Download 4.6 billion years ago - Cashmere

 The earth is old...
 Over 4.6 billion
years old!
 Scientists use a technique called
radiometric dating!
 This uses different isotopes of various
elements such as carbon (carbon
dating) and lead.
 The oldest rocks which have been
found so far are about 3.9 billion years
old.
 Some of these rocks include minerals
which are as old as 4.2 billion years.
Let’s take a look at some important
events throughout the history of the
earth
 4.6 billion years ago: earth is formed, along with
the other planets.
 3.7 billion years ago: earth's crust solidified (104).
 3.5 billion years ago: first life appears in oceans
(120).
 1.9 billion years ago: first cells with nuclei appear
in oceans (248) .
 0.65 billion years ago: first multicellular
organisms appear (348) .
 0.5 billion years ago: first land plants with inner
vessels (359) .
 245 million years ago: Dinosaurs appear (380)
 200 million years ago: Pangaea breaks up (388)
 65 million years ago: Age of Dinosaurs ends,
(394)
 3.5 million years ago: First proto-humans appear,
in Africa (3.1 cm from end)
 100,000 years ago: First Homo sapiens appears
(1 mm from end)
 10,000 years ago: Recorded human history begins
(0.1 mm from end)
the history of the earth....
in a roll of toiler paper!
400 sheets
long