History of universe

The Big Bang

138,000 BCE

The big bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now—and it is still stretching!

Earth

100,000 BCE

About 1,000,000,000 years ago, Earth had its first signs of life. Single-celled organisms consumed the sun’s energy. As a waste product, these cyanobacteria eventually filled the oceans and atmosphere with oxygen. Next, an oxygenated atmosphere paved the way for more complex life forms to exist. At about 100,000,000 years ago, dinosaurs roamed the Earth until their abrupt extinction.

Moon

100,000 BCE

Earth has just one moon – a rocky, cratered place, roughly a quarter the size of Earth and an average of 238,855 miles away. The Moon can be seen with the naked eye most nights as it traces its 27-day orbit around our planet.

Sun

2000 BCE

The Sun’s volume would need 1.3 million Earths to fill it. Its gravity holds the solar system together, keeping everything from the biggest planets to the smallest bits of debris in orbit around it. The hottest part of the Sun is its core, where temperatures top 27 million degrees Fahrenheit (15 million degrees Celsius). The Sun’s activity, from its powerful eruptions to the steady stream of charged particles it sends out, influences the nature of space throughout the solar system.

Solar System or milky way

1000 BCE

Like early explorers mapping the continents of our globe, astronomers are busy charting the spiral structure of our galaxy, the Milky Way. Using infrared images from NASA's Spitzer Space Telescope, scientists have discovered that the Milky Way's elegant spiral structure is dominated by just two arms wrapping off the ends of a central bar of stars. Previously, our galaxy was thought to possess four major arms.

Unicellular Life

800 BCE

A unicellular organism is an organism that consists of a single cell. This means all life processes, such as reproduction, feeding, digestion, and excretion, occur in one cell. Amoebas, bacteria, and plankton are just some types of unicellular organisms. They are typically microscopic and cannot be seen with the naked eye.

Multicellular Life

700 BCE

The first known single-celled organisms appeared on Earth about 3.5 billion years ago, roughly a billion years after Earth formed. More complex forms of life took longer to evolve, with the first multicellular animals not appearing until about 600 million years ago. The evolution of multicellular life from simpler, unicellular microbes was a pivotal moment in the history of biology on Earth and has drastically reshaped the planet’s ecology.

Dinosours

600 BCE

The prehistoric reptiles known as dinosaurs arose during the Middle to Late Triassic Period of the Mesozoic Era, some 230 million years ago. They were members of a subclass of reptiles called the archosaurs (“ruling reptiles”), a group that also includes birds and crocodiles. Scientists first began studying dinosaurs during the 1820s, when they discovered the bones of a large land reptile they dubbed a Megalosaurus (“big lizard”) buried in the English countryside.