The Beginning of the Universe

• The universe was created 12-14 billion years ago in an event known as the big bang

• The universe started at an incredibly small volume

• It rapidly expanded and cooled• four fundamental forces (gravity,

electromagnetism, and the strong and weak nuclear forces) were created

The beginning of The galaxy

• The young universe did not have a perfectly even distribution of energy and particles.

• Concentrations of matter formed into clouds, then condensed into stars and the collections of stars we call galaxies.

• We live in a Galaxy known as the Milky Way

The Birth of the Solar System

• The most prevalent theory is the Nebula theory.

• Nebula: an interstellar cloud of dust, hydrogen gas and plasma

• An explosion from a nearby star

caused the nebula to compress

and Rotate

• Birth 5 billion years ago

The solar system continued

• The center ball became the sun

• The rest of the disc condensed into rings of dust and gas

• The solar winds blew the lighter gases to the other rings.

• Gravity caused the rings to collect and form planets

Some important terms

• Light years or minutes (the amount of time light takes to travel such a distance)

• When we see a star 4 light years away, we are actually seeing what it looked like 4 years ago

• Year: The time it takes a planet to orbit the sun.

• Day: The time it takes a planet to rotate 360 degrees.

The Sun

• Is a star like the millions of other stars in the universe

• It is 8 light minutes away• The nearest star after the sun is 4.3 light

years away.• The sun is mainly composed of H and He.• It behaves like an immense nuclear

reactor, that will eventually run out of fuel• 5770 C at the surface

Review

• The Universe was created 12 – 14 billion years ago in an event called the big bang

• We live in a galaxy called the milky way.

• The solar system was created 5 billion years ago by an event called the Nebula Theory.

Review Continued

• The Sun is a star composed mainly of Hydrogen and Helium

• It is a nuclear reaction inside the sun is what keeps it shinning. The sun will eventually run out of fuel.

The search for life

• Is there life on other planets?

• What would the life form look like?

• What adaptations are necessary?

• This subject has gathered much interest by the scientists.

Necessities of Life

• Scientist are currently searching extreme environments on earth to see if the can find life.

• The organisms that inhabit these extreme environments are known as extremophiles.

• There are 3 basic necessities for life.– Liquid water– Other elements– A stable environment

Where should we Search for life?

Let’s take a look at our solar system.

The Planets

• The planets are divided into 2 types:– terrestrial– Jovian (gas Giants)

• There are eight planets that rotate around the sun.

• One dwarf planet (Pluto)

and one unclassified object (Sedna).

Here’s how you remember the Planets and their order.

• My Very Educated Mother Just Served

Us Nine Pieces of Sushi.

• Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, Sedna

• All the planets orbit in an almost circular orbit and in the same plane. (exception Sedna)

• Pluto orbit is off by 17 degrees

The terrestrial planets

• Consist of the four planets closest to the sun: Mercury, Venus, Earth and Mars.

• Small in size compared to gas giants.

• Compact and Rocky• Made mostly of heavy

elements• Few moons.

Mercury

• Closest to the sun.

• No Atmosphere

• Surface is covered in Craters

• Temperatures up to 350 degrees Celsius on light side

• Temperatures as low as -170 degrees on dark side

Venus

• Has a thick atmosphere

composed mostly of CO2

creating the greenhouse effect

• Temperatures as high as 480 degrees Celsius

• Volcanic Surface

Earth

• Only planet known to contain life

• 75 % of the surface is made up of water

Mars

• It is called the red planet because it is covered in rusted Iron• Contains the solar system’s

biggest volcano (known as Olympus Mons)

• Atmosphere consisting of CO2• It is believed that it may have had life earlier on.• There are signs that there once was liquid water.• Is the most similar planet to Earth.

Exploring Mars

• Mars has been extensively studied

• Currently NASA would like to see if there is liquid water at the polar ice caps

The Phoenix Mission

Day 1: Phoenix lands on Mars: Searching the Polar Ice caps

• The Phoenix landed on Mars Sunday

• Here is a picture• Icy ground

Asteroid Belt

• Separates the Terrestrial Planets and Gas Giants.

The Gas Giants

• Very big• Strong gravity and therefore have numerous

moons• Farther from the sun, cooler• All have atmosphere• Atmosphere mostly composed of Hydrogen and

helium• No solid surface• Consist of Jupiter, Saturn, Uranus and Neptune.

Jupiter

• Biggest planet in the solar System

• One day = 9 hours and 55 minutes

• However a year = 11.9 earth years

• Has 16 moons

• One such moon is

Europa

Europa• Scientists are

fascinated by this moon belonging to Jupiter.

• an atmosphere consisting of Oxygen

• Believed to have Liquid water beneath the Ice covered surface.

• There are possibilities for life on this moon

Saturn

• It is surrounded by immense rings of rock and ice

• The planet is less dense than water, and would float if dropped in a large ocean

• Made up of Hydrogen and Helium

Uranus

• Atmosphere of Hydrogen, Helium and Methane

• Methane gives it its blue color

Neptune

• Twin Planet of Uranus, similar size and atmospheric composition

Pluto (dwarf planet)

• Smallest planet

• Furthest planet

• Takes over 248 years to orbit the sun.

Sedna

• The object is three times farther away from Earth than Pluto, making it the most distant known in the solar system.

• It takes10,500 years to orbit around the Sun

• Currently it is unclassified.

What is a satellite?

• A natural satellite (a moon) is a celestial body that revolves around a planet.

Years on other PlanetsPlanet Distance

from Sun (millions Km)

Duration of year

Temperature degrees Celsius

Mercury 57.9 88 days 127

Venus 108.2 224.7 days 462

Earth 149.6 365.3 days 15

Mars 227.9 687 years -63

Jupiter 778.4 11.86 years -148

Saturn 1 427 24.46 years -178

Uranus 2 871 84 years -216

Neptune 4 498 165 years -214

Trends

• The further the planet is from the sun, the longer it takes the longer the year.

• Generally the further the planet, the cooler the surface temperature (depends also on atmosphere).

What keeps the planets orbiting around the Sun?

• The gravity from the sun, keeps the planets revolving around the sun.

• Similarly when you drop an object on earth, gravity pulls the object towards the center of the earth.

Comets

• A ball of snow, ice, rock and dust.

• Most comets revolve around the sun.

• When the comet passes near the sun, the ice Sublimates and the gases disperse creating a tail.

Solar eclipse

• Occurs when the moon has moved to a place that is exactly between the earth and the sun.

Lunar Eclipse

• A lunar eclipse occurs when the Earth is exactly between the sun and the Moon.

• The moon becomes masked by the shadow of the earth.