1. Spaceship Earth
An Ever Changing World

2. The Earth and Moon Viewed from Mars (May 8, 2003)
The half-Earth as seen by Mars Global Surveyor. An overlay shows the continents North and South America at the time of the exposure. Credit: NASA/JPL

3. Cosmic Calendar
Imagine that the entire history of the universe is compressed into one year - with the Big Bang corresponding to the first second of the New Year's Day, and the present time to the last second of December 31st (midnight).
Using this scale of time, each month would equal about 1.1 billion years.

4. Details Big Bang January 1 Origin of Milky Way Galaxy May 1O
Origin of the solar system September 9
Formation of the Earth September 14
Origin of life on Earth ~ September 25
Formation of the oldest rocks known on Earth October 2
Date of oldest fossils (bacteria and blue-green algae) October 9
Invention of sex (by microorganisms) ~ November 1
Oldest fossil photosynthetic plants November 12
Eukaryotes (first cells with nuclei) flourish
November 15

5. December
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday 1
Significant oxygen atmosphere begins to develop on Earth. 2 3 4 5
Extensive vulcanism and channel formation on Mars. 6 7 8 9 10 11 12 13 14 15 16
First Worms. 17
Precambrian ends. Paleozoic Era and Cambrian Period begin. Invertebrates flourish. 18
First oceanic plankton. Trilobites flourish. 19
Ordovician Period. First fish, first vertebrates. 20
Silurian Period. First vascular plants. Plants begin colonization of land. 21
Devonian Period begins. First insects. Animals begin colonization of land. 22
First amphibians. First winged insects. 23
Carboniferous Period. First trees. First reptiles. 24
Permian Period begins. First dinosaurs. 25
Paleozoic Era ends. Mesozoic Era Begins. 26
Triassic Period. First mammals. 27
Jurassic Period. First birds. 28
Cretaceous Period. First flowers. Dinosaurs become extinct. 29
Mesozoic Era ends. Cenozoic Era and Tertiary Period begin. First cetaceans. First primates. 30
First evolution of frontal lobes in the brains of primates. First hominids. Giant mammals flourish. 31
End of Pliocene Period. Quaternary (Pleistocene and Holocene) Period. First humans.
One day = 37 million years

6. December 31 One hour = 1.6 million years
One minute = 26 thousand years
One second = 431 years
Origin of Proconsul and Ramapithecus, probable ancestors of apes and men
~ 1:30 p.m.
First humans
~ 10:30 p.m.
Widespread use of stone tools
11:00 p.m.
Domestication of fire by Peking man
11:46 p.m.
Beginning of most recent glacial period
11:56 p.m.
Seafarers settle Australia
11:58 p.m.
Extensive cave painting in Europe
11:59 p.m.
Invention of agriculture
11:59:20 p.m.
Neolithic civilization; first cities
11:59:35 p.m.
First dynasties in Sumer, Ebla and Egypt; development of astronomy
11:59:50 p.m.
Invention of the alphabet; Akkadian Empire
11:59:51 p.m.
Hammurabic legal codes in Babylon; Middle Kingdom in Egypt
11:59:52 p.m.

7. December 31 One hour = 1.6 million years
One minute = 26 thousand years
One second = 431 years
Bronze metallurgy; Mycenaean culture; Trojan War; Olmec culture; invention of the compass
11:59:53 p.m.
Iron metallurgy; First Assyrian Empire; Kingdom of Israel; founding of Carthage by Phoenicia
11:59:54 p.m.
Asokan India; Ch'in Dynasty China; Periclean Athens; birth of Buddha
11:59:55 p.m.
Euclidean geometry; Archimedean physics; Ptolemaic astronomy; Roman Empire; birth of Christ
11:59:56 p.m.
Zero and decimals invented in Indian arithmetic; Rome falls; Birth of Islam and the Islamic Civilization
11:59:57 p.m.
Mayan civilization; Sung Dynasty China; Byzantine empire; Mongol invasion; Crusades
11:59:58 p.m.
Renaissance in Europe; voyages of discovery from Europe and from Ming Dynasty China; emergence of the experimental method in science
11:59:59 p.m.
Widespread development of science and technology; emergence of global culture; acquisition of the means of self-destruction of the human species; first steps in spacecraft planetary exploration and the search of extraterrestrial intelligence
Now: The first second of New Year's Day

8. 1.1 billion years ago (late pre-Cambrian)

9. Cambrian: the beginning of the Paleozoic Era
Animals with hard-shells appeared in great numbers for the first time during the Cambrian.  The continents were flooded by shallow seas.  The supercontinent of Gondwana had just formed and was located near the South Pole.

