Astronomy Notes23.1-The Solar System

The Planets: An Overview The 8 planets in our solar system can be separated into _________________different categories

1. _____________________________________________________

2. _____________________________________________________

1. Terrestrial planets _________________________________________________ Includes Mercury, Venus, Earth, Mars

Relatively ___________________________________________________________________________

What does terrestrial translate to?

___________________________________________________

2. Jovian planets _______________________________________________________

Includes Jupiter, Saturn, Uranus, Neptune

________________________________________________________________

What does jovian translate to? “Jupiter-like”

The Planets: An overview

_____________________________ is the most obvious difference between the terrestrial and Jovian planets The Jovian planets are giants compared to the terrestrial planets

_______________________________________________________________________________________________________________

_______________________________________________________________________________________________________________ are other ways in which the two groups of planets differ

Jovian planets are ____________________________________________ while terrestrial planets are more dense

Jovian planets are _______________________________________________

Jovian planets rotate around the sun much ________________________________ than the terrestrial planets

The Planets: An Overview The Interiors of the Planets

All planets (and Pluto) are made up of ___________________________________________________________

The Atmospheres of the Planets Jovian planets have thick atmospheres of hydrogen, helium, methane and ammonia

Due to the large amount of _____________________________________________on these planets

Terrestrial planets have _________________________________________________________________

Due to the small amount of gravity on these planets

Formation of the Solar System Nebular Theory

A ________________________________is a cloud of gas and dust in space

According to the nebular theory, the sun and planets formed from a rotating disk of

___________________________________________________ As the disk rotated faster the

______________formed in the middle

_________________________________________________ Planets grew as solid bits of matter began to

collide and clump together through a process known as

________________________________________ The colliding matter formed small irregularly shaped bodies called planetesimals As the collisions continued these planetesimals grew into planets

23.2- The Terrestrial Planets Mercury: The Innermost Planet

The innermost and _______________________________________________________planet in our solar system; just slightly larger than Earth’s moon

Surface Features Has ___________________________________________________________________

Surface Temperatures Has the ____________________________________________________________ of

any of the planets

It can get as cold as -173°C at night and as hot as 427°C during the day

Venus: The Veiled Planet Called ___________________________________________________

Venus is similar to Earth in ___________________________________________

______________________________________ in the solar system.

Surface Features Covered in thick clouds that _________________________________________________________ from hitting the

planet About 80% of Venus’s surface is covered in _______________________________________________

Surface Temperatures Atmosphere is 97% _____________________________________________, making it ______________________

Mars: The Red Planet The Martian Atmosphere

Contains carbon dioxide with a small amount of water vapor

____________________________________________________________________ on Mars cause it to look different colors at times through a telescope from Earth

Surface Features Consists of __________________________________________________________________________________________

These features are billions of years old

Water on Mars Some areas of Mars exhibit _______________________________________________

___________________________ similar to those created by ____________________

on Earth

Images from the Mars Global Surveyor indicate that ___________________________________________

_______________________________________________________________________________________________________

23.3- The Jovian Planets (and Pluto) Jupiter: Giant Among Planets

Jupiter has a mass that is ____________________________________________________ than the mass of all the

other planets and moons in our solar system ______________________________________________

Structure of Jupiter Contains several gases such as hydrogen,

helium, methane, ammonia, and water

Incredibly ____________________________________

_________________________________________________

The _______________________________________ is a large storm, similar to that of a hurricane

Jupiter’s Moons Jupiter has ____________________ moons, which makes it resemble a mini solar system

Jupiter’s Rings One of the most unexpected discoveries made by Voyager 1

Thought to be formed of fragments from ________________________________________________________

_______________________________________________________________________________________________________

Saturn: The Elegant Planet The most prominent feature of Saturn is _________________________________ Features of Saturn

Saturn’s atmosphere is very active, with winds roaring up to _________________________________

_______________________________________________________________________________________________________

Saturn’s Rings Was once that that this was the only planet to have rings The inner rings are more densely packed with particles

while the outer rings are less densely packed with particles

Saturn’s Moons Contains ________________ moons The largest moon is Titan, which

is larger than __________________________________

Uranus: The Sideways Planet Uranus is unique in that it rotates on it’s side

Neptune: The Windy Planet Winds exceeding 1000 km/hr make it one of the

__________________________places in the solar system

Pluto: Dwarf Planet

Until _______________________ Pluto was considered to be a planet

Pluto is _______________ considered to be a planet because its

gravity is ____________________________________________________________________________________________________

As a result, the term ___________________________________________ was created.

