The Amazing Universe

Unraveling the mysteries of our UNIVERSE

Made byGovind Joshi

Introduction

The Universe is everything that exists, including objects and energy throughout time and space. The size of the universe is difficult to imagine. It is so large that even light (travels 299,792, 458 m/s) from very distant objects in the universe must travel billions of years before reaching the earth. The earth, sun, and the moon are only a small part of the universe. Another name for the universe is “Cosmos”. That is the reason Cosmology and Astronomy are both the study of the universe. Astronomers are scientists that study the universe. They use telescopes and many other tools to study the universe. They also use information collected during space exploration and by satellites.

HOW THE UNIVERSE WAS FORMED

The Big Bang Theory

The Big BangMost Scientists believe that the universe began suddenly in an event called the “Big Bang”. They estimate this event happened between 10 to 15 billion years ago. At the time of the big bang, the matter was tightly packed and hot. After the big bang the matter began cooling and expanding. Within minutes, particles of matter formed atoms of hydrogen and helium. These atoms later formed stars which lead to the creation of planets. Since then the universe has been cooling and expanding. Some astronomers think that the universe may stop expanding and start contracting, but most astronomers think that it will keep expanding.

GALAXIES, STARS, AND PLANETS

What is a Star ? How is a star formed ? Different types of stars

How are planets formed ? What is a Galaxy ?

What is a Star ?

A star is a huge sphere of very hot, glowing gas. Stars produce their own light and energy by a process called nuclear fusion. Fusion happens when lighter elements are forced to become heavier elements. When this happens, a tremendous amount of energy is created causing the star to heat up and shine. Stars come in a variety of sizes and colors. Our Sun is an average sized yellowish star. Stars which are smaller than our Sun are reddish and larger stars are blue.

How is a star formed ? Clouds of gas (nebula) are

disturbed by the gravity of a nearby phenomena. This disturbance causes clumps to form and draw gas inward. The collapsing clump begins to rotate and flatten into a disc of gas and dust. The disc rotates faster and faster pulling more material inward creating a hot, dense core called a protostar. When the protostar becomes hot enough, it starts producing helium and energy. If enough mass collapses into the protostar, a bipolar flow occurs. Two massive gas jets erupt from the protstar and blast the remaining gas and dust clear away from its fiery surface. A Star is born.

Different types of Stars

Have you observed a candle before ? Well, look at it carefully. The outermost part of the fire looks red (not so hot), the middle part looks yellow (medium hot), and the innermost part looks blue (Very Hot).Similarly, red stars are not so hot, yellow stars are medium hot, and blue stars are very hot. These are the different types of stars :

Yellow Star Black Holes White Dwarf Blue StarsGiant StarNeutron StarSupergiant StarRed Dwarf

Not so hot

Medium hot

Very hot

Yellow Stars

Our Sun is a yellow star. Yellow Stars are medium-sized stars and they look yellow because they have a medium temperature. They burn their fuel fast so they live up to 10 billion years.

Giant Stars and White Dwarfs

Stars with up to 3 times the mass of the sun continue fusing hydrogen into helium in their outer layers. Therefore the hull heats up and is driven out into space. The star expands and increases brightness. A Giant star is evolved. The core is left behind as White dwarf which burns very little fuel and slowly fades away.

Giant Star

White DwarfNote- White Dwarfs go Nova. A star showing a sudden large increase in brightness and then slowly returning to its original state over a few months.

Supergiant Stars and Blue Stars

Supergiant stars are nothing but stars that expanded and increased their brightness massively. Blue Stars are very large and compact. They burn their fuel very quickly so they are very hot. Sometimes these stars can run out fuel in only 10,000 years. Both of these stars die in a spectacular way. They supernova (massive explosion) which can be seen from galaxies away. Or they shrink into black holes or neutron stars

Supergiant Star

Blue Star

Black holes and Neutron Stars Stars are sustained by the

nuclear fusions going on in their core from their own gravity. After they run out of almost all their fuel, they collapse into their own gravity. How much mass the star had when it died determines what it becomes. Stars with up to 3 times the mass of the sun become neutron stars. These stars are very dense, they spin very fast, they do not glow, and are made mostly of neutrons. Stars with the mass of over 3 times the sun get crushed to a single point called a black hole.

Black Holes have so muchGravitational pull that evenLight cannot escape the wrathof black holes.

Black Hole

Neutron Star

Red Dwarfs

Red Dwarfs are small stars that burn a little more fuel than white dwarfs. They have a mass of less than half that of the Sun. They are relatively cooler than most stars. Proxima Centauri , the nearest star to the Sun, is a red dwarf.

Proxima Centauri Red Dwarf

How are planets formed ? Planets are formed out of the

remnants of a star birth. When a star is in the initial stages of being created, the molecular cloud surrounding it begins to rotate. As it rotates, the cloud will begin to condense around areas where there is more matter. These are called “protoplanets. These protoplanets will continue to accumulate more matter by their gravitational pull which will keep increasing as they get bigger. Once the star is born, it will blow away the remnants of the cloud leaving only the protoplanet. Depending on its size, the protoplanet will become a moon, asteroid, comet, or planet.

Planet Forming

What is a Galaxy ?

The sun is in a group of stars known as the Milky Way galaxy. A galaxy is a large system of stars, gas, planets, asteroids, and dust. The Milky Way galaxy alone contains more than a 100 billion stars. Some galaxies are larger, and some are much smaller. But even small galaxies contain hundreds of millions of stars. Galaxies also have many different shapes. The Milky Way galaxy looks like a milk spill. Until the early 1900s scientists did not know that there were galaxies outside the Milky Way. By using powerful telescopes, scientists now estimate that there are over billions of galaxies in the universe. The Andromeda galaxy is the closest galaxy to the Milky Way.

The Milky Way Galaxy

The Andromeda

GalaxyThe Andromeda galaxy is a spiral galaxy and it

contains about 1 trillion stars

The Solar System

The Solar System The Planets and their moons The Earth’s moon Asteroids and comets

The Solar System The Solar System

consists of the Sun, Moon, and Planets. It also consists of comets, meteoroids, and asteroids. The Sun is the largest member of the Solar System. In order of distance from the Sun, the planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto; the dwarf planet. The Sun is at the center of the Solar System and the planets, asteroids, comets and meteoroids revolve around it.. Other planets that orbit other stars are called exoplanets.

The Solar System

The Planets and their Moons

These are all the planets in order (distance from the sun) :

Inner Planets (made of rock) Mercury Venus Earth Mars Outer Planets (made of gas) Jupiter Saturn Uranus Neptune

Inner Planets

MERCURY 1 Orbit of Sun-87.969 Days 1 Rotation-58.6461 Days Distance from Sun-57 million km Moons-0

EARTH 1 Orbit of Sun-365.3 Days 1 Rotation-23 hrs. 56 min Distance from Sun-150 million km Moons-1

VENUS 1 Orbit of Sun-224.701 Days 1 Rotation-243.16 Days Distance from sun-107 million km Moons-0

MARS 1 Orbit of Sun-686.98 Days 1 Rotation- 1.37 day Distance from sun-229 million km Moons-3

Outer Planets

JUPITER 1 Orbit of sun-4332.59 Days 1 Rotation-9 hrs. 55 min Distance from sun-777 million km Moons- 63

URANUS 1 Orbit of sun-30684 Days 1 Rotation-17.2 hrs. Distance from sun-2871 million

km Moons- 27

SATURN 1 Orbit of sun-10759.2 Days 1 Rotation-10 hrs. 13 min Distance from sun-1429 million km Moons- 47

NEPTUNE 1 Orbit of sun-60190 Days 1 Rotation-16 hrs. 17 min Distance from sun-4496 million km Moons- 13

Outer Planets

The Earth’s Moon

The Moon is a barren, rocky world without air and water. It has dark lava plains on its surface. The Moon is filled with craters. It has no light of its own. It gets its light from the Sun. The Moon looks like it is changing its shape as it moves round the Earth. It spins on its axis in 27.3 days. Neil Armstrong and Edwin Aldrin were the first ones to set their foot on the Moon on 21 July 1969 They reached the Moon in their space craft named Apollo II.

The Moon

Asteroids and Comets

Asteroids and comets are considered remnants from the giant cloud of gas and dust that condensed to create the sun, planets, and moons some 4.5 billion years ago. Today, most asteroids orbit the sun in a tightly packed belt located between Mars and Jupiter. Comets are relegated to either a cloud or belt on the solar system fringe. Gravitational tugs, orbital collisions, and interstellar jostles occasionally perturb an asteroid or comet onto a wayward path.

Asteroid

Comets

More Pictures

Light from a nearby Supergiant Star

Largest Black hole known to man

Nebula

Black Hole eating a huge star

Crab NebulaBiggest Nebula knownTo man

That is not everything !

There is a lot more to learn about the universe and a lot of mysteries to solve. So I hope you enjoyed the show ! Horsehead Nebula

Millions of different galaxies