Earth Solar System
Earth solar system consists of :
• The Sun
• The Planets
• Dwarf Planets & countless fragments of left – overs called asteroids, meteors, comets & satellites of the planets (called small solar system Bodies).
Solar System Some Facts
• Biggest Planet : Jupiter
• Smallest Planet : Mercury
• Nearest Planet to Sun : Mercury
• Farthest Planet from Sun : Neptune
• Nearest Planet to Earth : Venus
• Brightest Planet : Venus
• Brightest star after Sun : Sirius
• Planet with maximum satellites: Jupiter
• Coldest Planet : Neptune
• Hottest Planet : Venus
• Heaviest Planet : Jupiter
• Red Planet : Mars
• Biggest Satellite : Gannymede
• Smallest Satellite : Deimos
• Blue Planet: Earth
• Morning/Evening Star : Venus
• Earth’s Twin : Venus
• Green Planet : Neptune
• Planet with a big red spot : Jupiter
• Lord of the Heavens : Jupiter
• Greatest Diurnal Temperature: Mercury
Earth Latitude & Longitude
• Imaginary lines drawn parallel to the equator. Measured as an angle whose apex is at the centre of the earth.
• The equator represents 0° latitude, while the North Pole is 90° N & the South Pole 90° S
• 23½° N represents Tropic of Cancer while 23½° S represents Tropic of Capricorn.
• 66½° N represents Arctic Circle while 66½° S represents Antarctic Circle.
• There are total 181 latitudes including the equator. Each parallel of latitude is a circle, but they are not equal.
• The circle becomes smaller toward`s the poles. Equator is the ‘Greatest Circle’ that can be drawn on the earth’s surface.
• The distance between any two parallels of latitude is always equal.
• 1 degree lat. = 111km
• It is the angular distance measured from die centre of the earth. On the globe the lines of longitude are drawn as a series of semicircles that extend from the North Pole to the South Pole through the equator. They are also called meridians.
• The distance between any two meridians is not equal.
• At the equator, 1 degree = 111 km. At 30°N or S, it is 96.5 km. It goes on decreasing this way until it is zero at the poles.
• There are 360 meridians of longitude. The prime meridian is a longitude of 00, passing through the Royal Observatory at Greenwich near London.
• This meridian is taken by geographers to divide the earth into the eastern & the western hemispheres.
• Each meridian of longitude is a semi-circle. 180° meridian (International Date Line) lies exactly opposite to 0° meridian. Such points are called Antipodal Points.
• The earth is divided into 24 longitudinal zones, each being 15° or 1 hour apart in time (4 minutes / degree).
Longitude & Time
• Places that are on the same meridian have the same local (sun) time. Since the earth makes one complete revolution of 360° in 24 hours, it passes through 15° in one hour or 1°
in 4 minutes.
• The earth rotates from west to east, hence places east of Greenwich see the sun earlier & gain time whereas places west of Greenwich see the sun later & lose time.
• India, whose longitudinal extent is approx. 30°, has adopted only one time zone, selecting the 82.5°E for the standard time which is 5 hours & 30 minutes ahead of GMT
(Greenwich Mean Time).
International Date Line
• It is the 180° meridian running over the Pacific Ocean, deviating at Aleutian Islands, Fiji, Samoa & Gilbert Islands. It is a zig-zag line
• Travelers crossing the Date Line from west to east (i.e., from Japan to USA) repeat a day & travelers crossing it from east to west (i.e., from USA to Japan) lose a day.
…to be continued