in each 24 hour
period.
The Moon also rotates on its
axis, once every 28 days. That’s
why we only see one side of the
Moon from Earth. (Now space
probes have photographed the far
or dark side.)
4. Day and Night
The Earth rotates, or spins, on its tilted axis once every 24 hours, so 24 hours make up
a day and a night.
When the Sun’s light doesn’t reach our part of the Earth, we have night. When our part
of the Earth is in the sunlight, we have day.
The Sun appears to rise in the east because the Earth spins in a counterclockwise
direction (if you are looking down at the North Pole), so areas to the east become
illuminated before land farther west.
5. How long is day and night?
The length of daytime and nighttime vary within the 24 hour rotation.
Your location on Earth and the time of year determine how long day and
night are. In winter in the Northern Hemisphere, night is long and day is
short. In summer, the opposite occurs.
6. What is a revolution in terms of astronomy ?
A revolution (or orbit) is the motion of one body around another. The
Earth revolves around the Sun, as do the other planets.
The Earth’s revolution around the Sun takes one year or about 365 days.
The Moon’s revolution around the Earth takes about one month or 28
days.
7. Why do Earth’s seasons occur?
The Earth turns on an axis, which runs through its North and South
poles. This axis is tilted off-center by 23 degrees. The Earth rotates once
every 24 hours on this tilted axis. That’s why we have day and night.
The Earth revolves around the sun once every 365 ¼ days. During
this year-long revolution, the tilt of the Earth’s axis doesn’t change its
orientation with the Sun. Therefore, different points on the globe get the
Sun’s light at different angles and for different lengths of daylight
throughout the year. The light heats the Earth unevenly. That’s why we
have seasons.
8. When the Northern Hemisphere is tilted toward the Sun, we have
summer. When the Northern Hemisphere is tilted away from the Sun, we
have winter. When the tilt isn’t pointing toward or away from the Sun,
we have spring and fall.
9. The seasons are not the same all over the Earth. At the equator, there
are no real seasons because the light from the Sun hits the Earth at about
the same angle and for the same amount of time all year round. At the
poles, there are only two seasons, summer and winter. In summer, it is
light all the time, but in winter it is dark all the time.
In between the equator and the poles, there are four seasons: winter,
spring, summer, and fall. But, the seasons are reversed in the Northern
and Southern Hemispheres. When it is winter in the Northern
Hemisphere, it summer in the Southern Hemisphere. Spring and fall are
also reversed.
Northern
Hemisphere
Seasons
10. The seasons are reversed in the
Northern and Summer Hemispheres.
11. Works Cited for MCAS Science Review Slide Shows
"Alaska Photographer Ron Niebrugge." Alaska Photographer Ron Niebrugge. N.p., n.d. Web. 01 Feb. 2013. <http://wildnatureimages.com/>.
"Bugman123.com - Paul Nylanderâ s Web Site." Bugman123.com. N.p., n.d. Web. 01 Feb. 2013. <http://www.bugman123.com/>.
"Carl Linnaeus." Carl Linnaeus. N.p., n.d. Web. 03 Feb. 2013.
"CASES: (a Lesson Plan)." CASES: (a Lesson Plan). CASES, n.d. Web. 01 Feb. 2013. <http://cases.soe.umich.edu/plans.php?nav=showplan>.
"Earth Floor: Cycles." Earth Floor: Cycles. N.p., n.d. Web. 01 Feb. 2013. <http://www.cotf.edu/ete/modules/msese/earthsysflr/rock.html>.
"ENCHANTED LEARNING HOME PAGE." ENCHANTED LEARNING HOME PAGE. N.p., n.d. Web. 01 Feb. 2013.
<http://www.enchantedlearning.com/>.
"Engineering Design Process." Engineering Is Elementary®. N.p., n.d. Web. 03 Feb. 2013.
"Fitting Algae Into the Food Web." Fitting Algae Into the Food Web. N.p., n.d. Web. 01 Feb. 2013. <http://www.bigelow.org/edhab/fitting_algae.html>.
"Food Chains - Geography For Kids - By KidsGeo.com." Food Chains - Geography For Kids - By KidsGeo.com. N.p., n.d. Web. 01 Feb. 2013.
<http://www.kidsgeo.com/geography-for-kids/0162-food-chains.php>.
"Forms of Energy." EIA Energy Kids -. N.p., n.d. Web. 01 Feb. 2013. <http://www.eia.gov/KIDS/energy.cfm?page=about_forms_of_energy-basics-k.cfm>.
"GCSE.com: Revising Revision." GCSE.com: Revising Revision. N.p., n.d. Web. 01 Feb. 2013. <http://www.gcse.com/>.
"Global Trade Online - The World's Popular B2B Trade Marketplace." Global Trade Online - The World's Popular B2B Trade Marketplace. N.p., n.d. Web.
01 Feb. 2013. <http://www.1st-product.com/>.
"Heights Technology Blog." Heights Technology Blog RSS. N.p., n.d. Web. 01 Feb. 2013. <http://heightstechnology.edublogs.org/category/assignments-11-
12/>.
"How the Moon Works." HowStuffWorks. N.p., n.d. Web. 03 Feb. 2013.
"HowStuffWorks "Science"" HowStuffWorks. N.p., n.d. Web. 01 Feb. 2013. <http://science.howstuffworks.com/>.
"Investment." : Evolution of Human. N.p., n.d. Web. 03 Feb. 2013.
Merriam-Webster. Merriam-Webster, n.d. Web. 01 Feb. 2013. <http://www.merriam-webster.com/>.
"Patently Apple." 'Patently Apple' N.p., n.d. Web. 01 Feb. 2013. <http://www.patentlyapple.com/>.
"Photo Gallery: Erosion and Weathering." National Geographic. N.p., n.d. Web. 03 Feb. 2013.
"Science Project Ideas, Information and Support for Science Fair Projects." Science Project Ideas, Information and Support for Science Fair Projects. N.p.,
n.d. Web. 01 Feb. 2013. <http://www.scienceproject.com/>.
Siegel, Ethan. "Dark Matter in Our Solar System." Starts with a Bang. N.p., 25 June 2008. Web. 03 Feb. 2013.
"Solar Sam's® Innovations." Solar Sam's Innovations Home. N.p., n.d. Web. 01 Feb. 2013. <http://www.solarsam.com/>.
"StarChild: The Solar System." StarChild: The Solar System. N.p., n.d. Web. 03 Feb. 2013.
"Tools Incorporated - Broussard LA - Oilfield Downhole Equipment - Rental Tools - Directional Drilling Equipment - Stabilizers - Mudmotors." Tools
Incorporated - Broussard LA - Oilfield Downhole Equipment - Rental Tools - Directional Drilling Equipment - Stabilizers - Mudmotors. N.p., n.d.
Web. 01 Feb. 2013. <http://tools-inc.com/>.
"Visual Dictionary." Visual Dictionary. N.p., n.d. Web. 01 Feb. 2013. <http://www.infovisual.info/>.
"Water Resources of Georgia." USGS Georgia Water Science Center. N.p., n.d. Web. 01 Feb. 2013. <http://ga.water.usgs.gov/>.
