astro (11.1- 11.3)🪐 Flashcards
what is the sun core temp and surface temp
huge glowing ball of gas, surface temp of 6000C and core temp of 15 million C
How is the sun’s energy released
what is radiated
Nuclear reactions in the core of the sun
radiates in the Infrared, visible and ultraviolet regions of the em spectrum
what are the gases the sun is made up of
helium and hydrogen
what is the path the earth takes to move around the sun called
an orbit
what is the reason some regions get varying hours of daylight throughout the year
the earth’s axis is tilted by 23.5 degrees
zone A and zone B receive equal amounts of energy per second. why is zone A colder than B
zone A has a larger surface area so the energy is more spread out
how many days does the moon’s orbit take
27.3 days
why do humans see only one side/face of the moon
because the moon takes 27.3 days to turn on its own axis
orbital speed formula
2piR/T
Circumference/time
planets from the sun to outwards
mercury
venus
earth
mars
asteroids
jupiter
saturn
uranus
neptune
pluto
My Very Easy trick: Just Say the Nine Planets
however this acronym misses out on mars and uranus
mars after earth
uranus after saturn
essentially, the two words with t (trick, the) are other planets - mars and uranus
what happens to the planet’s orbit as it goes further away from the sun
planet moves slower in its orbit as distance increases from sun
what happens to the surface temperature of the planet as it goes away from the sun
surface temperature decreases
how long does the earth take to complete one revolution on its axis
24 hrs
what does the solar system contain
1 star
8 planets
dwarf planets and asteroids that revolve around the sun
moons that orbit planets
smaller bodies: comets, natural satellites
which bodies have elliptical orbits
planets (mercury and mars), minor planets and comets
when is the sun at the centre of the orbit
when the orbit is approximately circular
what do the 4 planets closer to the sun have in common
they are all rocky and small
what do the 4 planets farther from the sun have in common
they are gaseous and large
how are orbits formed
due to the suns gravitational pull on the planets/ due to gravity
what does the strength of a planets gravitational field depend on
the planets mass
when does the strength of a planet’s gravitational field decrease
as you get further away from it
why does an object in an elliptical orbit travel faster when closer to the sun
gpe converts to ke
gravitational field strength increases as you go closer to the sun
what contains nearly 99.9% mass of the solar system
the sun
What are the inner planets
aka
Mercury
Venus
Earth
Mars
aka terrestrial planets
What are the outer planets
aka
Jupiter
Saturn
Uranus
Neptune
aka gas giants
Characteristics of mercury
Closet to sun
Cratered surface and no atmosphere
Characteristics of venus
Brightest object in the night sky (except moon)
Alm same size as earth
Planet is covered by clouds of sulfuric acid
Atmosphere is 97% carbon dioxide - lots of greenhouse effect. Temps can reach 500
Characteristics of earth
Only planet in solar system that can support life
Char of mars
Thin atmosphere mainly of co2
dusty surface
Has volcanoes but aren’t active
Scientists believed water once flowed on mars because of the shapes of the valleys.
Describe orbits of asteriods
Most have orbits between mars and jupiter
Some have eliptical orbits that cross other planets’ orbits. Eg: 65 mil years a 10km wide struck earth (dino extinction)
Char of jupiter
More massive than all other planet put together
Atmosphere is 90% hydrogen
Great red spot - huge storm that has been going on for centuries
Moon Io - only other place other than earth where there are active volcanoes
Char of saturn
Sorrounded by thin rings - made of millions of ice pieces.
Each piece is a ‘moonlet’ in its own orbit around saturn
Char of uranus
Axis of rotation tilted more than 90 deg
also has rings but they are fainter than saturn’s
Char of neptune
Outermost planet - has very faint rings
Char of pluto
Recently considered as a dwarf planet because of its small size.
Describe a comet
Highly eliptical orbits
Head of a comet- icy lump
When it receives heat from the sun - particles of dust and gas stream off into space. Form a long tail thats millions of kms long
Tail is visible cuz it reflects sunlight
