Download Space History - Net Start Class

Space History
• Ptolemy – 140 A.D. believed in
geocentric system (planet revolve
around Earth)
• Planets
and sun revolve (move)
geo = Earth
around
Earth
centric = Center
• Planets revolve in smaller circles
on a bigger circle at different rates
and some have backward
movements
Space History
• Copernicus – Early 1500’s
believed in heliocentric system
• helio
Sun is= the
Sun center and planets
revolve around
centric = Center
• 6 planets: Mercury, Venus,
Earth, Mars, Jupiter, and
Saturn
Space History
• Galileo – 1500’s -1600’s believed in
heliocentric system
• 1st to use telescope to view objects in sky
• 1st to see 4 moons revolving around
Jupiter
• Provided evidence that everything does
not revolve around Earth - Venus goes
through phases
• Supported Copernicus’ theory – circular
orbit
Space History
• Tycho Brache – late 1500’s observed
planet positions of orbit for 20 years
• Designed, built, and calibrated
astronomy tools.
• Johannes Kepler - 1600’s discovered
via Tycho’s observations that planets
move in elliptical orbits.
Ellipse – An elongated circle, or oval shape
Space History
• Issac Newton – explained why the
planets stay in orbit (inertia and
gravity).
• An object in motion stays in motion
unless acted
up on
by an outside
force –
Inertia
= The
tendency
of
a
Newton’s 1st Law of Motion (The Law
moving
object
to
continue
moving
of Inertia)
or
an
object
not
moving
to
Gravity = The force that pulls
remain
stationary
objects toward each other
Gravity and Inertia
• Inertia & Mass
– Mass is the amount of matter in an
object
– The more MASS an object has, the more
INERTIA the object has.
– Bigger objects are harder to start & stop
• Gravity
– Depends on the masses of the objects
and the distance between them
Time line of Events
• Ancient Greeks – 5
•
•
•
•
wandering star)
points of light (planets =
Ptolemy (140 A.D.) – geocentric system
Copernicus (1514 - 43) – heliocentric system
Brahe (1572-1598) – observed orbit of planets
Galileo (1583-1633) – Provided evidence to support
a heliocentric system (4 moons)
• Kepler (1596-1619) – planets
orbit
move in elliptical
• Newton (1664-) - explained force
planets
and motion of
Systems
Solar system = A large planetary
•system
Then – consisting
6 planets of smaller
•planetary
Now – 8 planets
systems and objects.
• Moon(s) revolve around some
planets.
• Each planet and its moon(s) = small
system
• Combinations of small systems =
large systems
Rotation
vs.
Revolution
• Spinning on an axis
• Causes night and
day
• Moving around
another object
• Causes seasons
• About 24 hours = 1
turn
• Takes about 1 yr for
Earth to revolve
around the sun
The Sun
• A star composed of H & He
• Obtains energy via nuclear fusion
The Sun
http://videos.howstuffworks.com/hsw/6033-our-solar-system-the-structure-of-the-sun-video.htm
• Core
Nuclear fusion = combining of 2
• Photosphere
atomic nuclei to produce a single
•
Chromosphere
larger nucleus releasing energy.
• Corona
The Sun
• Core – The central part of the
sun, where nuclear fusion occurs
Layer of the Sun
• Photosphere – Inner layer –
which makes light
winds = A– stream
of
• Solar
Chromosphere
Middle
layer
photo
=
Light
electrically
charged
particles
– Visible during
total solar
eclipse chromo
reddish= Color
produced
by the sun’s corona. –
• causes
Corona auroras
- Outer layer forming a
halo (crown) – visible only during
total solar eclipse or special
telescope
Features on the Sun
• The sun rotates on its axis
every 30 days
• Sunspots – vary in size
– appear darker than rest of the
photosphere b/c gives off less
light and is cooler
Sunspots
dark,
cooler
– Occur =
in A
small
groups
or region
pairs on
the surface of the sun.
Features on the Sun
• Prominences - Reddish loop of
gas protruding from the sun’s
surface
– links parts of sunspot regions.
– About 10,000 degrees Celsius
Features on the Sun
• Solar flares – Explosion of H gas
from the sun’s surface
– occurs when loops in sunspot regions
suddenly connect.
– increase the solar wind from the
corona
– Cause magnetic storms  auroras in
Earth's night sky & disrupts radio
transmission