THE SUN,The EARTH,THE MOON (andother space things!) 4th Grade Science Duncan Elementary
THE SOLAR SYSTEM The Sun is at the center of our Solar System, and 8 planets revolvearound the Sun in a circular or elliptical orbit. Our Earth is the third planet from the Sun, and the only planet in the Solar System with plants, animals, and people! Jupiter Mercury Earth Saturn Uranus Neptune Venus Mars
THE SOLAR SYSTEM AND THE MILKY WAYOur Solar System is a very small part of a VERY LARGE collection of stars, planets, and space, called the MILKY WAY GALAXY.The Milky Way Galaxy is a very small part of the UNIVERSE, whose size cannot be determined with certainty. THE UNIVERSE MILKY WAY GALAXY
LIVING THINGS ON SOLAR SYSTEM PLANETS? Because they are so close to the Sun, planets Mercury and Venus are too hot for plants, animals and people to live there. Because they are so far from the Sun, Jupiter, Saturn, Neptune and Uranus are toocold for most living things. Mars is colder than Earth, and various studies have been conducted to determine whether there are any living things on “the Red Planet”. Jupiter Mercury Earth Saturn Uranus Neptune Venus Mars
THE STARS IN THE SKY On a cloudless night, away from city lights (or using a telescope), you would be able to see millions of stars in the sky. Some stars are brighter and closer thanothers. These stars are so far away that the light from these stars took hundreds or thousands of years to reach the Earth. Some bright stars form a pattern called a CONSTELLATION that looks like a person, animal or thing. The most common one we see in our sky is the “BIG DIPPER” that looks like a large spoon or soup ladle.
OTHER INTERESTING THINGS IN THE SKY• At night, we can get a great view of the MOON, in one if its many phases (more about that later!)• Sometimes, we can see a METEOR flash through the sky and burn up as it approaches the Earth.• Earth is sometimes visited by one of several COMETS that make their way around the Sun.• At times, we may see a bright object that is a PLANET with sunlight reflecting off its surface.• …but you would need to look really hard to see an astronaut cat outside the orbiting International Space Station!
THE SUN The Sun is actually a large star. Because the Sun is closer to us than any other star, it appears as a ball of orange, yellow, or white light in the sky. The Sun’s bright light prevents us from seeing any other stars in the sky, and is so bright, we would hurt our eyes if we looked at it directly. Like most stars, the Sun is a large mass of hydrogen and helium gases that constantly“burn” and re-generate, giving off heat energy and light. The Sun’s energy keeps us warm. Its light helps us see things around us, and helps our plants to grow.
MORE FACTS ABOUT THE SUN About 860,000 Miles Wide! (about 35 times wider than Earth)• The Sun is 860,000 miles wide, so about 109 Earths could fit inside the Sun!• The Sun is about 93 Million Miles away from Earth.• The Sun does not have any air or water, and is too hot for anything to live there.• The Sun’s light takes 8 minutes to travel to Earth, at the speed of light which is 182,200 miles per second! (fortunately, its light is sent out constantly so we don’t notice any delay)• The Sun’s surface is rough, with flares, spikes, waves and storms happening all the time, and cooler areas known as sunspots appearing periodically.
REVIEW QUESTIONS!Please answer these questions which are based on the information we have covered about the SUN!1. Other than the Sun, what are other things we can see in the night sky?2. About how far is the Sun away from the Earth?3. How long does it take the Earth to go around the Sun?4. How much bigger is the Sun compared to the Earth?5. What is the name of the closest star to Earth?6. The Sun is part of a constellation. True or False ?7. We would hurt our eyes if we looked directly at the Sun. True or False ?8. The Sun’s surface is very smooth and consistent. True or False ?9. All of our Solar System’s planets revolve around the Sun. True or False ?10.Our Sun is the largest thing in the Universe. True or False ?11.We could live on the Sun, but would need lots of ice to keep our ice cream from melting. True or False ?12.Explain why the Sun is so important to us on Earth.13.What are the names of the other planets in our Solar System? Which planet is closest to the Sun, and which planet is furthest?14.Why can we have a warm day, without ever seeing the Sun shining?
