Physical Science                     Mr. Seegers               

The Solar System

Astronomy
-is the scientific study of the universe beyond Earth’s atmosphere.

The Universe
-is everything, all energy, matter and space

Our existence is totally based on the sun
- all species evolved based on solar energy
- sun influences weather

The Solar System
- the sun is the center of our solar system (dominant mass)
-9 rotating planets with 60 satellites (moons)
- 1000’s of asteroids, comets, meteoroids and dust

Distances in the solar system is measured in astronomical units (AU) = 1.5 x 108
- average distance earth and the sun

Terrestrial Planets
-inner planets
- Mercury, Venus, Earth, Mars
- smaller in mass
- composed of rocky material and iron cores
- solid surfaces and weak magnetic fields

Jovian planets
-outer planets
- Jupiter, Saturn, Uranus, Neptune

Pluto
- controversy over classification as planet or asteroid

Planets
- have elliptical orbits

Rotation
- spinning on internal axis
-24 hours (Earth’s)

Revolution
- is the movement of one mass around another
-earth revolves around the sun
- our moon revolves around the earth

The terrestrial planets

Earth
- is unique, has large amounts of surface water
-oxygen containing atmosphere (21%)
- temperate climate
- living organisms
- 12,900 km diameter
- surface temp 20 degrees C
- Comp of Atmosphere 78% N, 21% O, 1% Ar

Mercury
- closest planet to the sun
- shortest revolution (88 days)
- fastest moving of all planets
- surface is similar to our moon
- surface temp 350 degrees C

Venus
- closest planetary neighbor to earth
- 3rd brightest object in sky (Sun and Earth’s Moon are brighter)
- has similar gravity, mass, and size to earth
- atmosphere comp 96% carbon dioxide, 4% N
- surface temp 480 degrees C Why?

- surface cannot be viewed from earth due to large clouds
- clouds are mostly Sulfuric Acid
- high atmospheric pressure holds dust and rain giving Venus it’s yellow color
- terrain is high cliffs, mountain chains and volcanic planes (80%)

Mars
- surface temp of 20 degree C
- rotation is 24.5 hours
- about 23 earth months, 687 days to revolve once around sun
-two small moons Phobos (32km diameter) and Deimos (1/2 size of phobos)
- moons are irregular shaped and heavily cratered
- mars has 2 polar caps (made of dry ice)
-12 extinct volcanoes
Olympus Mons,
-largest volcano in our solar system 24km high and 600 km wide at base

Vales Marineris
- huge canyon 4000 km long and 6 km deep ( = to width of U.S.)
- Mars has large ancient channels that were formed by some liquid
- life may have existed on Mars, some evidence has been discovered


Planet Profile
Jupiter

Mass (kg) 1.90 x 10^27
Diameter (km) 142,800
Mean density (kg/m^3) 1314

Average distance from Sun (AU) 5.203
Rotation period (length of day in Earth hours) 9.8
Revolution period (length of year in Earth years) 11.86
Mean surface temperature (K) 120 (cloud tops)
Atmospheric components 90% hydrogen,
10% helium,
.07% methane
Rings Faint ring (rock fragments)

Jupiter's Moons

four large moons Io, Europa, Ganymede and Callisto

Europa - covered with ice, may have vast oceans under ice. Could have possible life.

Jupiter was first visited by Pioneer 10 in 1973 and later by Pioneer 11,
Voyager 1, Voyager 2 and Ulysses. The spacecraft Galileo is currently in orbit
around Jupiter and will be sending back data for at least the next two years.

Considered to be a planet made of gases and dust with a small rocky core.

Massive global storms occur frequently (estimated 400mhr wind speed )

Jupiter vibrant colors come from chemical reactions, dust and storms.
Saturn
Planet Profile
Mass (kg) 5.69 x 10^26
Diameter (km) 120660
Mean density (kg/m^3) 690
Escape velocity (m/sec) 35600

Average distance from Sun (AU) 9.539
Rotation period (length of day in Earth hours) 10.2
Revolution period (length of year in Earth years) 29.46
Mean temperature (K) 88 K (1 bar level)

Visual geometric albedo (reflectivity) 0.46
Atmospheric components 97% hydrogen,
3% helium,
.05% methane
Saturn's interior is similar to Jupiter's consisting of a rocky core,
traces of various ices are also present.

Saturn's interior is hot (12000 K at the core) and Saturn radiates
more energy into space than it receives from the Sun.

Rings
-270,000 km in diameter, but only a few hundred meters thick.

Particles are centimeters to decameters in size and are ice (some
may be covered with ice); there are traces of carbon minerals.

There are four main ring groups and three more faint, narrow ring groups
separated by gaps called divisions.

