OUR SOLAR SYSTEM

SOLAR SYSTEM OVERVIEW

OUR SOLAR SYSTEM INCLUDES: ●SUN●EIGHT PLANETS & THEIR SATELLITES●THREE DWARF PLANETS●ASTEROIDS●COMETS●METEOROIDS

THE PLANETSJUPITER SATUR

N

URANUS

NEPTUNE

EARTH

PLUTO

ADD THE SUN

HOW SMALL ARE WE?

ASTEROIDS

Most lie between Mars and Jupiter●Microplanets: small, rocky bodies●Irregular shapes

●Large, "dirty snowballs"●Composition:

●Frozen gases●Rocky and metallic materials

●Produces a glowing head called the coma and a tail that points away from the sun

COMETS

COMET HALE-BOPP

METEOROIDSMETEOROID – small solid particle that travels through spaceMETEOR – when a meteoroid enters Earth’s atmosphere, “shooting star”METEORITE – when a meteoroid reaches the Earth’s surface

WHICH ONE OF THESE IS NOT LIKE THE OTHERS?

RIGHT! PLUTO

DOES NOTBELONG…

THREE MAIN CATEGORIES OF OBJECTS IN OUR SOLAR

SYSTEM: 1. PLANETS: The eight worlds starting with Mercury and moving out to Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune.

2.SMALL SOLAR SYSTEM BODIES: All other objects orbitingthe sun.

3.DWARF PLANETS: Pluto and any other round object that "has not cleared the neighborhood around its orbit, and is not a satellite."

EARLY HISTORY OF ASTRONOMY

ASTRONOMY: the study of the UNIVERSEANCIENT GREEKS – Golden age of early astronomy

• Used geometry and trigonometry to measure sizes and distances of the sun and moon

• ARISTOTLE – the Earth is round• GEOCENTRIC MODEL –Earth is the center

EARLY HISTORY OF ASTRONOMY

Birth of modern astronomy 1500s and 1600sFive noted scientists

1. NICOLAUS COPERNICUS (1473-1543)⚫Concluded Earth was a planet⚫HELIOCENTRIC MODEL – Sun is the center

EARLY HISTORY OF ASTRONOMY

2. TYCHO BRAHE (1546-1601) ●Made most precise observations

Early History of Astronomy3. JOHANNES KEPLER (1571-1630)

●Planets revolve around the Sun●Three laws of planetary motion

EARLY HISTORY OF ASTRONOMY

4. GALILEO GALILEI (1564-1642) ●Constructed a telescope and saw the universe in a new way

●Discovered:●Four moons of Jupiter●Planets appeared as disks●Phases of Venus●Features on the Moon●Sunspots

EARLY HISTORY OF ASTRONOMY

5. SIR ISAAC NEWTON (1643-1727)●Law of universal gravitation●Explained planetary motion

TELESCOPESTools used to help astronomers see CELESTIAL (space)

objects with greater detail by:

1. GATHERING MORE LIGHT than your eye can (dim objects are easily seen)2. MAGNIFYING IMAGES to separate distant objects from one another

HUBBLE SPACE TELESCOPEOVER 350 MILES FROM EARTH

Hubble Space Telescope Size:Length: 43.5 ft (13.2 m)Weight: 24,500 lb (11,110 kg)Maximum Diameter: 14 ft (4.2 m)Hubble is nearly the size of a large school bus—but it can fit inside a space shuttle cargo bay.

HUBBLE FOUND THAT GALAXIES ARE SPEEDING AWAY FROM EACH OTHER,

CONSISTENT WITH A GENERAL EXPANSION OF THE UNIVERSE.

THIS IS CALLED THE BIG BANG.

DEEP SPACE IMAGE

OPTICAL TELESCOPES Use lenses and mirrors to collect starlight and

light reflected off of planets

Two main types:⚫REFRACTING – simple refractors uses two lenses.

One lens collects the light, and the other magnifies the image.

