Astronomical subjects Kepler"s and Newton"s laws Moon Sun Planets
Asteroids, Meteors, Comets Solar system facts Stars Glactic terms
The Earth has 4 layers: crust, mantle, outer core
and inner core
Crust: the hard outer
layer that we live on
Mantle: molten rock
beneath the crust
Outer core: molten nickel
and iron surrounding the inner core
Inner core: solid nickel
and iron at the center of the planet
The Earth is fatter than it is tall
The atmosphere has 3 layers: troposphere,
stratosphere, and ionosphere
Troposphere: layer of
atmosphere where we live and where convection occurs
Convection is the rising of warm air
and the falling of cold air
Convection creates wind and weather
Stratosphere: layer of
ozone
Protects us from harmful rays
Ozone is made of 3 molecules of
oxygen
Ionosphere: layer where
ions collide with the atmosphere
Reflects some radio waves, but not TV
waves
Layer in which the auroras take place
The magnetic field
of the Earth is caused by the inner and outer core rotating in opposite
directions
All magnets have a north and south pole
Opposite poles attract while like poles repel
Astronomy is the study of everything that lies beyond the Earth's atmosphere
The celestial sphere
is an imaginary sphere surrounding the Earth
All stars and other planets are on the celestial sphere
It is a convenient way to pinpoint things in the sky
Has poles in the same place as the Earth's poles
Has an equator
Rotational Period: the time it takes something to rotate, on it's axis, 360 degrees or once around (1 day)
Revolutional Period: the time it takes something to orbit something else (1 year)
Ions: atoms that have lost or gained electrons and are therefore either positively or negatively charged
The temperature measurements are: Fahrenheit, Celsius, and Kelvin
Astronomy began with the Greeks
Geocentric Universe: the theory that the Earth is the center of everything
Galileo destroyed the geocentric universe theory
Plato's elements: earth, air fire, and water; the heavens are made of quintessence (god stuff)
Parallax: when moving, things closer appear to be moving faster than things that are farther away
Occam's Razor: the simplest explanation is usually correct
Heliocentric Universe: the belief that the sun is the center of everything, a belief of Copernicus.
Kepler's laws
The orbits of planets are ellipses with the Sun at one focus
Planets move faster when closer to the sun and slower when
more distant
The semi-major axis
of a planet is equal to its distance from the sun
It is measured in AU or astronomical
units
The Earth is 1 UA from the sun
Newton's laws
Objects at rest stay at rest and objects in motion, stay in a
straight line and at a constant speed, unless acted upon by and outside force
Force = mass X acceleration
For every force one body exerts on a second, the second
exerts an equal and opposite force on the first (for every action there is an
equal and opposite reaction)
A rainbow is also called a spectrum (plural: spectra)
Circular velocity: the speed an object needs to stay in orbit
Escape velocity: the speed an object needs to escape gravity
Moon
Maria: plains covered
with dry lava on the Moon
Highlands: oldest parts
of the Moon
Lunar Eclipse: when the
moon disappears because the Earth is directly between it and the Sun
Sun
The Sun has three layers:
photosphere, chromosphere, and corona
Solar Eclipse: when the
Sun disappears because the Moon is between the Sun and the Earth
Sunspots: whirling
fountains of hot gas that have come out of the interior of the Sun
Prominences: huge loops
of gases rising from the surface and extending far into space
Solar Flares: violent
eruptions of matter and energy that spew light and charged atomic particles into
space
Mercury
The second smallest planet
Almost no atmosphere
Heavily cratered
Named for the messenger of the gods
No moons
Venus
Lots of clouds
Many craters, volcanoes, and lava flows
3rd brightest object in the sky
Greeks associated the planet with the goddess of love
1 of 3 planets that rotate backwards, east to west
Mars
Has a desert-like surface with huge valleys and volcanic
mountains
It has a thin atmosphere in which huge dust storms can cover
an entire atmosphere
Has polar ice caps and seasons due to tilted axis
It's red color, it reminded the ancients of blood: hence they
named it for the god of war
It has 2 moons: Phobos and Deimos
Jupiter
The largest planet and it is a gas giant
Storms are common and the Great Red Spot has been raging for
more than 300 years
It has faint rings and possibly a rocky core
