Class Notes- Unit 1-2 Flashcards
What is absolute time?
when an event occurred…its age, measured backwards from the present.
What is the range of the age of rocks on Earth?
from 0 years old (deposited today) to 4.1 billion years old.
How old is the earth?
about 4.57 billion years old
What is relative time?
the sequence of events, regardless of knowing the actual age.
What 4 things is relative time used for?
1) stratigraphic succession…superposition
2) cross-cutting structures
3) deformation
4) fossil succession
What are the 4 ways we can write the Earth’s age?
1) 4.57 billion
2) 4.57 x 10^9
3) 4.57 Ga
4) 5, 470 Ma
How far is the Earth from the sun?
150 million km OR Sun to Earth ~ 150 x 10^6 km
What does AU stand for?
Astronomical units
How far is the Sun to Earth measured with AU?
1 AU
What is the distance from Mars to Sol measured with AU?
1.5 AU
What is the distance from Jupiter to the Sun measured with AU?
5.2 AU
What are light years
The distance travelled by light in one Earth year of 365 1/4 days, in a vacuum.
What is the distance travelled in a years with light years?
= 9.46 trillion km
= 9.46 x 10^12 km
How fast does light travel?
300 million meters per second OR 300 x 10^6 m/s OR 300 x 10^3 km/s
How far apart is the sun and earth measured in light years?
8 min
What is the next closest galaxy to the Milky Way galaxy?
Andromeda Galaxy
How long does it take for us to see light from Andromeda Galaxy?
light left that galaxy at ~ 2.5 x 10^6 ly (2.5 million years ago)
How many full bodied planets are there?
8
How many planets have moons?
7
How much of the material that makes up the solar system is in the sun?
greater than 99%
How much material that makes up Jupiter of the less than 1% not in the sun?
about 99% of the remaining less than 1% that is not in the sun.
What takes up the less than 1% of the stuff not in Jupiter or the sun of our solar system?
the other planets
What is our universe composed of?
galaxies
How many galaxies is there estimated to be in our universe?
1 trillion
What is each galaxy composed of?
stars
What is the average amount of stars per galaxy?
300 billion
What are nebulae?
clusters in or galaxy composed of interstellar gas and dust
What is a supernova?
the result of giant stars having exploded
What type of galaxy is the Milky Way galaxy?
a spiral galaxy
How many exoplanets have been discovered?
1000 discovered
2000 probably
Do galaxies tighten or loosen with time?
tighten with time
What do galaxies do in the expanding universe?
separate from one another.
How far back did the galaxies converge at a common point?
they find that the galaxies converge at a common point 13.7 billions years ago
What type of factories are our stars?
thermo-nuclear factories
What do thermonuclear factories (our stars) do?
they manufacture energy
What is the explosion of stars (thermo-nuclear factories) due to?
the energy release by nuclear fusion.
Stars come in a range of___and___
size and mass
Is our sun slightly larger and heavier or smaller and lighter than the average star?
larger
Solar___is important to the job of being an element factory?
mass
What does solar mass equal?
1
What is the solar mass of our sun?
SM1
What is the solar mass of the heaviest stars?
~ SM100 or more
Largest stars have a volume of or a___times SOL
a million times and over 100 times the mass
What is the basic unit of the entire universe?
stars
What does our solar system orbit?
stars
What are the two ways to talk about stars?
diameter and mass
What is the range of solar masses?
1/10M to 1M to 10M to 100M
True or False: Stars and dynamic, ever changing and the size can vary with time.
True
What are stars?
Large bodies of mostly ‘plasma’ and free electors (thermo-nuclear factories)
What are the features of stars that are easily seen or measured?
- mass
- size
- colour
- temperature
What controls a star?
its mass
What colour are cold stars? Hot stars?
cold=red
hot=blue
How do stars evolve?
form and later decay (explode)
What is a supernova?
Gravity holds particles back because they are exploding all the time. When gravity can’t hold it back, it dies.
-It is the violent, explosive death of a star.
What are stars made out of?
Mostly H (75% H, 25% HE)
Are all stars composed equally?
no
What are the two dominant forces in our universe?
gravity and thermo-nuclear energy
What type of force is gravity?
an attractive force
What is the main force of accretion?
gravity
What type of force is thermo-nuclear energy?
a repulsive force
True or False: thermo-nuclear energy can be fission or fusion?
true
___is important for star evolution (fission or fusion)
fusion
What are the two requirements for star evolution?
pressure (gravity) and high temperature.
What is nuclear fusion with stars?
Atomic nuclei fuse together to form new elements–heavier elements.
What goes on inside stars and produces new elements?
Nuclear fusion
Stars are___nuclear-factory.
thermo
What happens when a stars explodes?
Become a supernova and remnant core, these elements are scattered through a considerable volume of space.