SOME FACTS ABOUT EARTH• The Earth is shaped like a ball that is a little flat on the top and bottom (at the North and South Poles)• The Earth was formed millions of years ago as very hot rock, metals and gases.• The planet we call Earth has three parts: o The CRUST: Rains cooled the Earth’s hot exterior, and made it suitable for life. o The MANTLE: A middle layer of very hot rock -- when a volcano erupts, we see what the mantle is like o The CORE: The extremely hot molten center of the Earth• The Earth has an atmosphere that includes: o Air for us to breathe (though there is less air the further you go away from the Earth’s surface) o Winds that move warm and cold air across the surface o Clouds that hold moisture above the surface, and deposit rain on the surface o Ozone that protects us from the radiation energy given off by the Sun.
MORE FACTS ABOUT EARTH • Above the Earth’s atmosphere and out into space, there is ZERO gravity ; that is, there is no force to hold things down or prevent them from floating -- the Earth has gravity that keeps people and objects on the ground. • The Earth is about 7,900 miles in diameter , and about 25,000 miles around (in circumference) at the Equator . • Millions of years ago, the Earth was covered in ice, which eventually melted to form oceans, lakes and rivers. • Many geologists believe that all the land we see on the Earth today, at one time had been attached – but the land broke apart and drifted to their current locations. • The highest point on the Earth’s surface is Mount Everest, and the lowest points lie deep below our oceans.
We live on the EARTH, inMichigan, which is here EARTH CLIMATE FACTS This is the EQUATOR, which is an imaginary line at the middle of the EARTH. The equator is rather summer-like (WARM or HOT) all The NORTH POLE is at the “topmost” year-round.part of the EARTH, and the SOUTH POLEis at the bottom-most part. Both these places are winter-like (very COLD) all year-round.
EARTHCLIMATE FACTS Michigan is closer to the cold NORTH POLE than it is to the warm EQUATOR, so our temperatures tend to be much cooler than countries near the Equator.
EARTH CLIMATE FACTSMichigan can have cool days in the Summer and warm days inthe Winter, because of the winds on the Earth’s surface thatmay blow warm Equator air or cool North Pole air towards us.
THE EARTH’S ROTATION The Earth spins about an AXIS imaginary line called an AXIS that extends from the North Pole to the South Pole. The Earth spins one complete rotation (completely around) every 24 hours – which is ONCE EACH DAY. The Earth spins at a rate of about 1,000 miles per hour! …but like flying in an airplane, when everything moves at the same fast speed it seems like nothing is moving!!
THE EARTH’S 23oROTATION Orbit Path around the Sun NOT LIKE THIS 23o THE EARTH’S TILT: As you may have noticed in previous slides that the Earth is tilted relative to the path it takes around the Sun. The line from the North Pole to the South Pole is tilted at a small (but important) 23 degree angle.
DAY AND NIGHT ON EARTHThe Sun does not really move, so the Earth’s spin about its axis is what causes Day and Night to occur. TheSun rises in the Eastern sky and sets in the Western sky. Sunrise in the East (over the Atlantic Ocean)
THE EARTH’S REVOLUTION AROUND THE SUN About 93 Million MilesThe Earth travels in an orbit around the Sun. When drawn, the orbit pathlooks like an ellipse, and this is one REVOLUTION around the Sun. It takes 365 days and about 6 hours for the Earth to make one complete revolution around the Sun. This means that the Earth is moving around the Sun at a speed of about 66,600 miles per hour!
