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Astronomy = the study of the universe
Astro = star
Centr = center
Geo = earth
Retro = back
Pre = before
Peri = around
Mar = ocean
Terre = ground
Sol = sun
Chrom = color
pro = first
Astronomical History!
•
Geocentric Model = moon, sun and planets orbit Earth.
Astronomical History!
•
Heliocentric Model = Earth and other planets orbit sun.
Astronomical History!
•
Ptolemaic System = Planets orbit Earth, but seemed to
exhibit retrograde motion.
Copernicus:
Earth is a
planet that
orbits the sun.
Astronomical History!
Brahe: Yes, but
my observations
are much more
precise.
Kepler: No, my
3 laws of
planetary
motion prove
that Brahe is
wrong.
Newton: The
planets are held
into a circle by the
gravity of the sun.
Galileo: Well, here
is how the planets
and their satellites
move.
Earth – Moon - Sun
Rotation = spinning
Revolution = going around another object
Earth Rotating
http://svs.gsfc.nasa.gov/vis/a000000/a001300/a001374/index.html
Perihelion
CLOSEST
Aphelion
FARTHEST
SEASONS
Plane of the Ecliptic = reference plane that runs from pole to pole.
Plane is tilted about 23.5o.
Seasons are result of the tilt.
More Earth Movement
Precession = very slow wobbling
http://earthobservatory.nasa.gov/Features/Mil
ankovitch/Images/milankovitch_precess_high.
mov
Earth - Moon
Perigee = moon is closest to earth
Apogee = moon is farthest from earth
Phases of the Moon
http://videos.howstuffworks.com/hsw/10001-the-moon-phases-video.htm
ECLIPSE
Solar eclipse = moon is between earth and sun (like the
background here!) and casts a shadow on Earth.
Lunar eclipse = Earth moves between sun and moon and casts
shadow on moon.
Man on the Moon
http://news.sky.com/skynews/Home/WorldNews/Nasa-Releases-Footage-Of-MoonLanding-When-Astronaut-Neil-Armstong-TookFirst-Steps-On-July-201969/Article/200907315338603
Earth’s Moon
• The Only Natural Satellite
• 1/4th diameter of Earth
• Apollo moon mission 1969-1972
• Gravity 1/6th that of Earth
• 150 lb person = 25 lbs
Craters
• round depressions
• produced by impacts
Impact by meteor.
Compresses surface
material.
Rebound splash of ejecta.
Uplift of deep rock in
center.
Major Topographic features of the Moon:
Highlands = light colored areas (almost as high as Mt. Everest!)
Mare (Maria, pl.) = dark smooth areas (ancient beds of lava)
Rilles are valleys or trenches.
Regolith = soil-like layer
Lunar History
When solar system was forming, a body the size of Mars impacted
Earth and the debris shot into space. One piece was our Moon.
How the Moon Formed
http://videos.howstuffworks.com/hsw/9998the-moon-formation-video.htm
Formation of the Solar System
Nebular Theory = sun and planets formed from a rotating disk
of dust and gases.
Planetesimals = small, irregular-shaped bodies that collided
and clumped together to form the planets.
The Solar System
Terrestrial Planet = small and rocky (inner planets)
Jovian Planet = large gaseous (outer planets)
http://player.discoveryeducation.com/index.cfm?guidAssetId=21B610C4-B1BB-40E08760-825A41B19E12&blnFromSearch=1&productcode=US
Asteroids = small, rocky bodies floating in space
(Largest, Ceres, is about 1000 km in diameter!)
Comets = pieces of rocky and metallic materials held together
by frozen gases like water, ammonia, methane, etc.
(Some take hundreds of thousands of years to make
one orbit.)
Small Pieces (w/Quiz)
http://player.discoveryeducation.com/index.cf
m?guidAssetId=BD722E4D-32D2-4342-B475F031BFDC4EEC&blnFromSearch=1&productco
de=US
Coma = the glowing head of a comet produced when
the sun begins vaporizing the comet’s frozen gases.
Tail = stream of glowing vaporizing gases
Halley’s Comet
76-yr-orbit
Kuiper Belt = disc-shaped region beyond Neptune
where short-orbital comets originate.
Oort Cloud =
area spreading in
all directions
from the sun
where longorbital comets
originate.
Meteoroid
METEORS!