Dwarf Planet : _______________________________________________

_________________________________________________________________

_________________________________________________________________

_________________________________________________________________

23.4-Minor Members of the Solar System Asteroids

Definition: __________________________________________________________________________________________________

Most asteroids lie in the asteroid belt between _________________________________________________________

Comets Definition: Pieces of ________________________________________________________________________________________

_______________________________________________________________________________________________________________ Comets also orbit the sun

Meteoroids Meteoroid : a small, ________________________________________

______________________________________________________________

____________________________________: the phenomenon observed when a meteroid enters Earth’s atmosphere and burns up, popularly called a ____________________________________________

Meteorite : any portion of a meteoroid that

__________________________________________________________________

__________________________________________________________________

Meteoroids originate in one of the following ways1. Debris that was not swept up by the gravity of other

planets during the formation of the solar system

2. _______________________________________________________________________________________________________

3. Solid remains of __________________________________________ that once traveled near Earth’s orbit

24.1- The Study of Light How do scientists know all this information about the planets? And how do they know so much about objects that

are further away, such as stars? The majority of the information we know about the universe is obtained from ______________________

_______________________________________________________________________________________________________________

Electromagnetic Radiation _______________________________________________________________________________________________________________

These electromagnetic waves have different ____________________________________________________________

The human eye can only see a certain range of wavelengths,

in what is called the ______________________________________________________

The continuous spectrum is caused by

things like the_________________________________________

Emission spectrum Also known as “bright line spectra” These lines are made by glowing elements

in a star, and can be seen with an instrument called a

____________________________________________ Below is the emission spectra of hydrogen

produced by a star

Absorption Spectrum When a visible spectrum of a star passes through the __________________________________________

____________________________________________________ of the star

The gas in a star __________________________________________ certain wavelengths of light, resulting in the appearance of dark lines

____________________________________________________________ spectra of stars

Also known as “dark line spectra”

Each spectrum is like a _______________________________________________ of a star, telling us what element the star is made up of

The Doppler Effect In astronomy, the doppler effect is used to determine whether _______________________________________

_______________________________________________________________________________________________________________

On Earth, the doppler effect is the change in sound, or pitch of an object, compared to the location of the observer

Red Shift Objects moving away from the observer exhibit a ______________________________________________

wavelength, or a shift towards the_____________________end of the electromagnetic spectrum

Using the doppler effect, scientists have discovered that ______________________________________

_______________________________________________________________________________________________________

What does this mean? All stars and galaxies in the universe are moving _______________________________________

_______________________________________________________________________________________________

24.2- Tools for Studying Space Telescopes

Instrument that aids in the observation of distant objects, such as stars and planets, that give off electromagnetic radiation

Types of Telescopes

1. _________________________________________________________

2. _________________________________________________________

3. _________________________________________________________

4. _________________________________________________________

1. Refracting Telescopes Telescope that uses a lens _________________________________________________________________________

The ________________________________________________ bends all of the light rays onto one spot,

the _________________________________, or central point, so that the eye can see the object clearly

2. Reflecting Telescopes A telescope that ___________________________________________________________________________________ before it

focuses the image Benefits of the reflecting telescope

_____________________________________________________________________

_____________________________________________________________________

Properties of Reflecting and Refracting Telescopes

Both reflecting and refracting telescopes have 3 properties that aid astronomers in their work

1. ____________________________________________________________________________ (can see dim objects)

2. _________________________________________________________________________ (can see images clearly)

3. ___________________________________________________________________________ (can see small objects)

3. Radio Telescopes Detect radio waves emitted by far away

_________________________________________________

A satellite TV setup is really just a simple radio telescope

Advantages of Radio Telescopes Less affected by the weather

_________________________________________________________________________

Can be used during the day

Can “see” through interstellar ___________________________________________________________

4. Space Telescopes

Orbit ____________________________________________ Earth’s atmosphere Advantages:

Above clouds and the Earth’s atmosphere Can be used during the day

Disadvantage: _____________________________________________________; if it breaks there is no way to fix it

______________________________________________________________ Launched in 1990 by the space shuttle “Discovery” Photos are much higher in quality than Earth based reflecting or refracting telescopes

25.1- Properties of Stars Characteristics of Stars

Star Color and Temperature Color is a clue to a star’s temperature

___________________________________

___________________________________

Binary Stars and Stellar Mass

____________________________________________are two stars that revolve, or rotate, around each other

They rotate around each other at their __________________________________________________

Because of this, binary stars are used to find the _______________________________

Distances to stars are so large that units such as kilometers are too hard to use.

