Geography Chap 1 (Goh Cheng Leong + NCERT)

The Earth and the Universe

Chapter 1

Feeling dimensions of Universe:
--Speed of light =299,792,458 m/sec.
--Light takes = 1.3 seconds = from Moon to earth.
--Light takes = 8 min= from Sun to earth.
--Light takes= 4.3 Years = from other nearest star(Proxima century).

Solar system:
--Formation= condensation of gas + lesser bodies.
--Orbit(all planets)= Elliptical.
--Sun temperature= surface(6,000 °C) + core(20 million °C).
--Sun = size = 3 Lakh X Earth.
--Mercury = closest planet = shortest period of revolution.
--Venus = 2^nd = Earth’s twin= approx same size, mass, density @ Earth.
--Earth= 3^rd = has 1 satellite= moon takes 27 day revolution(Eastward).
--Mars =4^th = dark patches .(Image below ↓)


Asteroid belts (between Mars and Jupitor)

JOVIAN PLANETS (↓):
--Jupitor =5^th =identity à12 Moons+ Circular light and dark bands = temp -130 °C.
(Image below ↓)

--Saturn =6^th =identity à Ring + 9 Moon (Image below ↓):



--Uranus= 7^th = identity à (retrograde motion)rotates in Clockwise (West to East) + tilted so much as it appears rotating horizontally. (Image below ↓)


--Neptune= 8^th =identity à(retrograde motion) rotates in Clockwise (West to East) + rotate Vertical like normal planets.(Image below ↓):


--Pluto:
  >> Not a planet.
International Astronomical Union (IAU) downgraded the status of Pluto to that of a dwarf planet because it did not meet the three criteria:
 three criteria of the IAU for a full-sized planet are:

1. It is in orbit around the Sun. ✓
2. It has sufficient mass to assume hydrostatic equilibrium (a nearly round shape). ✓
3. It has “cleared the neighborhood” around its orbit…Kupier belt (image below) exists X
   
   

FACTs:
--Geoid = equatorial dia > polar dia.
--Dawn + Twilight = longer in temperate zone (then  tropical).
                 >> as temperate receives slaint (refracted light) during sun rise and sun set for longer time(in equator sun rises and sets vertically---less time).

calcultaion on Latitude and Longitude ↓

--Prime meridian= passes “Greenwhich”  in London(UK) = international time.
> time calculation:
         >> 1 °Longitude = 4 Minutes.
         >> 1° towards East = add 4 Minutes.
         >> 1° towards West = subtract 4 Minutes.

--International Date line= 180° Longitude line.
         >> Moving towards East = adds 1 day.
         >> Moving towards West = Subtracts 1 day.
         >>Example = Monday in USA --------- Tuesday in India .

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