Warm-up -Take out your science notebooks. -In the notes section, on a blank sheet of paper complete the following activity. -Draw the diagram. Fill in the correct phases of the moon as seen from earth. Label each phase. Sun Earth

2 Eclipses and Tides

Intro The Moon orbits at an angle with respect to the Earth’s orbit around the Sun. 3 Ecliptic plane Moon’s orbital plane

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Eclipses Two kinds: Solar and Lunar 5

Vocabulary Umbra - is the innermost and darkest part of a shadow, where the light source is completely blocked. An observer in the umbra experiences a total eclipse. Penumbra -is the region in which only a portion of the light source is blocked. An observer in the penumbra experiences a partial eclipse. 6

Solar Eclipse When the Moon’s shadow covers part of Earth Moon is in between Sun and Earth When viewed from Earth, moon covers part or all of sun Only happens at New Moon 7

Total Solar Eclipse Observers in the “umbra” shadow see a total eclipse (safe to view the Sun); can see the corona Those in “penumbra” see a partial eclipse—not safe to look directly at Sun Only lasts a few minutes Path of Totality about 10,000 miles long, only 100 miles wide 8

Photo of a Total Eclipse 9

Upcoming Solar Eclipses May 10, 2013, annular eclipse—not visible in USA Next Total Solar Eclipse in continental USA—August 21,

Eclipses Lunar eclipse: A lunar eclipse occurs when the moon passes through the shadow of the earth. Can be partial or full eclipse 11

12 When the Earth’s shadow covers the Moon, we have a lunar eclipse

Why is the Moon red during an eclipse? The Earth’s atmosphere filters some sunlight and allows it to reach the Moon’s surface The blue light is removed—scattered down to make a blue sky over those in daytime Remaining light is red or orange Some of this remaining light is bent or refracted so that a small fraction of it reaches the Moon Exact appearance depends on dust and clouds in the Earth’s atmosphere 13

Upcoming Lunar Eclipses Apr. 25, 2013, Partial eclipse (not visible in US) May 25, 2013, Penumbral eclipse Oct. 18, 2013, Penumbral eclipse Apr 15, 2014, TOTAL ECLIPSE –visible here 14

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16 Sun Moon Earth

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Tides Tides: alternating rise and fall in sea level produced by … gravity of the moon. In one day: 2 high tides, 2 low tides The Moon’s gravity tugs on the Earth. It pulls the most on the part of Earth closest, which raises the oceans. It pulls the least on the part of Earth that’s farthest, which allows the oceans and atmosphere to be further from the Moon (and higher) The Sun’s gravity does the same thing, but to a lesser extent. 19

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Season Vocabulary Seasons – A pattern of temperature changes & other weather trends over a year.

Season Vocabulary Equator – Imaginary line which separates the Northern from the Southern Hemisphere

Earth rotates around an imaginary line running through its center called an axis of rotation. The ends of the axis are the north and south poles. Earth turns on its axis once in 24 hours. Earth’s rotation is reason for day & night The Earth is tilted at about a 23 ½ degree angle from its orbit around the Sun. Reason for the seasons: Earth’s tilted axis and orbit

Season Vocabulary A revolution is the motion of one object around another once. It takes one year for Earth to make one revolution around the Sun or 365 ¼ days. Leap year every 4 years – add up ¼ days A rotation is one complete spin or turn on an axis. One rotation takes 24 hours.

Season Vocabulary Solstice – Period of time when one hemisphere gets its maximum area of sunlight, while the other hemisphere gets its minimum amount; the time of year when days are either longest or shortest and the angle of sunlight reaches its maximum or minimum. Winter & Summer Solstice– usually 21 st of December and June Winter: Earth is closest to the sun in December but Northern Hemisphere is tilted away – colder temperatures/shorter days Summer: Earth is furthest from the sun in June but Northern Hemisphere is tilted toward the sun – hotter temps/longer days

Equinox – Period of time in an orbit in which sunlight shines equally on the Northern Hemisphere and the Southern Hemisphere; a time of year when daylight and darkness are nearly equal for most of the Earth. (Happens twice a year). Spring & Fall – March & September

Date & Time of Solstices & Equinoxes in 2013 Equinoxes:March :02September :44 Solstices:June :04December :11

Planet Vocabulary Nebular Theory –our solar system developed from cloud of dust and gas Inner or rocky planets - Terrestrial Cratered Volcanism Closer to sun – gasses burned away Outer planets Gas giants Called Jovian planets 29

Distance is measured in miles, kilometers and astronomical units (abbreviated as AU = distance from Earth to the sun or 93,000,000 miles which equals 1 AU) Rotation – some have a retrograde rotation which means it spins backwards from all the other planets rotations Revolution – time it takes to orbit once around another object 30

Ellipse – elongated oval shape Temperature – measured in Fahrenheit, Celsius and Kelvin Greenhouse effect – trapping of gasses which doesn’t allow heat to escape – temperatures are extreme 31

Meteoroids, meteors & meteorites – chunks of rock & metals – range in size – called a meteoroid when in space, meteor when it enters Earth’s atmosphere and a meteorite when it hits Earth’s surface Asteroid – Large chunks of rock and various metals – range in size from a baseball to house-sized to almost dwarf planet size (Ceres is over 500 miles long) Asteroid Belt which is an areas that is in between Mars and Jupiter Comets – called dirty snowballs – made up of ice, dust & rock. Have an orbit that they follow. Very elliptical. Oort Cloud as well as Kupier Belt contain millions of comets. 32