Pratik Geography Project

8/6/2019 Pratik Geography Project

1/27

IX AIX AGEGRAPHYGEGRAPHY PROJECTPROJECT

PratikPratik JaywantJaywant AhireAhire


2/27

Day and NightDay and Night

Earth MotionEarth Motion


3/27

Early history of astronomyEarly history of astronomy

Birth of modern astronomyBirth of modern astronomy

1500s and 1600s1500s and 1600s

Five noted scientistsFive noted scientists

Nicolaus CopernicusNicolaus Copernicus (1473(1473--1543)1543)

Concluded Earth was a planetConcluded Earth was a planet

Constructed a model of the solar system that putConstructed a model of the solar system that putthe Sun at the center, but he used circular orbitsthe Sun at the center, but he used circular orbitsfor the planetsfor the planets

Ushered out old astronomyUshered out old astronomy


4/27




Tycho BraheTycho Brahe (1546(1546--1601)1601)

Precise observerPrecise observer

Tried to findTried to find stellar parallaxstellar parallax the apparent shift inthe apparent shift ina star's position due to the revolution of Eartha star's position due to the revolution of Earth

Did not believe in the Copernican system becauseDid not believe in the Copernican system becausehe was unable to observe stellar parallaxhe was unable to observe stellar parallax


5/27




Johannes KeplerJohannes Kepler (1571(1571--1630)1630)

Ushered in new astronomyUshered in new astronomy

Planets revolve around the SunPlanets revolve around the Sun

Three laws of planetary motionThree laws of planetary motion

Orbits of the planets are ellipticalOrbits of the planets are elliptical

Planets revolve around the Sun at varyingPlanets revolve around the Sun at varyingspeedspeed


6/27




Sir Isaac NewtonSir Isaac Newton (1643(1643--1727)1727) Law of universal gravitationLaw of universal gravitation

Proved that the force of gravity, combined withProved that the force of gravity, combined withthe tendency of a planet to remain in straightthe tendency of a planet to remain in straight--lineline

motion, results in the elliptical orbits discoveredmotion, results in the elliptical orbits discoveredby Keplerby Kepler


7/27




Johannes KeplerJohannes Kepler (1571(1571--1630)1630)

Three laws of planetary motionThree laws of planetary motion

There is a proportional relation between aThere is a proportional relation between aplanet's orbital period and its distance to theplanet's orbital period and its distance to the

Sun (measured inSun (measured in astronomical unitsastronomical units (AUs)(AUs) oneoneAUAU averages about 150 millionaverages about 150 millionkilometers, or 93 million miles)kilometers, or 93 million miles)


8/27


Birth of modern astronomyBirth of modern astronomy Five noted scientistsFive noted scientists

Galileo GalileiGalileo Galilei (1564(1564--1642)1642) Supported Copernican theorySupported Copernican theory

Used experimental dataUsed experimental data

Constructed an astronomical telescope in 1609Constructed an astronomical telescope in 1609

Four large moons of JupiterFour large moons of Jupiter Planets appeared as disksPlanets appeared as disks

Phases of VenusPhases of Venus

Features on the MoonFeatures on the Moon

SunspotsSunspots


9/27

Keplers law ofequal areasKeplers law ofequal areas


10/27

Earths Physical DataEarths Physical Data

In the past, some people thought that the Sun,In the past, some people thought that the Sun,

the Moon, and other objects in space movedthe Moon, and other objects in space movedaround Earth each day.around Earth each day.

Now it is known that some of the motions ofNow it is known that some of the motions ofthese objects, as observed from Earth, are reallythese objects, as observed from Earth, are really

caused by Earths movementscaused by Earths movements


11/27

Earths Motion and SeasonsEarths Motion and Seasons


12/27

Motions of EarthMotions of Earth

Earths geographic poles are located at the northEarths geographic poles are located at the north

and south ends of Earths axis.and south ends of Earths axis.


13/27


Earths axis is the imaginary line drawn from theEarths axis is the imaginary line drawn from the

north geographic pole through Earth to thenorth geographic pole through Earth to thesouth geographic pole.south geographic pole.


14/27


The spinning of Earth on its axis, calledThe spinning of Earth on its axis, calledrotationrotation, causes you to experience day and, causes you to experience day andnight.night.


