SES4U - Exploration Flashcards
How big are Dwarf Planet/Satellites Approximately
1 Megametre
Dwarf Planet
“almost planets” 2/3
Satellite
Orbits around Planets
Planet
Big, Bad Ball goes around the sun 3/3
What makes a planet orbit fast or slow
Moves faster around the sun when closer,
What shape does the comet make when orbiting the sun
Elispses
What shape does the comet make when orbiting the sun
Ellipses (Speeds up when closer to the sun)
Celestial Objects
Anything out in space, they can be either solids/blob or clusters/collection
What do we measure the distance between planets
AU - Astronomical Unit, 150 million Km
The distance between in the galaxy measured in ?
Light years = 9.38 x 10^12km or 60,000 AU
Lightyear?
Distance that light travels in one year
Timekeeping and astronomy
Astrology is filled with cycles
stars/sun set - days
moon phases - months
earth rotates around sun - years
Navigation and astronomy
NorthStar use for navigation
Astrology
pseudoscience
connecting/central by the heaven “Attempting to explain to observation”
Eratosthene c.250BC
Pole and and a well
sun over head at we;;
angle at pole with right angle
find angle and use distance to solve
Navigation and astronomy
Northstar use for navigation
Ptolemy c.200CE
Geocentric model
in the western world - Ptolemaic model
This explained what was happening in the sky, and felt good too makes us feel important
Retrograde
orbital or rotational motion of an object in the direction opposite the rotation of its primary, (backward epicycles)
Heliocentric Model
Sun centered model
Motion of the stars - Arguments for geo and helio
Geo - Stars are fixed to a heavenly sphere that rotates around us
Helio - Earth rotates around the sun
Star Parallax - Arguments for geo and helio
Geo -No obeserved stellar parallax(star shifting), so we must always be positioned in the same spot
Helio - They do shift; They’re just too far to see it visually
Changing appearance of planets - Arguments for geo and helio
Geo - Planets experience retorgrade motion and get brighter/dimmer, so they must follow their own epicycles
Helio - also explain retrograde motion but much simpler
Phases of Venus - Arguments for geo and helio
Geo - huh!
Helio - we see venus/sun at diff angle
Galilean Satellites
Geo - whaaaa?
Helio - Things can orbit anything else
Sunspots
Geo - uhhhhh
Helio - Sun rotates why not earth
Copernicus c.1500
Proposed the a heliocentric model
where earth rotates but planets still follow epicycles
this explain equinoxes and was much simpler then Ptolemy model
But it meant the earth move, therefore church no like
Tycho & Keplers (late 1500’s)
Brage recorded the measurements, kepler formulated his three laws of planetary motion based on them
Galileo (early 1600’s)
First to use a telescope for astronomy
found 4 satellites orbiting Jupiter
not explained with geo but explained with Helilo
Kepler’s first Law
Planets orbit the sun in ellipses; sun on foci
Ellipses are ovals
You can calculate how stretched a circle is
e = c/a
c = the distance between the two foci
a = when the radius is the largest ( semi major axis)
planets have a e of 0 - 0.2
circle has e of = 0
comets have a e of 0.2 - 1
if e > then 1 its a parabola
Eccentricity
how stretched a circle is
Kepler’s Second Law
Planets sweep out equal areas in equal amounts of time
triangle?
Kepler’s Third Law
The square of a planets period is proportional to the cube of its semi major axis
P^2 = ka^3
p in earth years
a in semi major axis
Where is the surface of gas planets
Atmosphree of earth must = gas planet thingie
Angular height?
Altitude
Angular distance
Azimuth
What do we call the poles
celestial poles
Zenith?
Point directly overhead us at current point
nadir
The point directly under
Equatorial grid
As if all objects in space are fixed on a sphere that we’re inside of, like an inside out globe
Longitude of a equatorial grid
Right ascension, Hours, mins, seconds
Latitude of a equatorial grid
Declination, Deg, min, secs
Circumpolar Stars
Stars that never set
What declination is stars circumpolar in the north, south, and center of the earth
45> - north
non - center
? - south
Ecliptic
A path that follows all the constellations, and planets; the plane of Earth’s orbit around the Sun. It extends beyond that to include the seven other planets
Asterisms
A familiar grouping of stars
Why are days in junes loner
Because the earth is tilted towards the sun and the sun shines more directly onto our part of the earth vice versa for december, shorter days due to the shallower angle
Solstices for winter and summer
Dec 21 and June 21
Solstices for winter and summer
Dec 21 and June 21
Equinoxes
Vernal equinox - spring march 21
autunnol Equinox - fall sept 23
*equal Day
Sidereal day
How long it takes stars to be in view
23 hrs, 56mins and 4 sec
solar day
24hrs and sun backed
Light
The transfer of energy through a wave of ever changing electric and magnetic fields
Colour of light we see?
Determined we see with wave length and frequency
Incandenscence
Objects/material glow when they get got this produces a continuous spectrum
they get brighter and bluer when heated up
Types of spectra
Continuous - Shows all diff colours
Emission line spectrum when atoms are energized and releases light (very specfic colours)
Absorption line spectrum select colours are absorbed because of different atoms
Telescopes
giant eyes that collect light
Focus light and makes images look brighter
two types of telescopes
refractor - lenses
refracts the light to a small point
reflectors - curved mirrors
Larger diameter telescopes?
Collect and focus more light meanig they produce brighter images, also a higher resolution
CCD
Digital sensors that are used to collect observations, cam ne used filters to capture images, or in combination with spectroscopes to record an object’s spectrum
ISIM
Houses akk if webbs camera and science instruments
