Nitrogen (78%)

Oxygen (21%)

Argon (0.93%)

Carbon Dioxide (0.036%)

are all . . . 

• water in the atmosphere
• varying highs & lows depending on the regions

Evaporate¹

Atmosphere²

Condenses³

• microscopic solids in the air
• they provide solid surfaces on which H₂O molecules will condense

• dirt (dust) - clay particles
• pollen
• microorganisms
• volcanic ash
• pollution (soot)

Right¹

Left²

• cars & trucks
• power & industrial plants
• cows
• ships
• planes & jets
• trains
• cigarettes

are all . . . 

CFCs¹

Removing²

Forming³

Thinning⁴

• form as water molecules adhere to tiny solid particles floating in the atmosphere
• classified based on their shape & height

Grow Larger¹

Gravity²

• thin, whispy clouds 
• form @ high-altitudes 
• often portend a change in weather

• puffy blobular clouds w/ a flat bottom
• form @ low-mid altitudes 
• indicate unstable atmosphere

• layered clouds
• usually form @ low-alititudes
• can block out entire city

• daily chancge in atmospheric conditions
• controls biological activity & many natural processes

• average weather over a period of time (months, yrs, decades, millenia . . . )
• function of temp & precipitation
• determine types & abundance of plants & animals living in an area

Moist¹

Dry²

Cold³

Warm⁴

• Air masses formed:
• over ocean tend to be . . .
• over land tend to be . . .
• at high-altitude tend to be . . .
• at low-altitude tend to be . . . 

• cold air advances into an area occupied by warm air
• creates rapid adiabatic cooling & dangerous storms 

• cold front catches up to a warm front
• combined rain occurs from warm & cold fronts

• high-altitude & high-velocity wind flow above convection cells
• flow from regions of high pressure toward regions of low pressure

• used by astronomers to study celestial objects
• all gather electromagnetic radiation emitted from stars and other objects 

• comes in wavelengths of varying color
• spectrum can be used to determine its composition & surface temp.
• can inform whether celestial object is moving toward or away from Earth

Effect that informs astronomers if a celestial object is moving towards or away from Earth

• If shifted toward red = away from Earth
• Is shaded blue = toward Earth

• gather radio waves which penetrate through dust/gas clouds (nebulae) providing view of distant objects that aren't viewable w/ optical telescopes
• data goes through computer
• can get a detailed image
• record data 24/7

• vast grouping of stars, nebulae & planets, & a variety of minor objects
• held together by gravity so they travel together through space & time

cloud-like masses of young stars 

make up 10% of all galaxies

• pinwheel shaped composed of young & old stars (i.e. Milky Way)
• make up 30% of all galaxies 

• Protostar Phase
• Main-Sequence Phase
• Other Phases:
• Red Giant Phase
• Dwarf Phase

• mass of dust/gas atoms begin to contract toward center of mass generating heat from friction
• @ temp of 10,000,000^oF fusion occurs & star is born!

• consists of a central star that emanates electromagnetic radiation for surrounding smaller & cooler bodies
• including planets, their satellites/moons, other debris (asteroids & comets)
• cooler, solid objects held in orbits by combo of gravity & inertia 

• Inner Planets are called . . . & include:
• Mercury
• Venus
• Earth
• Mars
• Outer Planets are called . . . & include:
• Jupiter 
• Saturn 
• Uranus
• Neptune

• as planets formed so did the satellites (i.e. Jupiter)
• small satellites (originally asteroids) can be captured by a planet's gravity (i.e. Mars)
• planet is strucked by a large object, sending debris into orbit around planet where it condenses & coalesces to form a satellite (i.e. Earth's Moon)

• Protection from asteroid/comet impact
• Protection from harmful electromagnetic radiation
• Raise planet's surface temperature

small, rocky w/ thin atmospheres

include: Mercury, Venus, Earth & Mars

• smallest planet
• closest to the sun
• very hot (800^oF on sun-facing side & -200^oF on other side)
• very thin atmosphere
• has many impact craters 

• similar in size, density & mass to Earth
• very few impact craters 
• lots of shield volcanos
• no plate tectnoics = huge volcanos
• has fairly thick, CO₂-rich atmosphere (greenhouse effect: surface temp >900^oF)

• unique in solar system
• has . . . 
• land water
• plate tectonics (earthquakes & volcanoes)
• a narrow temp. range (132^oF - -90^oF)
• it's satellite is very large compared to it's planet

• known as the Red Planet 
• 3/5 the size of Earth
• thin atmosphere 
• 1% density of Earth's
• has . . . 
• polar ice caps that change w/ seasons
• canyons carved by liquid water in the past
• tall volcanoes & tiny satellites
• most likely can be a planet for human colonization

• very far from Sun
• composed mainly of gas (H & He) & ice
• includes: 
• Jupiter
• Saturn
• Uranus
• Neptune

• largest planet
• rotates rapidly
• stimulating rapid wind flow & huge, long-lasting storms
• has 63 satellites & faint rings

• 2^nd largest planet
• has . . .
• 56 satellites 
• largest - Titan
• a well-developed ring system

• has faint rings
• 1/3 of Jupiter's size
• it's orbital axis is parallel to ecliptic plane

• furthest planet from sun
• atmosphere's methane-rich
• makes planet blue in color
• has 13 satellites (i.e. Tritan) 

• small, icy bodies w/ elliptical orbits around sun
• includes Pluto
• exist in Kuiper Belt 
• along w/ comets

• large, rocky fragments of a former planet 
• most orbit in between Mars & Jupiter
• some orbit close to Earth & can cause major impact or extinction event

• composed of water & CO2 (ice & dust) 
• dirty iceballs originate from Kuiper Belt & beyond
• have wild elliptical orbits that can bring them close to the sun