Planets And Moons

Copernicus

(1550) one of the first "modern" scientists to propose a model for the solar system with the sun at the center (heliocentric model). Provided explanation for why Mercury and Venus stay close to the Sun and for retrograde motion.

Kepler

(1600) provided laws that describe the motions of the planets; planets move in an ellipse around the sun

Galileo

(1620) first to use a telescope; jupiter had four moons that formed its own "planetary" system and that Venus was illuminated by the sun (geocentric system wrong)

Daughter/ Fission theory

(George Darwin) during early formation of the Earth, rapid spinning caused part of the Earth to break off and form the moon. (moon is slowly moving further from earth; physically improbable b/c not enough centrifugal force)

Observations of the moon

1) The moon lacks a metallic core (depleted in Fe compared to Si and O) 2) The basalts on Earth and Moon have very similar ratios of oxygen isotope ratios, but these are different from those in chonditic meteorites 3) The collected moon rock lack water, volatiles and life and appears to have been formed at very high temperatures

Hartmann's theory

1975: moon formation occurs through an impact of an asteroid the size of mars; debris formed the moon (physically plausible)

What is the age of the solar system?

4.567 billion years old

Formation of solar system

5 billion years ago a cloud of gas began to contract under gravity. As the cloud contracted it rotated faster and flattened. Most of the mass concentrated in the center, created hot conditions which invited fusion in our sun. Some material was left behind, which *condensed* into rush that collided and formed large bodies by *accretion.* Eventually these proto-planets attracted most of the mass that was left behind in the solar nebula to form the basis of the solar system.

The sun contains ______ of all mass of the solar system

99.86%

AU

Astronomical Unit: the average distance between Earth and the Sun (~150 million km)

What happens to Mar's appearance when it retrogrades?

Becomes brighter and redder

Space Age

Began in 1957 with the launch of the first artificial satellite, the Russian Sputnik . Began a politically prestigious space race.

Maria

Darker, smooth regions on the moon (oceans in latin)

What is the largest of the inner planets?

Earth

Sister theory

Earth and Moon accreted in the same parts of the solar system; explains compositional similarities but does not explain lack of iron and volatiles on Moon

The interior of the Earth consists of a ______ core

Fe-Ni

What roman God is Mars named after?

God of war

Which roman god is Venus named after?

Goddess of love

The sun consists of mostly_____

H and He

What are the bulk composition classifications of meteorites?

Irons, Stones, and Stony-Iron

What are the Jovian planets?

Jupiter, Saturn, Uranus, Neptune

What roman God is Jupiter named after?

King of gods

Which planet(s) has a retrograde motion?

Mars and the outer planets

Earth

Mass: 1 Radius: 1 Density/density of water: 5.4

Jupiter

Mass: 318 Radius: 11 Density/density of water: 1.2

Sun

Mass: 330,000 Radius: 110 Density/density of water ?

Which planet is closest to the Sun?

Mercury

Which planet moves the fastest?

Mercury

What are the terrestrial planets?

Mercury, Venus, Earth, Mars and the Moon

What are the origin classifications or meteorites?

Primitive of Differentiated

Differentiation

a body has undergone a major physical or chemical change

Comet

a small body in the solar system rich in ices which begins to evaporate when close to the sun, creating a large dust tail.

Differentiated meteorites

achondrites: iron meteorites made of pure iron and nickel, show a crystal structure; stony-irons meteorites; stony meteorites made of basalt (from lava)

Primitive meteorites

chondrites: characterized by the presence of small rocky chondrules that are small droplets of condensed solar nebula material about 4.567 billion years old

Nucleosynthesis

fusion in stellar interiors and neutron-capturing in super nova explosions

The giant outer planets consist mostly of a layer of _______ in both gaseous and liquid form

hydrogen and helium

Newton

laid the foundation for classical mechanics that describes the motions of the planets around the sun; explain Kepler's laws

Terrae

more lightly colored and densely cratered regions on the moon (highlands)

The Capture theory

proposes the moon and earth were formed in separate regions of the solar system and that earth caught in moon in its gravitational field. does not explain compositional similarities; not plausible

The moon faces the earth with the ___side

same; during one orbit around the earth it spins exactly once on its rotation axis

Impact craters

surface of the moon has evidence of these, caused by impacts of meteorites

stars are formed from ______

the gravitational collapse of molecular clouds

Which roman god is Mercury named after?

The messenger