History of the universe

Solar system or Milky Way

1 CE

The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye.

Big Bang event

1 CE

The universe began, scientists believe, with every speck of its energy jammed into a very tiny point. This extremely dense point exploded with unimaginable force, creating matter and propelling it outward to make the billions of galaxies of our vast universe

Sun

4

The sun was born about 4.6 billion years ago. Many scientists think the sun and the rest of the solar system formed from a giant, rotating cloud of gas and dust known as the solar nebula. As the nebula collapsed because of its gravity, it spun faster and flattened into a disk.

Moon

4

The leading theory of the Moon's origin is that a Mars-sized body collided with Earth approximately 4.5 billion years ago, and the resulting debris from both Earth and the impactor accumulated to form our natural satellite. The newly formed Moon was in a molten state.

Unicellular life

4

A unicellular organism, also known as a single celled organism. ,
unlike a multicellular organism that consists of multiple cells.All prokaryotes are unicellular and are classified into bacteria and archaea. Many eukaryotes are multicellular, but some are unicellular such as protozoa, unicellular algae, and unicellular fungi. Unicellular organisms are thought to be the oldest form of life, with early photocells possibly emerging 3840 billion years ago.[

Earth

4

Earth formed around 4.54 billion years ago, approximately one-third the age of the universe, by accretion from the solar nebula. Volcanic outgassing probably created the primordial atmosphere and then the ocean, but the early atmosphere contained almost no oxygen.

Multicellular life

4

Large, multicellular life forms may have appeared on Earth one billion years earlier than was previously thought. Macroscopic multicellular life had been dated to around 600 million years ago, but new fossils suggest that centimeters long multicellular organisms existed as early as 1.56 billion years ago

Dinosaurs

700

Dinosaur fossils have been found on all seven continents. All non-avian dinosaurs went extinct about 66 million years ago. There are roughly 700 known species of extinct dinosaurs. Modern birds are a kind of dinosaur because they share a common ancestor with non-avian dinosaurs

Humans

900

Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa. Most scientists currently recognize some 15 to 20 different species of early humans.