Cruise questions .

_ how is the weather at the moment?
_ have you ate yet?
_ what are your plans for today?

Geologic Time Scales

1] What were three major geologic events in the history of the Earth?
_ humans appearing on earth
_ dinosaurs
_volcano eruptions

2] How many Eras, Eons ( periods or epochs ) are there?
_ 4 Eras , 12 Periods , 11 Epochs.

3] What do you think are the differences between Eras / Eons?
_ Eon, Era & Epoch are 3 different geochronological unities.
_ Eon is first, Era is the second, Epoch are the fourth.
_ Between an ara and an epoch there is a Period*

4] Why did scientist create Eras and Eons in the first place?
_Scientist created Eras & Eons to describe the timing and relationships between events that have occurred throughout Earth's history.

Hertzsprung - Russell Diagram

_ Why is the Hertzsprung - Russell Diagram important to astronomy?
Astronomers are able to determine these values and many other characteristics that are of interest to both the scientists and public. 

_What are the two qualities of a star does the HR Diagram measure, and how does the diagram do this?
 It plots the luminosity and temperature. 

_Where on the diagram would our sun be found?
The sun would be found around the 5,000 K and 5 + magnitude. 

Haiku

I appreciate,
The distance in space and size,
It is amazing.