⚫REFLECTING – uses a large curved mirror to gather and focus the light. Another lens magnifies the image.

REFRACTING – SIMPLE OPTICAL TELESCOPE

REFLECTING– ADVANCED OPTICAL TELESCOPE

OPTICAL TELESCOPES

Keck TelescopesSummit view of the twin Keck telescopes, located at 13,600 atop a dormant volcano in Hawaii.

KEPLER’S LAWS1. THE LAW OF ELLIPSESThe Path of the planets about the sun is elliptical in shape, with the center of the sun being located at one focus.

2. THE LAW OF EQUAL AREASAn imaginary line drawn from the center of the sun to the center of each planet will sweep out equal areas in equal intervals of time.

KEPLER’S LAWS

3. THE LAW OF HARMONIESCompares the orbital period and radius of orbit of a planet to those of other planets.

KEPLER’S LAWS

Astrophotography

Classification of Galaxies based on shape!Spiral-

Irregular-

Elliptical-

Galaxies are a system of stars, gases, dust and other matter that orbits a common center of gravity.

Scientists that are searching for new solar systems look for clouds of gas and dust.

All galaxies are made of the same materials.

How do we know other stars have planets?Periodic dimming of stars

Milky Way Galaxy• Our solar system is surrounded by newly formed

stars.

THE WAY WE MOVEROTATION

REVOLUTIONPROCESSION

TILTNUTATION

BARYCENTER

WHAT IS ROTATION?

The turning or spinning of a body on its axis.

EARTH’S ROTATION

The average ROTATION PERIOD of the Earth with respect to the SUN is 24 hours (the mean solar day).

Rotation effects the core.• Earth’s liquid metal outer core spins because of

rotation.• The solid metal inner core does not spin.• This phenomenon creates the magnetosphere• The magnetosphere diverts harmful solar

radiation from space away from Earth’s surface.• The interaction of the charged particles with

Earth’s magnetosphere creates something amazing.

• Auroras boreales

WHAT IS REVOLUTION?The motion of a body along a path around some point in space. This is also called ORBITAL MOTION

EARTH’S REVOLUTION

It is the orbital period of EarthIt is the orbital period of Earth, equal to 365.25636042 mean solar days.

What is Precession?The slight movement of Earth’s axis over 26,000 years.

DIURNAL MOTION OF STARSWe cannot detect earth’s rotation, so it appears to us as if the stars (and Sun and Moon and planets)

are rotating around us: they rise in the east and set in the west, once

a day.This is called DIURNAL MOTION.

TILT OF EARTH ON AXIS

A FEW MORE WAYS TO MOVENUTATION

–the wobbleChange in the angle of the axis (1/2 degree)

BARYCENTERThe point between two objects where they balance each other. Example: The moon always faces theEarth, due to the force of gravity fromboth objects. “Dark Side of the Moon”

LIFE CYCLE OF STARS

The lifespan of stars varies from thousands of years for massive stars to billions for smaller stars. Our Sun, which is of average mass, is predicted to live for about 10 billion years (it is about halfway through).

HERTZSPRUNG - RUSSELL DIAGRAM

TILT OF EARTH ON AXIS

SPECIAL DAYS OF THE YEAR• WINTER SOLSTICE first day of winter, shortest day of the year

• VERNAL EQUINOX first day of spring, equal day and night

• SUMMER SOLSTICE first day of summer, longest day of the year

• AUTUMNAL EQUINOX first day of autumn (fall), equal day and night

Seasons

DEFINITIONOne of the four periods of the year

(spring, summer, autumn, and winter), beginning astronomically at an equinox

or solstice, but geographically at different dates in different climates.