Scientists instead measure the distance to a star in________________________________________________ Light Year

The distance light travels in ___________________________________

Stellar Brightness The measure of a star’s brightness is its_____________________________________________________

_____________________________________________

Brightness of a star when _______________________________________________________________ 3 factors control the apparent brightness of a star from Earth

1. How ___________________________________

2. How ___________________________________

3. How ____________________________________

Measuring Distances to Stars Parallax

Slight shift in the ________________________________________ position of a star in the sky

The ____________________________________ the star, the

_______________________________ it appears to move in the night sky

The _____________________________________ the star, the

_______________________________ it appears to move in the night sky

Absolute Magnitude How bright the star ________________________is from a distance of 32.6 light years away

Hertzsprung-Russell Diagram (_____________________________________________)

Shows the relationship between the ______________________________________________________________and

_________________________________________________________of a star

HR Diagram stars

________________________________________________ Star that falls into the main sequence category on the diagram

________________ of stars fall along this part of the diagram

Hottest stars are the _______________________________________(blue)

Coolest stars are the _______________________________________ (red)

Red Giant Large, cool bright star; it is in the ___________________________________________________ of the

HR Diagram

________________________________________________ Bigger and brighter than a red giant

White Dwarf

_________________________________________

25.2-Stellar Evolution Star Birth

Stars are born in _______________________________________________________________________________

Protostar stage A collapsing cloud of gas and dust in the process of ________________________________

________________________________________ When the center of a protostar has reached about_________________________________

nuclear fusion of hydrogen begins and ______________________________________________

As hydrogen atoms fuse together they create helium atoms, which stay

in the _____________________________________of the star.

As a result, the remaining hydrogen fusion moves

___________________________________and away from the center of the star

Main Sequence Stage Different stars _________________________at different rates

Massive stars exist for only a few __________________________________________

Small stars exist for perhaps hundreds of _________________________________

A star spends 90% of its life on the main sequence stage of the HR Diagram

Red Giant Stage Remember, hydrogen fusing has continued to move out and away from the core

The red giant forms when hydrogen fusion_________________________occurs on the

_____________________________________ part of the star (_____________________ the core)

This causes the star to cool (_____________________________________________) and

expand (____________________________________________)

Hence the name Red Giant

Burnout and Death All stars eventually run out of fuel and ____________________________________

Death of _________________________________________ Die as a white dwarf without ever turning into a _____________________________________________

Death of Medium-Mass Stars As the red giant collapses into a white dwarf a

cloud of gas called____________________________________

is formed

Death of Massive Stars A ________________________________________is an exploding massive star

Will produce either a ________________________________

OR a___________________________________________

Black Hole Dense objects with gravity so strong

that not even_____________________________

Stellar Remnants White dwarfs

Core of a burned out star When it cools down it will be

called a

Neutron Stars Star of extremely high density

composed entirely of neutrons from atoms

Produced from a

___________________________________

can escape their surface

25.3- The Universe Types of Galaxies

A galaxy is a large group of stars, dust, and gases held together by gravity There are 3 types of galaxies

1. _______________________________________________________

2. _______________________________________________________

3. _______________________________________________________

1. Spiral galaxies

__________________________shaped galaxies 2 types

1. Spiral galaxy

2. ___________________________________ spiral galaxy

Contain __________________________________________________ stars

Younger stars are in the ________________________

_________________ of galaxies are spiral galaxies

2. Elliptical galaxies Range in shape from _____________________________________________

Contain only ______________________________________

About ______________ of galaxies are elliptical galaxies

3. Irregular galaxies

Have ___________________________________shapes

Contain only _________________________ stars

Only ________________ of galaxies are irregular galaxies

The Milky Way The name given to our galaxy

______________________________ galaxy

The Expanding Universe Red Shifts

Galaxies in the universe are red shifted, meaning they are

moving _________________________________________________ Earth.

A scientist by the name of ______________________________________ set out to explain why this occurred.

He realized that brighter stars must be ____________________________________ to Earth

and _______________________________ stars must be far away from Earth

He attempted to explain the red shift phenomenon by determining if a relationship

existed between____________________________________________________________________________

_______________________________________________________________________________________________

Hubble’s Law Hubble discovered that galaxies further away from Earth have a _________________________ red shift

than those closer to Earth

This means that objects move even _______________________as the get further away from Earth

This indicated that the universe is _______________________________________

The Big Bang Theory States that at one time, the entire universe was confined to a dense, hot, supermassive ball.

13.7 billion years ago, a violent explosion occurred, hurling this material in all directions

A few seconds after this big bang the universe cooled enough to allow _______________________________

______________________________________________________________________________________________________ to form

These are the building blocks for all _________________________________________

A few thousand years after the big bang _____________________________________ formed

The majority of these atoms were ________________________________________________________ atoms

Giant clouds of these hydrogen and helium atoms gathered together to form _______________________

____________________________________________________

Supporting Evidence of the Big Bang Theory1. In the 1960’s scientists discovered a type of energy called ____________________________________________

_______________________________________________. This was detected as faint _________________________________

_________________________________________ coming from every direction in space thought to be

produced during the big bang

2. There is an extremely large amount of ___________________________________________________________________ in our atmosphere

3. The galaxies in our universe are moving further away from each other. They are expanding.