1. The Hemispheres

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Read the text and choose a word for each gap. After you check your answers, try to define each of the terms using your own words.

Hemispheres
Image in Wikimedia Commons under Public Domain

Any circle drawn around the Earth divides it into two equal called hemispheres. There are generally considered to be four hemispheres: Northern, Southern, Eastern, and Western.

The Equator, or line of 0 degrees , divides the Earth into the Northern and Southern hemispheres. The Northern Hemisphere contains North America, the northern part of South America, Europe, the northern two-thirds of Africa, and most of Asia. The Southern Hemisphere contains most of South America, one-third of Africa, Australia, Antarctica, and some Asian islands.

There are differences in the climates of the Northern and Southern hemispheres because of the Earth's seasonal toward and away from the sun. In the Northern Hemisphere, the warmer summer months are from June through September. In the Southern Hemisphere, summer begins in December and ends in March.

The Earth can also be divided into hemispheres along , or lines of longitude. The prime , or 0 degrees longitude, and the International Date Line, 180 degrees longitude, divide the Earth into Eastern and Western hemispheres. Many geographers consider the 20 degree west line of and the 160 degree east line of longitude as the Eastern and Western hemispheres. This calculation is made so that Africa and Europe are not .

The idea of Eastern and Western hemispheres has become politically and historically significant since European nations began colonizing North America and South America. In this context, the Eastern Hemisphere is sometimes called the "Old World," and the Western Hemisphere is called the "New World." However, the Western Hemisphere is a purely term and should not be confused with other mentions of the "western" world, which is often used to describe parts of Europe, North America and other world regions that share some economic, social, and cultural values.

Source: https://www.nationalgeographic.org/encyclopedia/hemisphere/

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Reflexión

Watch this video about why there are different seasons, then answer the questions below.


Video by California Academy of Sciences  on YouTube

1. Why does the Sun shine differently on Earth at different times of the year?

2. Why is winter weather generally cold?

3. When are days and nights about equal in length?

4. When does sunlight strike the Northern Hemisphere more directly?

5. Why is it that when it's summer in the Northern Hemisphere it's winter in the Southern Hemisphere?

Mediation

Your classmate did not understand the video about the Earth's seasons very well. Read the following article that contains information about the same topic and summarize it to him/her. When you summarize, take into account the following:

  • Skim the text to get a general idea of the topic
  • Delete unnecessary or redundant material
  • Find the main ideas in the text
  • Find or create a topic sentence
  • Substitute general or "umbrella" terms when appropriate (for example, trees instead of oak, maple, and pine)

Source: https://www.teachervision.com/summarizing 

THE EARTH'S SEASONS

A season is a period of the year that is distinguished by special climate conditions. The four seasons—spring, summer, fall, and winter—follow one another regularly. Each has its own light, temperature, and weather patterns that repeat yearly.

In the Northern Hemisphere, winter generally begins on December 21 or 22. This is the winter solstice, the day of the year with the shortest period of daylight. Summer begins on June 20 or 21, the summer solstice, which has the most daylight of any day in the year. Spring and fall, or autumn, begin on equinoxes, days that have equal amounts of daylight and darkness. The vernal, or spring, equinox falls on March 20 or 21, and the autumnal equinox is on September 22 or 23.

The seasons in the Northern Hemisphere are the opposite of those in the Southern Hemisphere. This means that in Argentina and Australia, winter begins in June. The winter solstice in the Southern Hemisphere is June 20 or 21, while the summer solstice, the longest day of the year, is December 21 or 22.

Seasons occur because Earth is tilted on its axis relative to the orbital plane, the invisible, flat disc where most objects in the solar system orbit the sun. Earth's axis is an invisible line that runs through its center, from pole to pole. Earth rotates around its axis.

In June, when the Northern Hemisphere is tilted toward the sun, the sun's rays hit it for a greater part of the day than in winter. This means it gets more hours of daylight. In December, when the Northern Hemisphere is tilted away from the sun, with fewer hours of daylight.

Seasons have an enormous influence on vegetation and plant growth. Winter typically has cold weather, little daylight, and limited plant growth. In spring, plants sprout, tree leaves unfurl, and flowers blossom. Summer is the warmest time of the year and has the most daylight, so plants grow quickly. In autumn, temperatures drop, and many trees lose their leaves.

The four-season year is typical only in the mid-latitudes. The mid-latitudes are places that are neither near the poles nor near the Equator. The farther north you go, the bigger the differences in the seasons. Helsinki, Finland, sees 18.5 hours of daylight in the middle of June. In mid-December, however, it is light for less than 6 hours. Athens, Greece, in southern Europe, has a smaller variation. It has 14.5 hours of daylight in June and 9.5 hours in December.

Places near the Equator experience little seasonal variation. They have about the same amount of daylight and darkness throughout the year. These places remain warm year-round. Near the Equator, regions typically have alternating rainy and dry seasons.

Polar regions experience seasonal variation, although they are generally colder than other places on Earth. Near the poles, the amount of daylight changes dramatically between summer and winter. In Barrow, Alaska, the northernmost city in the U.S., it stays light all day long between mid-May and early August. The city is in total darkness between mid-November and January.

Source: https://www.nationalgeographic.org/encyclopedia/season/ 

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Why Does The Moon Look Upside Down From Australia?

Those of us who live in the Northern Hemisphere of our planet are used to a very specific view of the Moon, and, if you never travel outside of the Northern Hemisphere, journeying only to Europe, North America, Asia or the Arctic expanses, that view of the Moon would never change by very much.

However, once you move to the Southern Hemisphere, visiting South America, Africa, Australia or New Zealand, something will indeed seem off about the Moon. It's upside down in the sky, relative to what you'd be used to in the Northern Hemisphere. Likewise, if you're used to a Southern Hemisphere sky, moving to the Northern Hemisphere will turn the Moon upside down relative to what you're used to.

Many of the portraits of the Moon are oriented in the way you'd see them from the Northern Hemisphere. There's nothing fundamental about this orientation relative to the Southern Hemisphere orientation, but we've designated North as "up" for long enough that that convention has expanded outwards to the whole solar system. With that convention, it makes sense to display the Moon "right-side up," with the view from the Northern half of the planet.

The Moon is probably the most dramatic example of this in the night sky, simply because we know it so well, but it's not the only object that may appear odd in the Southern sky if you're used to the Northern view. Constellations do the exact same thing. Some Northern constellations are not visible in the Southern skies, but Orion, one of the brightest and easiest-to-spot constellations in the Northern winter sky, is visible from both hemispheres. And just like the Moon's change, Orion appears upside down, his head towards the ground instead of the rest of the stars overhead.

Source: https://www.forbes.com/sites/jillianscudder/2017/09/09/astroquizzical-upside-down-moon/#5cbe88e31231 


Video by the BBC  on YouTube

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