• small, solid particle
• travels through space
• origination
• interplanetary debris
• asteroid belt material
• remains of comets
Meteor
• meteoroid that enters
Earth’s atmosphere
• Meteor Shower = a
group of meteors traveling
in the same direction
Meteor in Peru 2007
http://news.bbc.co.uk/player/nol/newsid_7000000/newsid_7002300/7002376.stm?bw=bb&mp=wm&asb=1&news=1&ms3=54&ms_javascript=
true&bbcws=2
The SUN
Photosphere = visible
surface (90% hydrogen)
Chromosphere = thin
layer of hot gases (can
see during solar eclipse)
Corona = weak
outermost layer
(extends 1 million km)
Solar wind = streams
of protons and
electrons
Corona
Convective Zone
Radiative Zone
Core
Photosphere
Earth
Chromosphere
Activity of the Sun:
Sunspots = appear dark because they are cooler than the rest of
the sun.
http://www.windows.ucar.edu/tour/link=/sun/atmosphere/sun_rot
ate_anim_jan2005.html&edu=high
Prominences = large cloudlike structures consisting of
chromospheric gases.
Solar Flares
• explosive events
• last about an hour
• sudden brightening
above a sunspot
cluster
• release enormous
amounts of energy
• ejects atomic particles
• produce auroras
(northern lights)
http://images.google.com/imgres?imgurl=http://veimages.g
sfc.nasa.gov/10194/a001168_pre.jpg&imgrefurl=http://visib
leearth.nasa.gov/view_rec.php%3Fid%3D10194&usg=__0rK
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http://images.google.com/imgres?imgurl=http://earthobser
vatory.nasa.gov/images/imagerecords/3000/3912/flare_soh
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It’s how far??!!
1 Light Year = how far light travels in one year.
Light travels at 299,792,458 m/s so in one
year light goes 5.88 trillion (5.88 × 1012)
miles.
1 A.U. (Astronomical Unit) is the distance from
the Earth to the Sun which is 150 million km
(93 million miles).
Earth’s diameter = 7,926 miles
ANTARES IS THE 15TH BRIGHTEST STAR IN
THE SKY. IT IS MORE THAN 1000 LIGHT
YEARS AWAY.
THIS IS A HUBBLE TELESCOPE ULTRA DEEP
FIELD INFRARED VIEW OF COUNTLESS
'ENTIRE' GALAXIES BILLIONS OF LIGHTYEARS AWAY.
BELOW IS A CLOSE UP OF ONE OF THE
DARKEST REGIONS OF THE PHOTO ABOVE.
Sun’s diameter = 870,000 miles
Sirius is the brightest star in
the night-time sky. It is located
in the constellation Canis
Major. It is 8.5 light years
away.
Pollux is 33.7 light years away.
Arcturus is 36.7 light years
away.
ANTARES IS THE 15TH
BRIGHTEST STAR IN THE SKY.
IT IS MORE THAN 1000 LIGHT
YEARS AWAY.
How to Build a Star
1. Locate a nebula (cloud of dust and gases).
How to Build a Star
2. Contract your nebula.
How to Build a Star
3. Squeeze your nebula more using gravity.
How to Build a Star
4. Convert the gravitational energy into heat energy.
How to Build a Star
5. Conversion gives you a protostar.
How to Build a Star
6. Continue to squeeze until the core reaches 10 million K of pressure.
Congratulations…It’s a Star!
How to Raise a Star
1. Provide support and guidance while your young star struggles with
internal gas pressures and forces of gravity.
How to Raise a Star
2. Have your star identified by a star doctor to determine its color.
Blue stars burn fast and die quickly in about 3 million years.
Yellow stars brun slowly and live about 10 billion years.
How to Raise a Star
3. Provide senior care as your star reaches the red-giant stage and its
core is consumed.
How to Raise a Star
4. Apply gravity to offset the loss of fuel.
The Death of a Star
1. Prepare for the eventual collapse of your star by gravity.
The Death of a Star
2. If your star was a low mass star, care for it as it collapses into a
white dwarf.
The Death of a Star
3. If your star was a medium mass star, care for it as it bloats into a
planetary nebula.
The Death of a Star
4. If your star was a massive star, run away! A supernova is coming!
The Death of a Star
5. When your star goes supernova, prepare for a black hole.
Black holes are made when pieces of stars 3x bigger than our sun
collapse making smaller objects with immense gravitational
pulls. The gravity is so strong that not even light can escape.
Home Sweet Home
Galaxy = group of
dust, stars, and gases
held together by
gravity.
Circinus Galaxy
Cartwheel Galaxy
Sombrero Galaxy
Andromeda Galaxy
Methusala Galaxy
Home Sweet Home
Milky Way Galaxy
Google Earth to space
ASSIGNMENT:
PH CH 22, 23, 24, 25