Chapter Two Earth and Space

Pluto

________ does not meet the last part of the definition and was considered a founding member of a new class of objects- dwarf planets.

Doppler effect

________ is the apparent change in the frequency of sound waves or light waves due to the motion of a source relative to an observer; for example, the change in frequency (pitch) of a siren from a passing police car.

Gravity

________ pulls debris together to form planets that revolve in a consistent direction around the star − Heavier, rocky planets closer to the star − Lighter, gas- rich planets farther from the star.

Astronomers

________ use the degree of "red shift "to determine the distance to far away galaxies more than 13 billion light- years (distance) from Earth.

Seasonal temperature contrasts

________ are due to the tilt of the Earths axis and the angle of the Suns rays Tilt= 23.5 degrees.

amount of solar energy

The ________ (insolation) reaching Earths surface depends on the angle the Suns rays strike Earth More heat is delivered by insolation where the Sun is directly overhead − As sunlight is distributed over a smaller area − Total annual insolation is the least at Poles, greatest at the Equator.

Galileo

________ used early telescopes to observe changes in the size and shape of Venus as it revolved around the sun.

Jovian Planets

________ are Large gas giants, much of the volume of the ________ is a thick atmosphere overlying oceans of liquid gases and is characterized by many moons and ring systems.

Heliocentric orbit hypothesis

________- a 16th- century idea suggested by Copernicus and Confirmed by Galileos early 17th- century observations of the phases of Venus- Changes in the size and shape of Venus as observed from Earth.

Geocentric orbit hypothesis

________- Ancient civilizations interpreted the rising of the sun in the east and set in the west to indicate the sun (and other planets) revolved around Earth- This remained the dominant idea for more than 2, 000 years.

Hydrogen

________ formed soon after the Big Bang.

Earths Crust

________ is composed of lighter elements (e.g., silicon, oxygen)

tectonic plates

Lithosphere divided into large slabs known as ________ − Plates move over Earths surface to produce earthquakes, volcanoes, mountain belts, and various features on the seafloor.

Terrestrial Planets

________ are Composed of rocks and divided into compositional layers.

Earths Mantle Core

________ is composed of heavier elements (e.g., iron, nickel) found in metallic meteorites.

Solar system

________- sun and surrounding planets.

Earth

________ is a small rocky planet that circles the sun, one of the hundreds of billions of stars making up the milky way.

Earths interior

________ can be divided into three major compositional layers − Crust- composed of lighter elements (e.g., silicon, oxygen) − Mantle- composed of rocks made up of 3 key elements (oxygen, silicon, magnesium) − Core- iron, and nickel − solid inner core − partially melted outer core is the source of Earths magnetic field.

Earths magnetic field

________ deflects the solar wind.

Fusion

________ would end when helium is used up The loss of the heat of fusion would form a smaller white dwarf star that will cool to a black dwarf star.

Earths size

________ is sufficient to produce enough gravity to hold a thick atmosphere of gases in place Atmosphere protects us from: Incoming asteroids /comets Harmful solar radiation (x- rays, UV)

Gravity

________ pulled together irregular clouds of gas and dust generated from the Big Bang to form galaxies (systems of stars)

The predominant element in the Sun is hydrogen, and then helium

by mass, it is 70% hydrogen, 28% helium, 1.5% carbon, nitrogen, and oxygen, and 0.5% all other elements

Solar system

sun and surrounding planets

IAU adopted a new definition of the term planet

A planet is an object that orbits a star and is massive enough (-400 km radius) for gravity to pull its material into an approximately spherical shape

Pluto does not meet the last part of the definition and was considered a founding member of a new class of objects

dwarf planets

Earths size is sufficient to produce enough gravity to hold a thick atmosphere of gases in place Atmosphere protects us from

Incoming asteroids/comets Harmful solar radiation (x-rays, UV)

Earths biosphere has altered the composition of the atmosphere to add oxygen and extract toxic carbon dioxide Atmosphere composition affects temperature

− Higher carbon dioxide content on Venus produces temperatures of 464oC

The composition of Earths atmosphere is just right to absorb enough heat to keep the average temperature of 15oC Greenhouse effect

− Water vapor and carbon dioxide (0.038%) gases absorb heat − Without the greenhouse effect, temperatures would be -18oC

Earths magnetic field protects Earth from the harmful solar wind that would strip away the atmosphere Magnetic field due to molten rocks in the outer core and relatively rapid planetary rotation

− Smaller planets or slowly rotating planets have lost heat and have weak magnetic fields