unit 1

If Earth's axis were not tilted, what would happen to the seasons?

There would be no perceived seasons on Earth and global day lengths and temperatures would be uniform.

Lines of longitude, also known as , are formed at right angles to the latitude lines.

meridians or meridian

Match the eras of geologic time with the corresponding dominant life forms.

Mesozoic--- Age of Reptiles Paleozoic--- Age of Marine Invertebrates, Fishes, and Amphibians Cenozoic-- Age of Mammals

Nuclear Blank______ is the process by which stars create elements that can have a greater atomic weight than lithium.

fusion

Stars create heavier elements through the process of nuclear

fusion

The Milky Way is a(n) composed of about 200 billion stars.

galaxy

Using the North Star to determine latitude

has been possible for the past 1000 years will not work forever because Earth's axis of rotation changes slowly over time

A scientific method used for determining the age of Earth is based upon the radioactive decay of

isotopes

The boundaries of geologic time units were first established by Blank______, and now a more accurate method, Blank______, is common.

the appearance and disappearance of fossil types; radiometric dating

If a hypothesis is supported consistently by different observations or experiments, it may be advanced to the level of a(n)

theory

Place the descriptions of Earth's mass extinction events in order, with the oldest event at the top and the most recent event at the bottom.

1. About 96% of all life on earth went extinct during this extinction event.2. About 50% of earth's species went extinct as a result of this event.3. This event killed off the dinosaurs as well as many other species.

Approximately Blank______ years ago, the Big Bang initiated the formation of the universe.

13.8 billion

The time of sunrise changes about one hour for each degrees of longitude on Earth.

15

The lunar month, whereby the Moon passes through all four phases, takes Blank______ days.

29.5 days

Which of the following is the scientifically accepted age of Earth?

4.5 to 4.6 billion years

The North Pole is located one-quarter of a circle in degrees latitude from the equator; thus its latitude is Blank______ degrees north.

90

Which of the following are true regarding a great circle?

All longitude lines form great circles. They include any circle on Earth's surface with its center at Earth's center. A great circle connecting any two points on Earth's surface defines the shortest distance between them.

Approximately 13.8 billion years ago, the Big initiated the formation of the universe.

Bang

On the summer solstice, the Sun does not set above the ArcticBlank 1Blank 1 Arctic , Correct Unavailable Circle (66.5°N) and does not rise above the AntarcticBlank 2Blank 2 Antarctic , Correct Unavailable Circle (66.5°S).

Blank 1: Arctic Blank 2: Antarctic

Greenwich Mean Time is also called Time as well as Time. (Use only one word per blank.)

Blank 1: Universal Blank 2: ZULU

As Earth and the other planets of the solar system cooled, the Sun's energy gradually replaced the heat of planet formation in maintaining their .

Blank 1: surface Blank 2: temperatures or temperature

Match the geologic time periods on the right side to their correct eras on the left.

Cenozoic--- Neogene, Quaternary Mesozoic--- Triassic, Jurassic, Cretaceous Paleozoic--- Cambrian, Ordovician, Silurian, Devonian, Carboniferous, Permian

Match the geologic era on the left with the correct animal group on the right.

Cenozoic---- Earliest hominids Mesozoic--- First mammals and first dinosaurs Paleozoic--- First fish and first reptiles

Match the type of matter to the correct description.

Dark matter-----This is thought to make up about 24% of all energy in the universe and does not interact with light. Normal matter-------This kind of matter is found in atoms and the world around us, making up only about 5% of the energy in the universe. Dark energy----This is thought to make up about 71% of all energy in the universe and to be causing the expansion of the universe.

Which of the following pieces of evidence indicate that Mars possessed water?

Data from soil and ice samples analyzed on the planet Sedimentary rocks with ripple marks

Which of the following processes added heat to early Earth?

Early Earth was bombarded by particles of all sizes, and some of that energy was converted to heat on impact. The growing layers of accumulated material resulted in the energy of compression being converted to heat.

