space gr 9

speed of light

300 000 km/s or 10 trillion km in 1 year

astronomical unit

distance from earth to sun

1 AU = 150 000 000 km

parallax

apparent shift in position of an object due to change of view point

using angles and known base of the triangle created from the viewpoint, the distance from an object can be calculated

2 universe theories

expanding universe - universe is constantly and forever expanding from the big bang

oscillating universe - cyclic model/oscillating model is where the universe follows infinite self-sustaining cycles, each beginning with a big bang and ending with a big crunch

rotation

spinning on a single axis

revolution

the movement of an object all the way around another object

perigee

closest point in the moon’s orbit

apogee

farthest point in the moon’s orbit

perihelion

point in a planet’s orbit where it is nearest to the sun

aphelion

point in a planet’s orbit where it is fartehst from the sun

what is the tilt of the earth

23.5 degrees

why do we have seasons

because of earths tilt

big bang

proposed theory in 1948

very high temperatures

protons and electrions would move slow enough to attract together to form hydrogen, which then became helium

aristotle

thought earth was centre of the universe (geocentric)_

model looked like an onion skin

rest of solar system radiated outwards on concentric circles

ptolemy

geocentric

believed solar system was like a ferris wheel

each plant was a seat on the ferris wheel

wandering motion

copernicus

said wandering motion could be explained if the sun was the centre of the universe (heliocentric)

proved the sun was the centre

galileo

invented the telescope

viewed planets and sun through telescope

proved sun was the centre of universe

discovered moons orbited jupiter

kepler

mathematically proved that planets moved in elliptical orbits and not spherical ones

newton

discovered the law of gravity which helped explain how planets stayed in orbit

when was uranus discovered

1781

when was neptune discovered

1846

percival lowell

proposed idea of planet x in 1905

pluto

discovered in 1930 via telescope

dispute on whether it is planet x

some believed it was a moon or comet

voyager 1

launched in 1977, discovered jupiter’s big red spot

discovered new moons of jupier

saw that saturn had more rings than we thought

voyager 2

launched in 1979

found that uranus has rings and a magnetic field

neptune had dark spots and winds up to 2000 km/h

uranus is sideways

hubble space telescope

first space telescope

launched in 1990

could take pics w/out light pollution

first discovered the schumacher-levy’s comets jupiter hitting

sojourner

launched in 1997

explored surface of mars

meteroid

chunk of rocky material in space

meteors

meteroids that burn up in our atmosphere

‘shooting stars’

one tail

meteorites

meteors that land on earth

asteroids

very large meteoroids that can be found between mars and jupiter (asteroid belt)

leftover rocky material that never became a planet

comets

like meteroids but with with lots of ice

have ice tails that form when the sun melts its ice

move on a different plane

2 tails - dust and ice

ice tail is always perpendicular to where the sun is

which direction do sun/stars rise and set

rise in east and set in west

star maps aka…

planespheres

polaris

aka north star

aligned with earth’s axis

one star that does not move

ursa minor

aka little dipper or little bear

circumpolar constellation - never sets in northern sky

ursa major

aka great bear or big dipper

very common in northern sky

4 inner planets

terrestial planets

solid bodies and rocky surfaces

developed from small grains of dust that collided

outer planets

gas giants/jovians

big gas balls

solid core made of H or He

electromagnetic radiation

includes gamma rays, x-rays, ultraviolet light, visible light, infrared radiation, microwaves, and radio waves

sun diameter

1.4 million km

4 parts of sun

solar interior

visible surface (photosphere)

chromosphere

corona

photosphere

region of the sun that radiates energy to space

visible surface of the sun

layer of incandescent gas less than 500 km thick

grainy texture made up of small bright markings called granules, produced by convection

avg temp 6000 K

8 mins to earth light speed

chromosphere

first layer of solar atmosphere found directly above photosphere

relatively thin, hot layer of incandescent gases a few thousand km thick

contains spicules - narrow jets of rising material

corona

outer weak layer of solar atmosphere

temp at top of corona is more than 1 million k

solar wind is a stream of protons and electrons ejected at high speed from the solar corona

