Download Comet: Small body of ice, rock, and cosmic dust loosely packed

Comet: Small body of ice, rock, and cosmic dust loosely packed together.
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Scientist think they are left over from planet formation.
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Comets pass close enough to the sun, solar radiation heats the water ice so that the comet
gives off gas and dust in the form of a long tail
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The comet tail can be either a ion tail or a dust tail. At times it could be both.
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Ion tail is electrically charged particle called ions. The solid center is called the nucleus
or the coma.
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Comet nuclei can range from less than half of a kilometer to more than 100 kilometers
Asteroid: Small rocky bodies with heavy metal in orbit around the sun
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They can be a few meters long to 900km long.
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Thought to be left over material from the formation of the earth
Meteorites: are small rocky objects hit the Earth all the time and do not cause much damage.
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A rock changes its classification based on its location:
Meteoroid – rock located in outer space
Meteor – rock burning up in the Earth’s atmosphere (Shooting Star/Meteor Shower)
Meteorite – rock that hits the ground
Tides: are periodic rises and falls of large bodies of water.
 Tides are caused by the gravitational pull of the moon and inertia.
 Most coastal areas see two high tides and two low tides every 24 hour period.
Tidal Range: The difference in height between consecutive high and low waters. The tidal range
varies from a maximum during spring tides to a minimum during neap tides.
High Tide: Tide at its highest level
Low Tide: Tide at its lowest level
Spring Tide: When the moon is full or new (14 days), the gravitational pull of the moon and sun
are combined
 A Spring tide occurs when the moon’s gravity and the sun’s gravity pulls on the water.
 At these times high tides are VERY HIGH and low tides are VERY LOW.
Neap Tide: During the moon's quarter phases the sun and moon work at right angles, causing the
bulges to cancel each other.
 These tides usually produce a much smaller difference between high and low tide.
Eclipse: occurs when one object gets in between you and another object and blocks your view
Lunar Eclipse: An eclipse in which the moon appears darkened as it passes into the earth's
shadow.
Solar Eclipse: An eclipse in which the sun is obscured by the moon.
Annular Eclipse: An eclipse of the sun in which the edge of the sun remains visible as a bright ring
around the moon.
Why don’t we have eclipses every new and full moon? If the Moon's orbit around the Earth were in the
same plane as the Earth's around the Sun (the ecliptic,) we would indeed have a monthly eclipse.
However, the Moon's orbit is inclined about 5 degrees to the Earth's orbit. The Moon passes through the
ecliptic only twice a month at a pair of points called the nodes. The rest of the time the Moon is either
above or below the plane of the Earth's orbit and does not pass directly through the Earth's shadow.
Waxing: the moons illuminated area is increasing.
Waning: the moons illuminated area is decreasing.
Satellite: a natural body that revolves around a planet and is also called a moon
Phases: Depending on the location of the moon in its orbit around the Earth, different parts are
illuminated. We give each phase a term.
Draw and label the phases of the moon in correct
order:
Summer Solstice: the day of the year when the Sun is above the horizon for the longest amount of time, around
21st June in the northern half of the Earth and 21st December in the southern half
Autmunal Equinox: happens around the 22nd or 23rd of September. Because the sun is directly
over the equator there is a roughly equal amount of daylight and darkness over the entire planet
during each equinox. (Start of Fall)
Winter Solstice: the day of the year when the sun is above the horizon for the shortest amount of time, around 21st
December in the northern half of the Earth and 21st June in the southern half
Vernal Equinox: happens around the 21st of March. Because the sun is directly over the equator
there is a roughly equal amount of daylight and darkness over the entire planet during each
equinox. (Start of spring)
Why do we have seasons?
1. The axis of the Earth is tilted approximately 23.5° in reference to the Sun and the Earth's
orbit. The tilt of the Earth always points in the same direction no matter where it happens to be
positioned in its orbit.
2. Earth rotates about its axis.
3. Earth revolves around the sun.
Draw the seasons: