By Mariam Hantera

THE DEFNETION OF Universe

The Universe is commonly defined as the totality of existence, including planets, stars, galaxies. Definitions and usage vary and similar terms include the universe, the world and nature.

The earth orbits around a very typical star we call the Sun.

Stars cluster to form galaxiesOur sun is one of over 300 billion stars in the Milky Way galaxy

Milky Way is one of 100 billion galaxies in the visible Universe

Most galaxies look like stars to us.

MERCURY Mercury is the closest planet to the sun.

It is very hot.It has a liquid outer core.It has an extremely thin atmosphere

VenusVenus is the second closest planet to the Sun.Venus is the sixth largest planet in the Solar

SystemPlanet Venus is named after the Roman

goddess of love and beauty.Similar in size, density, and mass, Venus and Earth often referred to as sister planets.

EarthOur Place in the Universe , We live on a (rather small) planet called Earth.

Earth and 7 other planets in solar system

MarsKnown as the Red Planet, Mars is

characterized by its red, dusty landscape.The diameter of the planet Mars is 6,785 kmA Mars year is equal to 686.98 Earth DaysA day in Mars is equal to 24.6 Earth Hours

Asteroids: planetesimals between Mars and Jupiter

JupiterJupiter, the largest planet in our solar

system, is 318 times larger than Earth.Jupiter’s maximum distance from the Sun =

817 million km (508 million miles)Jupiter’s minimum distance from Earth = 588

million km (365 million miles)

SaturnSaturn is the sixth planet from the Sun and the second

largest.Saturn was the god of agriculture in Roman mythology.

Saturn is also the father of Jupiter, the king of the Roman gods.

Saturn has 62 known moons, fifty-three have been named. Most of them are small in size.

Names of some of Saturn’s moons: the largest is Titan, Tethys, Dione, Rhea, & Iapetus, Mimas & Enceladus,and Hyperion.

A year on Saturn is equal to 29.5 Earth YearsSaturn is the only planet in our solar system that is less

dense that water.

UranusA year on Uranus is equal to 84.01 Earth

Years (orbit around the sun).Uranus is the third largest planet in the Solar

System.The atmosphere of Uranus is composed of

hydrogen, helium, and methane. The methane in the atmosphere absorbs red light, giving the planet a blue-green color.

NeptuneNeptune is the fourth largest planet in the Solar

System. Neptune is a gaseous planet, composed of hydrogen,

helium, methane, with traces of ammonia and water.7. The blue color of the planet is due to the

absorption of red light by methane in the atmosphere.8. The orbital speed of Neptune is 5.4 km/second.9. The diameter of Neptune is 49,493 km10. One Neptune day is equal to 16 hours in Earth

time.11. One Neptune year is equal to 164.83 Earth Years

PLUTOPluto is the farthest planet from the sun.It is very small.It is very cold there.

The Stars The number of stars in the universe today is approximately equal to the number of grains of sand on all the beaches of Earth!!

Scientific Observation

Scientific observation of the Universe, the observable part of which is about 93 billion light years in diameter, has led to inferences of its earlier stages. These observations suggest that the Universe has been governed by the same physical laws and constants throughout most of its extent and history.

THE BIG BANG THEORYThe Big Bang theory is the common or the current cosmological (study of the origin and structure of the universe) model that describes the early development of the Universe, which in physical cosmology is believed to have occurred about 13.77 billion years ago.

Did you know... Earth is the only planet in our solar system that has water in it's three states, solid, liquid and a gas.

Sally Ride—1st female in Space

The theory of relativity was developed by Albert Einstein in the early 1900s. There are two theories of relativity. The first is special relativity and the second is general relativity. Both are based on the principle of relativity, which was created by Galileo Galilei in the 1600s.