Roman Jupiter was the king of the gods and the planet's
stately movements probably inspired it's name
It has at least 18 moons
Saturn
The second largest planet, almost 10 times the size of Earth
It has many storms, but it's rings, made of billions of
articles of rock and ice, are it's most notable feature
Named for the god of agriculture and time
It has 30 moons
Uranus
The 2nd of 3 planets that rotates backwards
Tilted on it's side
Similar to the size of Neptune, about 4 times the size of
Earth
It has faint rings
Named for the Greek god of the sky
It has 21 moons
Miranda (one of the moons) is a jumble of shattered rocks. It
is believed that whatever hit Uranus and knocked it on
it's side, also hit Miranda, shattering it
Neptune
The outermost gas giant
It has faint rings
It's orbit is almost perfectly circular
Pluto occasionally crosses inside Neptune's orbit and the
planets switch positions from the Sun
It has 8 moons
Pluto
Is the smallest planet
It is the third planet that rotates backward
It was discovered by Clyde Tombaugh
Named for the god of the underworld
Charon (one of Pluto's moons) was named for the mythological
boatman of the underworld
Asteroid: any of a number of small bodies orbiting between Mars and
Jupiter
Irregular chunks of rock and metallic substances
Leftovers from the planets
Meteors: the luminous phenomenon seen when a meteoroid enters the atmosphere; commonly known as a shooting or falling star
Meteorite: a part of a mereoroid that survives Earth's atmosphere
Meteoroid: a small rock in space
Comets:
frozen gases and dust-like particles
They have three parts: nucleus, halo, and tail
They have orbits and the tail always points away from the Sun
The solar system is the sun and everything that orbits it
A planet is a big body of matter that orbits the Sun in a well-defined, stable orbit
Terrestrial Planet: rocky surfaced planets that are fairly small
Jovian Planet: gas giants with no distinct surfaces and allhave rings made up mainly of ice crystals
Geologically dead: no geological activity, like volcanoes or earthquakes
Meteorologically dead: no meteorological activity, like rain or wind
Magnitude: is
the ranking of the stars in terms of their brightness, with 1 being brighter and
6 being fainter
Absolute Magnitude: is the brightness of the
star at a set distance from the Earth
Apparent Magnitude: is how bright the star
looks
Stars
They begin as huge, cold dark spheres of gas and dust
As the cloud shrinks and temperature and pressure increase,
the ball begins to glow and then becomes a star
They have a lifetime of millions to billions of years
When the fuel is used up, there is a final burst in size and
brilliance, and the star either collapses or explodes into a
nova or supernova and
eventually disintegrates
Supernovas
Supernovas blast off most of their material, leaving behind a
tiny but incredibly compressed core called a neutron
star
The neutron star usually rotates very rapidly and sends out
beams of light, resulting in a blinking effect that has led
astronomers to call it a pulsating star or pulsar
Some supernovas may become black holes
Black holes are regions so dense that not even light can
escape their intense gravitational fields
H-R Diagram:
also called the spectrum-luminosity diagram
It divides the stars into distinct roups according to their
color (spectrum) and their magnitude or stellar brightness (luminosity)
Right ascension:
the longitude
Measured in degrees
Declination:
the latitude in the sky
Measured in degrees, minutes, and seconds
Glactic disk: the flattened region of gas and dust that bisects the galactic halo in a spiral galaxy
Spiral Arm: stars in a pin-wheel design apparently emanating from near the galactic center
Galactic Nucleus: small center high-density region of a galaxy
Galactic Halo: spherical region around and far above a spiral galaxy that contains very hot gas and the oldest stars
Spiral Galaxy: a galaxy with a distinct nucleus and one ormore spiral arms
Barred Spiral: those spiral galaxies with an apparent bar of stars running their nuclei
Elliptical: galaxies with a rather clearly defined, symmetrical shape, ranging from spheres to ellipses
Irregular: no distinct shape
Quasars: also
called quasi-stellar radio sources
Extremely distant
High energy objects thought to be the energetic cores of
young galaxies
Star Clusters:
groups of stars and multiple star systems
Stars in a cluster, similar to one another is age and
composition
Stars in a cluster are gravitationally bound to one another