10. Ancient Oceans Separate the Continents
                                                                                                                                                                                                                   
During the Ordovician ancient oceans separated the barren continents of Laurentia, Baltica, Siberia and Gondwana.  The end of the Ordovician was one of the coldest times in Earth history.  Ice covered much of the southern region of Gondwana.

11. The Devonian Was the Age of Fish!
                                                                                                                                                                                                                   
By the Devonian the early Paleozoic oceans were closing, forming a "pre-Pangea".  Freshwater fish were able to migrate from the southern hemisphere continents to North America and Europe.  Forests grew for the first time in the equatorial regions of Artic Canada.

12. During the Early Carboniferous Pangea Begins to Form.
                                                                                                                                                                                                        
During the Early Carboniferous the Paleozoic oceans between Euramerica and Gondwana began to close, forming the Appalachian and Variscan mountains.   An ice cap grew at the South Pole as four-legged vertebrates evolved in the coal swamps near the Equator.

13. The Late Carboniferous a Time of Great Coal Swamps
By the Late Carboniferous the continents that make up modern North America and Europe had collided with the southern continents of Gondwana to form  the western half of Pangea.  Ice covered much of the southern hemisphere and vast coal swamps formed along the equator.

14. At the end of the Permian was Greatest Extinction of All Time
                                                                                                                                                                                                        
Vast  deserts covered western Pangea during the Permian as reptiles spread across the face of the supercontinent.  99% of all life perished during the extinction event that marked the end of the Paleozoic Era.

15. At the end of the Triassic, Pangea began to rift apart.
The supercontinent of Pangea, mostly assembled by the Triassic, allowed land animals to migrate from the South Pole to the North Pole.  Life began to rediversify after the great Permo-Triassic extinction and warm-water faunas spread across Tethys.

16. Early Jurassic, the Dinosaurs spread across Pangea
                                                                                                    
By the Early Jurassic, south-central Asia had assembled.  A wide Tethys ocean separated the northern continents from Gondwana.  Though Pangea was intact, the first rumblings of continental break up could be heard.

17. Pangea Begins to Rift Apart
The supercontinent of Pangea began to break apart in the Middle Jurassic.  In the Late Jurassic the Central Atlantic Ocean was a narrow ocean separating Africa from eastern North America.   Eastern Gondwana had begun to separate form Western Gondwana.

18. New Oceans Begin to Open
During the Cretaceous the South Atlantic Ocean opened.  India separated from Madagascar and raced northward on a collision course with Eurasia. Notice that North America was connected to Europe, and that Australia was still joined to Antarctica.

19. The World Assumes a Modern Configuration
20 million years ago, Antarctica was coverd by ice and the northern continents were cooling rapidly.  The world has taken on a "modern" look, but notice that Florida and parts of Asia were flooded by the sea.

20. The Earth has been in an Ice House Climate for the last 30 million years
When the Earth is in its "Ice House" climate mode, there is ice at the poles.  The polar ice sheet expands and contacts because of variations in the Earth's orbit (Milankovitch cycles).  The last expansion of the polar ice sheets took place about 18,000 years ago. 

22. The Atlantic Ocean begins to Close
New subduction zones along the eastern coasts of North America and South America will begin to consume the ocean floor separating North America from Africa.  About 100 million years from now the present-day Mid-Atlantic Ridge will be subducted and the continents will come closer together.

23. "Pangea Ultima" will form 250 million years in the Future

24. Earth’s Climate Throughout History