THE EARTH’S REVOLUTION AND “LEAP YEAR” About 93 Million Miles Since it takes 365 days and a few extra hours for the Earth to make onecomplete revolution around the Sun, we must account for these extra hours onour calendars… This is the reason for adding an extra day to our calendar every 4 years, called a “Leap Year”. Since February is a short month, we add 1 extraday (Feb 29th) to our calendars in February of a Leap Year (2012, 2016, etc. are Leap Years)
SEASONS and AMOUNT OF DAYLIGHT The Earth’s orbit around the Sun and the tilt of our Earth are the reasons we: (1) experience four seasons in Michigan – Winter, Spring, Summer and Autumn (Fall), (2) why our temperatures change during these seasons, and (3) why we have a greater amount of daylight in the Summer than we have in Winter. WE WILL EXPLORE THIS IN THE NEXT FEW SLIDES!!!
THE WINTER POSITION OF EARTH In this position, it is WINTER in Michigan and the rest of the United States, with the SUN’s rays coming to us at an angle and not warming us as muchas the direct sunlight that the Equator, and the countries below the equator are getting. Note that in Australia, while we are experiencing Winter, they are having a nice warm Summer!
THE WINTER POSITION OF EARTHDuring Winter, we see the Sun in the southern part of the sky, because Michigan is tilted away from the Sun at this time of year. In this “Winter” position within our orbit around the Sun, the amount of daylight is at a minimum -- it gets dark at around 5pm.Note that many people say “the days are getting shorter” in Winter, but every day is still 24 hours long! – what they mean to say is that the daylight amount is getting shorter!
Northern Sky Southern Sky Duncan Elementary School (A Blue Ribbon School!) WINTER POSITION OF THE SUN IN OUR SKY In the Winter position of our Earth’s orbit around the Sun, the Earth’s tilt causes North America (including Michigan) to be tilted away from direct sunlight, so the Sun appears in the southern sky (closer to the southern “horizon”).
THE SPRING POSITION OF EARTH In this Spring orbit position, the Earth’s tilt is starting to give Michigan more direct sunlight, so we are starting to warm up!Spring is in the air and the amount of daylight is increasing by a few minutes each day!
THE SUMMER POSITION OF EARTHIt’s SUMMER in the United States and North America! The Sun at the center of oursolar system starts to appear directly overhead (straight up in the sky) at noon time.The people south of the Equator, such as in Australia and the South Pole, experienceWinter at this time, when the Sun appears in their Northern sky. The Sun’s rays are approaching those southern areas at an angle so these areas are not as warm.
Northern Sky Southern Sky Duncan Elementary School (A Blue Ribbon School!) SUMMER POSITION OF THE SUN IN OUR SKY In the Summer position of our Earth’s orbit around the Sun, the Earth’s tilt causes North America (including Michigan) to be tilted into direct sunlight, so the Sun appears directly overhead.
THE SUMMER POSITION OF EARTH Here, it’s not only SUMMER for us in Michigan, but the day with the longest period of daylight, which is usually June 21st.South of the Equator, they experience the shortest amount of daylight!
THE AUTUMN POSITION OF EARTH The Earth is still rotating at the same 23 degree axis angle, but as its REVOLUTION around the Sun places it in this AUTUMN position, the amount of sunlight each day is slowly shrinking, and AUTUMN is coming!
THE AUTUMN POSITION OF EARTH In this position, AUTUMN is here in Michigan, and the temperature is starting to get “chilly”. South of the Equator, however, is experiencing springtime, as their temperatures are starting to increase and sunlight each day is getting longer.
SUMMARY: THE EARTH AND THE SEASONS In this picture, you see one full year, with a full revolution around the Sun. TheEarth keeps the same tilt throughout, therefore causing the Sun’s energy to cometo us more “directly” in Spring, more “straight-on” in the Summer, and at steeper angles in the Autumn and Winter.