sunspot

dark spot on the sun that is cool in contrast to the surrounding photosphere

appear dark because they are cooler (about 1500 k cooler than surrounding surface)

prominences

huge cloudlike structures consisting of chromospheric gases

ionized gases trapped by magnetic fields that extend from regions of intense solar activity

solar flares

brief outbursts that normally last about an hour

appears as a sudden brightening of the region above a sunspot cluster

release huge amounts of energy - uv, radio, x-ray radiation

auroras

result of solar flares

bright displays of every-changing light caused by solar radiation that interacts with the upper atmosphere in the region of the poles

nuclear fusion

how the sun produces energy

converts 4 hydrogen nuclei into the nucleus of a helium atom

brightness

how much or how intense the light emitted from a star

2 types of brightness

Absolute Magnitude - the “true” brightness of the star

Apparent Brightness/Magnitude - Dependent on distance of stars where the closer stars appear brighter and farther stars appear dimmer

star colours

hot - blue and white

cool - red and orange

element spectra

When light is analyzed, the elements making up the star can be determined by the dark bars/bands created by the elements in the starlight

neutron star

a crushed remnant left over when a huge star explodes

made entirely of neutrons

can pack 2 times as much mass as the sun in a sphere only 10km in diameter

produce pulses of radio radiation called pulsars

nova

star that suddenly and temporarily increases its brightness by 1000x

can go nova more than once and stars are relatively low mass

sun

center of our solar system

average mass, brightness, and size

can go nova or expand into a red giant or shrink to a dwarf star

not enough mass to go supernova

red giant

massive, distended, bright and relatively cool star 100-1000x the size of our sun

if placed where our sun is, would extend out past mars

can go supernova to form neutron stars or black holes if big enough

supernova

a big explosion that marks the end of a very large star

very bright light

white dwarf

collapsed remnant of a low mass star that has used up its fuel for nuclear fusion

shines only by radiating away its stored heat

a dwarf star might have the same mass our sun but only about the size of the earth

3 requirements to be a planet

needs to be in orbit around the sun

it needs to have enough gravity to pull itself into a spherical shape

it needs to have cleared the neighborhood of its orbit - needs to be the dominant figure in its orbit

moon

rotation on its axis is same rate as its revolution around earth

orbit is not on the same plane as the earth

takes 27 1/3 days to orbit the earth once

full moon happens once every 29 days

gravity 1/6 of earth

8 phases of moon

new moon, waxing crescent, first quarter, waxing gibbours, full moon, waning gibbous, third quarter, waning crescent

what are most planets named after

greek or roman gods/goddesses

earth facts

diameter - 12 756 km

distance from sun - 1 AU

N makes up most of atmosphere

mercury

thin atmosphere

88 days in a year

rotation period - 59 days

thin atmosphere - difficult to breathe

very hot or very cold

large core of iron

venus

covered in blanket of yellowish clouds

clouds reflect sunlight, making venus very bright

atmosphere is poisonus and thick atmosphere traps heat - mostly CO2 but N and sulfuric acid are also found

rotates east to west

mars

red planet

has polar caps and surface features like valleys, canyons, volcanoes, and craters

thin atmosphere - made of CO2 with small parts of N, O, Ar, and water vapour

temps are low

2 moons

jupiter

16 moons

largest planet - all other planets could fit inside

made of thick gases - H and He

big red spot - storm/hurricane that is 300 yrs old

stripes - made of different gases

lighter stripes are made from ice crystals of ammonia

saturn

18 moons

7-1000 rings

at poles, the wind of saturn blows in one direction - east

mostly gas - atmosphere is H and He

uranus

15 moons

11 rings

4x size of earth

atmosphere with H and He

bluish green colour - methane gas

first planet to be discovered through telescope

sideways

neptune

8 moons

4 rings

very windy - 1120 km/h

methane, H, and He in atmosphere

methane makes it blue