SPRING• Begins on the vernal equinox• Usually occurs on March 21 or 22 in the northern hemisphere

• Tilt neither toward or away from sun• Equal day and Night

SUMMER• Begins on the summer solstice • Usually occurs on June 21 or 22 in the northern hemisphere

• Tilt toward the sun• Longest day of the year

FALL• Begins on the autumnal equinox• Usually occurs on September 22 or 23 in the northern hemisphere

• Tilt neither toward or away from sun• Equal day and night

WINTER• Begins on the winter solstice• Usually occurs on December 21 or 22 in the northern hemisphere

• Tilt away from sun• Shortest day of the year

Land masses predict temperature• Land heats up and cools fast• Water heats up and cools slowly• Water also stores solar energy• The more land in the temperate zone, the

warmer the Earth will be. • What was the weather like during this

time?

WHAT CAUSES SEASONSTILT! Either toward or away from the sun.

•Tilt TOWARD the sun is maximized during Northern Hemisphere summer in late June (the "summer solstice"). ⚫The amount of sunlight reaching the Northern Hemisphere is at a

maximum.

•Tilt AWAY from the sun is maximized during Northern Hemisphere winter in December (the “winter solstice").⚫a minimum of sunlight reaches the Northern Hemisphere.

**The seasons are reversed in the Southern Hemisphere

INTERESTING FACTS• The sun is actually closest to the Earth during Northern Hemisphere winter (not summer).

• Because of this, the amount of sunlight averaged over the whole Earth, is as much as 7% more intense in the winter than the summer.

• Despite this fact, the global-average surface temperature is warmer in Northern Hemisphere summer, due to the much greater expanse of land there, and since land heats to a higher temperature than the ocean does.

LIFE CYCLE OF STARS

The lifespan of stars varies from thousands of years for massive stars to billions for smaller stars. Our Sun, which is of average mass, is predicted to live for about 10 billion years (it is about halfway through).

HERTZSPRUNG - RUSSELL DIAGRAM

Energy from the Sun

Essential Question: Describe the energy required for the sun to transmit electromagnetic radiation across the solar system?

LAYERS OF THE SUN• Interior: core⚫cannot be seen⚫where nuclear fusion occurs

• PHOTOSPHERE ⚫Photo =“light” Sphere = “ball” ⚫visible “surface” of the sun

• Sol has consumed about half its energy!• Atmospheric layers• CHROMOSPHERE – thin layer of hot gases⚫CORONA – “crown” outermost portion, produces the solar

wind⚫Earth’s magnetic field blocks the winds from reaching our surface

PRODUCTION OF ENERGY

• COMBUSTION – burning fossil fuels

• RENEWABLE SOURCES – capture energy from the sun, wind, water to produce electricity

• NUCLEAR REACTIONS – when atomic particles interact to form different particles⚫FUSION ⚫FISSION

FUSION• Done in the interior of the sun• Less massive nuclei combine to form more massive nuclei

• 4 hydrogen atoms fuse into 1 helium atom.• This requires a high tempto fuse. 15,000,000℃ • Outward pressure keepsstars from collapsing

FISSION• Able to do on earth (Nuclear Energy)• More massive nuclei are bombarded by neutrons and split to less massive nuclei

• Emits heat energy

Stars• Large stars burn through fuel quickly and die fast• Small stars burn slowly, but have less radiant

energy.• H-Hydrogen and He-Helium are the major

elements found in stars.

ENERGY FLOWEnergy is transferred by ELECTROMAGNETIC RADIATIONThis includes all energy types that travel as waves from X-rays to visible light to microwaves and radio wavesSolar energy (0.023%) is used by plants through photosynthesis to make chemical energy (sugar).Light is required for life.

FORMS OF ENERGY PRODUCED

LIGHT ⚫Acts like a wave and particle⚫Photons are a stream of particles that push on matter⚫This push is what causes a comet’s tail

HEAT⚫The sun is extremely hot (15 million K at core)⚫Waves of heat are ejected into space at all angles

LIFE CYCLE OF STARS

The lifespan of stars varies from thousands of years for massive stars to billions for smaller stars. Our Sun, which is of average mass, is predicted to live for about 10 billion years (it is about halfway through).

HERTZSPRUNG - RUSSELL DIAGRAM