SUMMARY: THE EARTH AND THE SEASONSThis is an animation of the seasons occurring over one calendar year…
REVIEW QUESTIONS!Please answer these questions which are based on the information we have covered about the SUN!1. Define “Rotation”, “Revolution”, “Axis”, and “Orbit”.2. What is the Equator, and is it hot or cold there?3. Where are the coldest places on Earth, (why are they so cold)?4. How long does it take Earth to make one full rotation?5. How long does it take Earth to make one full revolution around the Sun?6. Explain why we have a Leap Year every 4 years?7. What is the angle that the Earth’s axis is tilted?8. What is the main reason why Michigan does not get as warm in the Winter (i.e., why the Sun is in the Southern sky)9. What season do we get the MOST sunlight in a given day, and which season do we get the LEAST sunlight?10.The Sun rises in the __________ and sets in the __________ .11.The Sun moves across our sky because Earth is rotating. True or False?12.Name several of the things in Earth’s atmosphere.13.Why it is possible to have a warm day in Winter or a cool day in Summer?
THE EARTH AND ITS MOON Many planets in our Solar System have more than one moon. The Earth has just one Moon. Our Moon is a sphere of rock formed millions of years ago that acts as a “satellite” orbiting the Earth as the Earth itself orbits around the Sun.Our Moon takes about 28 days (4 weeks) to travel around the Earth, but since theEarth makes a full rotation once each day, the Moon appears to move across oursky slowly during each night. The Moon is about 250,000 miles away from Earth.
THE MOON’S PHASES Sometimes we see the Moon as a full round object in the sky (A “Full Moon”).However, at most times the Moon’s location relative to the Earth and Sun means that we see a only a portion of the Moon lighted and a portion (or all) of theMoon “not lighted” (covered in shadows). These different appearances are calledPHASES OF THE MOON, as you can see here over a month span (May-June 2005):
THE MOON’S ORBITAND ITS PHASESThe Moon’s phases have beengiven names – for example, “FullMoon” when the entire face of theMoon is illuminated for us to seeon Earth, and “New Moon” whenthe back half of the Moon isilluminated and we can barely seethe face of the Moon at all. Last Quarter Full Moon First Quarter New Moon Moon Moon
A FEW MORE OF THE MOON’S PHASES Astronomers and scientists have given names to a few other Moon phases, as shown here (Waxing and Waning Crescent and Gibbous Moon Phases):Waxing Crescent Waning Crescent Waxing Gibbous Waning Gibbous (or just (or just (or just (or just “Crescent”) “Crescent”) “Gibbous”) “Gibbous”) Moon Moon Moon Moon
SUMMARY: THE MOON’S PHASESThis picture shows the positions of the Sun, Earth and Moon, and the different Moon Phases in these positions. SUN
EXPLORATION OF THE MOON• Neil Armstrong and Edwin “Buzz” Aldrin of the Apollo 11 mission were the 1st and 2nd persons to walk on the Moon, on July 20, 1969.• The Moon has no atmosphere, nor oxygen and no plant life, so the astronauts needed special suits with air tanks.• The Moon’s surface has many large bowl-shaped pits called “craters”, probably from meteor hits.• The Moon’s has a much lower amount of gravity so our astronauts could jump long distances, and felt much lighter than on Earth. In fact, on the Moon they weighed 1/6 of their weight on earth (their Earth weight divided by 6).Q: If you weigh 60 pounds on Earth, howmuch would you weigh on the Moon?
SOLAR ECLIPSES Because of the way the Moon orbits around the Earth, the Moon sometimes moves into a position where it entirely (or partially) covers the Sun in the sky. This is called a “TOTAL” or “PARTIAL” Eclipse. Total Eclipse of the Sun (“Solar Eclipse”) with extremely bright light showing around the Moon(DAMAGING TO THE HUMAN EYE!)Note that partial solar eclipses occur somewhere on Earth every 18 months or so. Total eclipses at any given location on Earth are rare – they only occur in Michigan every 410 years or so!
LUNAR ECLIPSESOccasionally, the Earth casts its shadow on the Moon during the day, thuscausing the Moon to go from visible to shaded then back to visible again.