15/27

Earths OrbitEarths Orbit

As it rotates on its axis each day, Earth alsoAs it rotates on its axis each day, Earth also

moves along a path around the Sun. Thismoves along a path around the Sun. Thismotion of Earth around the Sun is calledmotion of Earth around the Sun is called

revolution.revolution.


16/27

Earths TiltEarths Tilt

Earths axis forms a 23.5Earths axis forms a 23.5--degree angle with a linedegree angle with a line

perpendicular to the plane of its orbit aroundperpendicular to the plane of its orbit aroundthe Sun.the Sun.

Because of this, there are more daylight hoursBecause of this, there are more daylight hoursfor the hemisphere tilted toward the Sun.for the hemisphere tilted toward the Sun.


17/27


Sunlight strikes the hemisphere tilted toward theSunlight strikes the hemisphere tilted toward the

Sun at a higher angle, that is, closer to 90Sun at a higher angle, that is, closer to 90degrees.degrees.


18/27


Sunlight strikes the hemisphere tilted away fromSunlight strikes the hemisphere tilted away from

the Sun at a lower angle. This lessens solarthe Sun at a lower angle. This lessens solarradiation and brings winter.radiation and brings winter.


19/27

ConstellationsConstellations

Configuration of stars named in honor ofConfiguration of stars named in honor ofmythological characters or great heroesmythological characters or great heroes

Today 88 constellations are recognizedToday 88 constellations are recognized Constellations divide the sky into units, likeConstellations divide the sky into units, like

state boundaries in the United Statesstate boundaries in the United States

The brightest stars in a constellation areThe brightest stars in a constellation areidentified in order of their brightness by theidentified in order of their brightness by theletters of the Greek alphabetletters of the Greek alphabet alpha, beta,alpha, beta,and so onand so on


20/27

Earth motionsEarth motions

Two primary motionsTwo primary motions

RotationRotation

Turning, or spinning, of a body on its axisTurning, or spinning, of a body on its axis


21/27

Earth motionsEarth motions

Two primary motionsTwo primary motions

RevolutionRevolution

The motion of a body, such as a planet or moon,The motion of a body, such as a planet or moon,along a path around some point in spacealong a path around some point in space

Earth's orbit is ellipticalEarth's orbit is elliptical

Earth is closest to the Sun (Earth is closest to the Sun (perihelionperihelion) in January) in January

The plane of theThe plane of the eclipticecliptic is an imaginary plane thatis an imaginary plane thatconnects Earth's orbit with the celestial sphereconnects Earth's orbit with the celestial sphere


22/27

Motions of theEarthMotions of theEarth--Moon systemMoon system

Lunar motionsLunar motions

EarthEarth--MoonMoon

Moon's period of rotation about its axis and itsMoon's period of rotation about its axis and itsrevolution around Earth are the same, 27 1/3revolution around Earth are the same, 27 1/3daysdays

Causes the same lunar hemisphere to always faceCauses the same lunar hemisphere to always faceEarthEarth


23/27


EclipsesEclipses

Simply shadow effects that were first understoodSimply shadow effects that were first understood

by the early Greeksby the early Greeks Two types of eclipsesTwo types of eclipses

Solar eclipseSolar eclipse

Moon moves in a line directly between Earth andMoon moves in a line directly between Earth and

the Sunthe Sun

Can only occur during the newCan only occur during the new--Moon phaseMoon phase


24/27

SolareclipseSolareclipse


25/27


EclipsesEclipses

Two types of eclipsesTwo types of eclipses

Lunar eclipseLunar eclipse

Moon moves within the shadow of EarthMoon moves within the shadow of Earth

Only occurs during the fullOnly occurs during the full--Moon phaseMoon phase

For any eclipse to take place, the Moon must be inFor any eclipse to take place, the Moon must be in

the plane of the ecliptic at the time of newthe plane of the ecliptic at the time of new-- or fullor full--MoonMoon


26/27


EclipsesEclipses

Two types of eclipsesTwo types of eclipses

Lunar eclipseLunar eclipse

Because the Moon's orbit is inclined about 5Because the Moon's orbit is inclined about 5degrees to the plane of the ecliptic, during most ofdegrees to the plane of the ecliptic, during most ofthe times of newthe times of new-- and fulland full--Moon the Moon isMoon the Moon is

above or below the plane, and no eclipse canabove or below the plane, and no eclipse canoccuroccur

The usual number of eclipses is four per yearThe usual number of eclipses is four per year


27/27

LunareclipseLunareclipse

Documents

Pratik Geography Project