Intro to Astronomy - Chapter 1 Lecture Notes
All other elements were constructed from hydrogen and helium in stars and then........
....... recycled into new star systems, including our solar system
Star
glowing ball of gas that generates heat and light through nuclear fusion
Dark matter
one of the greatest mysteries in astronomy
Light Year
the distance light can travel in 1 year
The more ______________ the galaxy, the _______________ it is racing away
the more distant the galaxy, the faster it is racing away
Crab Nebula
the relic of the death of a massive star as a supernova
Universe
the sum total of all matter, and energy; that is, everything within and between all galaxies
How often does Earth complete its orbit?
Once every year
How often does Earth rotate around it's axis?
Once everyday
Our sun moves _______________ to the other stars in the local solar neighborhood.
Our sun moves randomly relative to the other stars in the local solar neighborhood
Where does most of the milky way's light comes from what?
from it's disk and bulge
How fast does light take to travel from the Earth to Sirius?
8 years
Solar (Star) System
- our solar system is made of all the stuffs mention above - planets are the most prominent members (except the central star) - it's not necessarily that every star has such as a planetary system - there are many, many other similar systems in our milky way
Light year formula is?
1 light year = (speed of light) x (1 year) (300,000 km/s) x (365 days/1 year x 24 hours/1 day x 60 minutes/1 hour x 60 seconds/1 minute) = 9,460,000,000,000 km
How fast does light take to travel from the Earth to the Moon?
1 second
What is the size of the universe?
14 billion light years in radius and contains over 100 billion galaxies
How fast does light take to travel from Earth to Andromeda Galaxy?
2. 5 million years
Light travels at a finite speed of?
300,000 km/s
How fast does light take to travel from the Earth to the Sun?
8 minutes
At great ___________, we see objects as they were when the universe was much ______________.
At great distances, we see objects as they were when the universe was much younger.
Order the Earth, milky way galaxy, universe, solar system, local supercluster, and local group in order from smallest to largest?
Earth ---> Solar System ----> Milky Way Galaxy ---> Local Group----> Local Supercluster----> Universe
What is the size of the Earth if the solar system in a 1 to 10 billion scale?
Earth is the size of a ball point 15 meters
How often do we the galaxy?
Every 230 million years
What is the size of the sun if the solar system in a 1 to 10 billion scale?
The Sun is the size of a large grapefruit
The_______ away we look in distance, the __________ back we look in time.
The farther away we look in distance, the further back we look in time
Which part of Earth rotates the fastest?
The middle part of Earth
What is discovered about our universe?
We live in an expanding universe
Galaxy
a great island of stars in space, all held together by gravity and orbiting a common center
Planet
a moderately large object that orbits a star; it shines by reflected light. Planets may be rocky, icy, or gaseous in composition
Comet
a relatively small and icy object that orbits a star
Asteroid (minor planet)
a relatively small and rocky object that orbits a star
Cosmic Calendar
a scale on which we compress the history of the universe into 1 year
Orion nebula
a typical example of a "stellar nursery" - hosts several hundreds of young stars
How many galaxies are there?
about 100 billion galaxies
How many stars are in the Milky Way?
about 100 billion stars
All _______________ outside our local group are moving _____________ from us.
all galaxies outside our local group are moving away from us.
Nebula
an interstellar cloud of gas and dust, site of stars' birth or death
Moon (Satelliete)
an object that orbits a planet
Why do nebulas' shine?
because of the star(s) embedded within
What direction does earth rotate?
counterclockwise
What are also important components of galaxies?
diffused gas and dust in between stars