REVIEW QUESTIONS!Please answer these questions which are based on the information we have covered about the MOON!1. The first person to walk on the Moon was Neil _______________.2. The Moon is invisible (darkened completely) during the _________ phase.3. _______________ are bowl shaped pits found on the Moon’s surface.4. The Moon is Earth’s natural ______________ because it orbits the Earth.5. A person who weighs 120 pounds on Earth will weigh only _____________ pounds on the Moon.6. When the Moon blocks our view of the Sun, it is called an ____________.7. The Moon shines because of reflected light from the _____________.8. When the Moon appears as a sliver of white, we call it a ____________ Moon.ADDITIONAL LUNAR QUESTIONS: Who was the 2nd person to walk on the Moon? What was the name of the mission that sent the first astronauts to walk on the Moon’s surface, and what year did this mission take place? How many days does it take to see all the Moon’s phases? Also, draw a few of the Moon’s phases.
REVIEW QUESTION ANSWERS!1. The first person to walk on the Moon was Neil Armstrong .2. The Moon is invisible (darkened completely) during the New Moon phase.3. Craters are bowl shaped pits found on the Moon’s surface.4. The Moon is Earth’s natural satellite because it orbits the Earth.5. A person who weighs 120 pounds on Earth will weigh only 120/6 = 20 pounds on the Moon.6. When the Moon blocks our view of the Sun, it is called an eclipse.7. The Moon shines because of reflected light from the Sun.8. When the Moon appears as a sliver of white, we call it a Crescent Moon.ADDITIONAL LUNAR QUESTIONS: Who was the 2nd person to walk on the Moon? (Buzz Aldrin) What was the name of the mission that sent the first astronauts to walk on the Moon’s surface, and what year did this mission take place? (Apollo 11, in 1969) How long does it take to see all the Moon’s phases? (about 28 days)
MORE REVIEW QUESTIONS! Please answer the questions presented here, which relate to the SUN, EARTH and MOON. Circle S for Sun, E for Earth and M for Moon (all that apply)!1. Is basically round: S E M2. Not suitable for human life: S E M3. Rotates fully around once each day: S E M4. Have different shapes called phases: S E M5. Has an atmosphere and plant life: S E M6. Has a mantle and a core: S E M7. Is mainly made of the elements Hydrogen and Helium: S E M8. Is the largest item in our Solar System: S E M
REVIEW QUESTION ANSWERS!1. Is basically round: S E M2. Not suitable for human life: S E M3. Rotates fully around once each day: S E M4. Have different shapes called phases: S E M5. Has an atmosphere and plant life: S E M6. Has a mantle and a core: S E M7. Is mainly made of the elements Hydrogen and Helium: S E M8. Is the largest item in our Solar System: S E M
SUN, EARTH, MOON CROSSWORD CLUES DOWNACROSS 1. Saturn has many of these around its surface1. Mars color 2. Star pattern, the “Big ________”4. Phase showing most of the Moon’s surface 3. Earth takes about 365 days for one or these6. Planet between Venus and Mars 5. Planet near Neptune8. Collection of stars that looks like a thing 7. Earth makes one full _______ each day11. When we add a day to February 8. “Sliver” Moon phase12. Earth’s nearest star 9. Circling around Earth or around the Sun13. Aldrin or Toy Story’s Lightyear 10. Protective layer in the Earth’s atmosphere17. When the Moon blocks out the Sun 14. When the Earth casts a shadow on the Moon18. This circles Earth every 28 days 15. NASA mission to the Moon20. Lunar holes caused by meteor strikes 16. Planet too hot for living things24. The Moon is a natural _______ of Earth 19. A planet between the Sun and Mars27. Planet between Earth and Saturn 21. Apollo 11 moonwalker28. Earth spins about this imaginary line 22. Planet near Jupiter, and former car brand extending from pole to pole 23. Lies below Earth’s crust (and above fireplace)32. Apollo 11 moonwalker 25. Lands on this imaginary line receive more direct33. One of earth’s poles sunlight than anywhere else34. What keeps things from floating off – 26. Earth has 23 degrees of this Moon has less of this than Earth! 29. The Sun rises here36. Darkened Moon phase 30. Volcano output, evidence of Earth’s hot inner core 31. Needed to breathe, the Moon has none