Astro final

Star System

is a star ( or stars) and any object or plants that orbit around it

Star

Is a large sphere of gas that generates heat and light through nuclear fusion in its core

Planet

A spherical thing that orbit a star and has clear its orbit of smaller objects

Dwarf Planet

basically like a planet but hasn't cleared its orbit

Moons/Satellites

objects the orbit a planet

Asteroid

a small rocky object that orbits a star

Comet

small icy object that orbits a star

Galaxy

a large collection of millions and billions of stars all orbiting the same center of gravity

Cluster

group of galaxies

Galaxy Cluster

is a collection of tens of thousand of galaxies all held together by gravity

Galaxy Supercluster

is a large collection of tens of thousands of galaxy clusters held together by gravity

The Universe

is everything that ever was, is, or will be

Astronomical Unit (AU)

the average distance between the earth and the sun, 149,600,000

Light Pollution

is scattered, manmade light which outshines dim light from celestial objects

Asterism

is a pattern formed from brings stars

Constellation

region of the night sky; every star inside the boundaries belong to the constellation; there are 88 constellation

The Celestial Sphere

is the imaginary bubble surrounding the earth on which all celestial objects appear

Ecliptic

is the apparent path of the sun around earth

The Celestial Equator

the midway b/w the horizon and overhead point in the celestial sphere

Altitude

is the degree above the horizon

Direction

is the location in regards to north south east or west

Zenith

is the point directly above the observer at an altitude of 90 degree

North Celestial Pole

the path earth rotates around

Circumpolar Star

stars that are always visible in the sky; they never set

Right Ascension

Measure degrees east to west of the vernal equinox

Declination

measures degrees north to south of the celestial equator

Vernal Equinox

is the point where the path of the sun crosses the celestial equator

Arcminute

is 1/60th of a degree on the sky

Arcsecond

is 1/60th of an arcminute

Solstice

when earth is tilted directly towards or away from the sun

Equinox

hallway b/w solstices when the earth switches from pointing away to pointing towards the sun

Speed

how far in a certain amount of time

Velocity

both the speed and the direction

Acceleration

change in velocity

Vacuum Chamber

a chamber where there is no air resistance or friction

Mass

how much stuff makes up an object

Weight

the force of gravity pulling on an object

Momentum

mass times velocity

Net Force

overall force acting on an object

Newtons Second Law of Motion

f=ma

Momentum

can be exchanged b/w objects but the total amount stays the same

Angular momentum

can be exchanged b/w objects , but the total amount stays the same if there are no net torques

Perihelion

point in a planet's orbit that is closest to the sun

Aphelion

point in a planet's orbit that is furthest from the sun

Eccentricity

how squashed the elliptical orbit is, closer to 1 is unbound, closer to 0 is circle

The Geocentric Model

earth centered model

Model

is a conceptual representation

Theory

is a testable explanation for many observations and experiments

Retrograde Motion

earth is faster than mars in the orbit, when passing mars, it appears to slow down, move backwards then forward

Epicycles

are circles on circles, the movement in a solar system

Heliocentric Model

sun centered solar system, but not the center of the universe

Astronomy

actual science

Photons

particles of light

Particle-wave duality of light

light behaves both as particle and a wave simultaneously

Lens

curved material that refracts and focuses light

CCDs

Sensitive detectors od photons

Angular Resolution

measure of the sharpness and clarity of an image

Spectrograph

disperses light and records it on a detector

Spectral Resolution

the sharpness of detail that can be seen in a spectrum

Light curve

a plot of brightness versus time

Seeing

a measure of celestial objects blurring due to the atmosphere

Adaptive optics

corrects the scrambles of incoming light waves

Spring Tide

moon closest to the earth's orbit in alignment with the sun

Neap Tide

moon closest to the earth's orbit but not in alignment with the sun

Tidally locked

the time it takes for the moon to complete 1 full orbit around the earth is = the time it takes for the moon to rotate around itself

Lunar eclipse

Moon passes into earth's shadow

Umbra

full shadow

Penumbra

partial shadow

Solar Eclipse

moons casts a shadow onto the earth

Seismology

is the study of seismic waves and how they change to learn about the earth's interior

Mantle

medium density rock

Crust

low density rock

Lithosphere

solid lawyer of rock

Conduction

heat flows from warm areas to cold areas

Radiation

heat is released as light

Erosion

gradual breakdown or transport of rock

Scarp

crack caused by settling as a worm planetary body cools

Regolith

fine powder of pulverized rock covering the moon's surface

Subduction Zone

dense seafloor crust is shoved under lighter continental crust and recycled

Ridge

seafloor spending pulls apart the crust , allowing material to rise up and cool to form new crust

Hot spot

plume of hot mantle material

Great Red Spot

located in Jupiter

Orbital Resonance

recurring gravitational interaction usually due to orbits related by a ratio

Shepherd Moons

a pair of moons that keep a ringlet sharp and narrow

Nebular Theory

solar system is formed in a collapsing gas cloud

Nebula

region of gas and dust

Solar Nebula

region of gas and dust out of which the solar system formed

Planetesimals

planet pieces

Protoplanetary Disk

partially collapsed region of gas forming a stellar system

Hydrostatic Equilibrium

the balance of the tow Maine forces of the sun, outward force of radiation, inward force of gravity

Core

energy generated by photons buy fusing hydrogen atoms into helium

The Radiation Zone

region where energy is transported by the radiative force of photons from the core

The Convection Zone

region where energy is transported upward by convection

The Photosphere

the visible surface of the sun

The Chromosphere

beginning of the sun's atmosphere

The Corona

outermost layer of the sun's atmosphere

The Solar Wind

a flow of charged particle from the surface of the sun

Fusion

nuclei combine to form a new atom

Fission

the splitting of nuclei into smaller atoms

Sunspots

are cooler areas on the sun's surface