18 moons (major moons)
Uranus
Planet Profile
Mass (kg) 8.68 x 10^25
Diameter (km) 51118
Mean density (kg/m^3) 1290
Average distance from Sun (AU) 19.18
Rotation period (length of day in Earth hours) 17.9
Revolution period (length of year in Earth years) 84
Mean temperature (K) 59
Visual geometric albedo (reflectivity) 0.56
Atmospheric components 83% hydrogen,
15% helium,
2% methane

composed primarily of rock and various ices

Rings
Uranus has a system of narrow, faint rings.
Ring particles are dark, and could consist of rocky or carbonaceous material.

The greenish color of Uranus' atmosphere is due to methane and high-altitude photochemical smog.

has been visited by only one spacecraft, Voyager 2 on Jan 24 1986

composed primarily of rock and various ices

has 15 named moons plus 5 recently discovered ones
has the most known moons of any of the planets.


Neptune
Bright Blue Color (caused by Methane)

Climate
-strong winds up to 400 mph

Neptune has been visited by only one spacecraft, Voyager 2 on Aug 25 1989.
Almost everything we know about Neptune comes from this encounter

Planet Profile
Mass (kg) 1.02 x 10^26
Diameter (km) 49528
Mean density (kg/m^3) 1640
Average distance from Sun (AU) 30.06
Rotation period (length of day in Earth hours) 19.1
Revolution period (length of year in Earth years) 164.8
Mean temperature (K) 48

Visual geometric albedo (reflectivity) 0.51
Atmospheric components 74% hydrogen,
25% helium,
1% methane
Rings
-narrow and contain concentrations of particles

Neptune has 8 known moons

Little is known about this planet



Pluto
Planet Profile
Mass (kg) 1.29 x 10^22
Diameter (km) 2300
Mean density (kg/m^3) 2030
Escape velocity (m/sec) 1100

Average distance from Sun (AU) 39.53
Rotation period (length of day in Earth days) 6.39
Revolution period (length of year in Earth years) 247.7

Mean temperature (K) 37

Visual geometric albedo (reflectivity) about 0.5

Atmospheric components perhaps methane and nitrogen
Surface materials perhaps methane ice

Pluto is the only planet that has not been visited by a spacecraft.
Even the Hubble Space Telescope can resolve only the largest features on its surface

Space Travel

Apollo Human Missions

1 cancelled first planned human mission; crew killed in 1/27/67 fire during rehearsal
7 first manned Apollo flight; practiced rendezvous in Earth orbit

8 first human flight to orbit the moon

9 tested Lunar Module in Earth orbit

10 tested Lunar Module in lunar orbit

11 first lunar landing (Sea of Tranquility)

12 second lunar landing (Ocean of Storms)

13 mission aborted

14 third lunar landing (Fra Mauro)

15 fourth lunar landing (Hadley-Appenine region);
first use of "Rover" vehicle on moon

16 fifth lunar landing (Descartes Highlands)

17 sixth lunar landing (Taurus-Littrow); final Apollo mission

Apollo 11

The Astronauts

Neil A. Armstrong--Commander
Michael Collins--Command Module Pilot
Edwin E. Aldrin Jr.--Lunar Module Pilot

The Mission Objective

Perform Human lunar landing and return mission safely

Launch

Apollo 11 was launched on July 16, 1969 at 9:32am EDT at Kennedy Space Center,
Florida, from Launch Complex 39-A. The Launch Complexes 39-A and 39-B were originally
built for the Apollo program, and were later altered to support Space Shuttle missions.


Duration

The Apollo 11 mission lasted 8 Days, 3 hours, 18 minutes, and 35 seconds.

Landing

The Apollo 11 spacecraft splashed down on Earth on July 24, 1969 at 12:50 p.m. EDT.

Mission Accomplishments

The Apollo 11 lunar excursion module landed on the moon on July 20, 1969 at 4:17 PM EDT,
in the area of the moon known as the Sea of Tranquility.
It was the first human lunar landing mission.

The United States flag was set upon the moon

The Astronauts stayed on the moon for 21.6 hours. This mission
was the first to return samples from another planetary body.
These first samples were basalts, dark-colored igneous rocks,
which were about 3.7 billion years old.


Moon

-384,000 km (average distance from earth)
-5th largest moon is our solar system
- 1/4 size of earth
-the surface gravity is 1/6 that of earth
-small iron rich core

Craters
- more than 40,000 craters are visible with a earth based telescope
- some are hundreds of kilometers in diameter
-caused by impacts with meteorites
-mountain chains with 6000m high peeks

Composition
-no rock samples returned were older than 4.4 billion years old or
younger than 3.1 billion years old
-has no atmosphere or water on surface (erosion does not occur)
too little gravity, to retain atmosphere

-most meteorite craters on earth have been eroded away
-past volcanic history which caused the plains to form
-dust layer several meters thick from bombardments from meteorites