The most probable (original) sources of the water in Earth's ocean are

Earth's mantle, some of which is brought to the surface through volcanic activity continual addition of water from outer space

The clock time is set to noon when the Sun is at its zenith above the prime meridian. This time is Blank______.

Greenwich Mean Time

What do the positions of the Arctic and Antarctic Circles at 66.5°N and 66.5°S, respectively, represent?

On the summer solstice, the Sun does not set above the Arctic Circle and does not rise above the Antarctic Circle.

Which of the following are necessary in order for you to find your position on Earth using GPS?

Precise measurements of distance between a receiver and four satellites Satellites to transmit a unique digital code to a ground receiver

Which of the following geologic timescale periods are part of the Cenozoic or "Age of Mammals"?

Quaternary

Drag and drop the definitions against the corresponding terms associated with the natural time periods.

Solar day- The average time for Earth to make one rotation relative to the Sun Sidereal day-- The measurement of a day on Earth based on making a complete rotation with respect to a far-distant point in space

The boundaries of the various units of geologic time were established mainly by which two methods?

The appearance or disappearance of certain fossils and radiometric dating

Which of the following of Earth's radii is greater?

The equatorial radius is greater than the polar radius.

What is the primary force that causes Earth to have a greater equatorial radius than the polar radius?

The force of rotation causes Earth to have a greater equatorial radius than the polar radius.

During the first few hundred million years after Earth was formed, its interior reached the melting point of iron and nickel. How did this process lead to even hotter temperatures occurring in Earth's interior?

The iron and nickel melted and migrated toward the center of the planet, and frictional heat was generated.

Which of the following are types of evidence that support the presence of oceans on two of Jupiter's moons?

There are induced magnetic fields around both moons, indicating that they both consist partly of strongly conducting material, such as seawater. The surfaces of the moons are ice covered, but heat is generated by friction from Jupiter's strong gravitational force.

During the winter solstice for the Northern Hemisphere, the Sun is directly overhead at which of the following locations?

Tropic of Capricorn

A nautical mile is equal to one minute of length of latitude or longitude at the equator.

arc

If Earth's overall size was scaled to the size of a basketball, then the distance from Earth's highest elevations to its deepest ocean depths would best be compared to the thickness of a(n) Blank______.

average human fingernail

The most widely accepted age of Earth is between 4.5 and 4.6 years.

billion

On the summer solstice, the Sun stand above the Tropic of . On the winter solstice, the Sun stand above the Tropic of .

cancer, capricorn

In the eighteenth century, a Blank______ was used to help determine longitude more precisely on ships.

chronometer

Which of the following pieces of technology had to be developed in order to calculate longitude accurately?

clocks

Galaxies are generally found in groups called Blank______

clusters

The most probable (original) sources of the water in Earth's ocean are

continual addition of water from outer space Earth's mantle, some of which is brought to the surface through volcanic activity

A half-life is the time over which one-half of the atoms of a radioactive isotope

decay

Over 71% of the universe is dark . The remainder is dark matter and normal matter.

energy

Geologic time is divided into four major : the Hadean, Archean, Proterozoic, and Phanerozoic.

eon

______ are generally found in groups called clusters.

galaxies

A(n) is composed of clumps of stars, and one example is the Milky Way.

galaxy

The four eons: the Hadean, the Archean, the Proterozoic, and the Phanerozoic, collectively make up what scientists refer to as Blank______ time.

geologic

Any circle at Earth's surface with its center at Earth's center is called Blank______.

great circle

A Blank______ is the time over which one-half of the atoms of a radioactive isotope decay.

half-life

If a(n) Blank______ is supported consistently, it may be advanced to the level of a theory.

hypothesis

The 180 degree longitude line approximates the Blank______.

international date line

GPS (Global Positioning System) navigation is widely used because Blank______.

it is worldwide now and extremely accurate

Because lines of rotate with Earth, 360 degrees in twenty-four hours, it is necessary to know the time of day and the position of the Sun or the stars relative to one's line.

longitude/meridian

Two potential sources of water on Earth include the and continual addition from outer space by icy comets.

mantle

A struck the planet just two and one-half years ago, killing 96% of all life.

