ASTRONOMY

how does the sun produce energy?

nuclear fusion, hydrofen atom → helium, (E=mc2)

how does energy move?

outward as light and heat

how do solar panels harness solar energy?

they use photovoltaic (PV) cells, sunlight hits panel → electrons move creating electric current, can be used immediately or stored in batteries

how does wind energy work?

sun heats earth enevenly, warm air rises, cool air sinks → wind

what causes tidal energy?

moons gravity, stronger during full/new moon

whats the moon?

a natural satellite that orbits earth

how are mooon phases caused?

the moon’s position relative to earth and sun

whats the solar eclipse?

moon is between sun and earth

whats lunar eclipse

earth is between sun and moon

whats umbra

darkest part of the shadow

whats penunbra

outside less shaded part caused by umbra

how are the inner planets?

small, rocky, close to sun

what are the inner planets?

mercury, venus, earth, mars

whats another term for inner planets?

terrestrial

how are the outer planets?

large, gaseous, far from sun

what are the outer planets?

jupiter, saturn, uranus, neptune

whats another term for outer planets?

gas/ice giants

whats the asteroid belt?

ring of rocky space objects between mars and jupiter

whats the kuiper belt?

belt of icy objects beyond neptune

whats the solar nebula theory?

solar system formed around 4.6B years ago, cloud of gas &dust collapsed due to gravity, sun formed at center, remaining material formed planets

asteroid

large rocky body orbiting sun

meteoroid

small rock in space

meteor

meteoroid burning in the atmosphere (shooting star)

meteorite

rock that hits earth

comet

icy body with tail when near sun

whats astronomical unit (AU)?

earth to sun distance

whats a light year?

distance light travels in one year

what are solar systems measured in?

AU

what are stars measured in?

light years

whats rotation?

spinning on axis, causes day/night

whats revolution?

orbiting another object, causes year

whats earths tilt and what does it do?

23.5 degrees, different sunlight angles, NOT distance from sun, tilt+revolution = seasons

describe the big bang theory

universe began as a hot dense point, expanded rapidly + still expanding

evidence for big bang theory

galaxy moving away(redshift), cosmic microwave background radiations, element abundance (mostly hydrogen and helium)