massive extinction

The topographic relief of Earth's highest elevations and greatest depths is Blank______ compared to the overall size of the planet.

minor

Which of the following time periods is based upon the lunar cycle?

month

A(n) Blank______ is equal to one minute of arc length of latitude or longitude at the equator.

nautical mile

A rotating interstellar cloud of gas and dust is referred to as a Blank______.

nebula

The origin of our solar system is attributed to the collapse of a single, rotating interstellar cloud of gas and dust known as a(n

nebula

A light-year is equal to the distance light travels in Blank______.

one-year

Approximately 5 billions years ago, Blank______ was formed.

our solar system

The evolution of photosynthetic organisms on the early Earth resulted in an increase in the levels of the gas in its free or "pure" form.

oxygen

The most important gaseous element to accumulate in Earth's atmosphere, which had to await the evolution of photosynthesis in order to exceed its loss to space, is Blank______.

oxygen

Lines of latitude, also known as , are referenced to the equator.

parallels

In the lunar month, the Moon Blank______.

passes through its four phases

We use isotopes to determine the age of a rock unit using dating. This also helped us determine the age of Earth.

radiometric

Earth did not form a perfect sphere because it on its axis.

rotates

Old maps are accurate in their north and south depictions of Earth's surface, but many are badly distorted by their east and west dimensions of geographic forms. This is because Blank______.

sailors have been able to calculate latitude since ancient times

The Global Positioning System uses a group of as reference points for calculating positions on Earth's surface with an accuracy of a few meters.

satellites

Earth's tilt of 23.5 degrees as it orbits the Sun is responsible for the , which occur in both the Northern and Southern Hemispheres at opposite times of the solar year. (Hint: The answer is just one word.)

seasons

The Sun is directly over the two tropics, Cancer and Capricorn, at two times during the solar year. These two dates are called Blank______.

solstices

A galaxy is composed of clumps of Blank______.

stars

Match the seasonal marker with the correct positioning of the Sun relative to Earth.

summer solstice--- The Sun stands above the Tropic of Cancer. winter solstice---The Sun stands above the Tropic of Capricorn Autumnal and vernal equinox---- The Sun stands above the equator.

The major changes in the state of the universe that occurred immediately after the Big Bang were in Blank______ and Blank______.

temp and size

Lord Kelvin based his estimate of Earth's age on Blank______, but his results were way off compared to modern-day methods of dating.

temperature

If our galaxy has a thickness of about 1000 light-years, this is equal to Blank______.

the distance that light can travel in a single year multiplied by 1000

It is necessary to know the time of day and the position of the Sun or the stars relative to one's longitude line because Blank______.

the longitude line rotates with Earth, 360 degrees in twenty-four hours

Earth has been divided into time Blank______ that are 15 degrees of longitude wide, although some adjustments have been made when necessary to follow political boundaries for the convenience of people living in those areas.

zones

A sidereal day is about Blank______ than the mean solar day.

4 min shorter

Our solar system formed approximately Blank______ years ago.

5 billion

The Phoenix Probe landed on Mars and collected soil and ice samples that confirmed the presence of water on Mars.

true

The Big Bang is the currently accepted theory about the origin of the Blank______

universe

To determine the age of Earth using radiometric dating, one must Blank______.

use radioactive isotopes

The is the time required by Earth to complete one orbit about the Sun.

year or 365 days

Latitude can be calculated by measuring Blank______.

your angle in reference to the bright star, Polaris

The Sun is at Blank______ when it is at its highest elevation above a reference longitude.

zenith

When the Sun is at its , it is at the highest elevation above a reference longitude.

zenith

Match the inner and outer planet groups of our solar system with the correct characteristics.

Inner planets--- Rich in metals and rocky materials Outer planets--- Rich in ices of water, ammonia, and methane

Is it alway possible to use the North Star to measure latitude on Earth?

Is it alway possible to use the North Star to measure latitude on Earth?

The strong tidal influence of along with the magnetic measurements made by the Galileo spacecraft are strong evidence for oceans on the moons Europa and Callisto.

Jupiter