Solar System
Celestial Bodies Comparison
Body Type
Description
Examples/Features
Luminous
Self-glowing
Stars, Sun
Non-Luminous
Not self-glowing, but reflects light from other sources
Moon, Planets
Asteroids
Small, rocky objects orbiting the Sun
Asteroid Belt (between Mars & Jupiter)
Meteoroids/Meteors
Enters Earth's atmosphere and burns up in Mesosphere
Shooting stars
Comets
Small icy dirt balls orbiting the Sun, burn upon reaching Sun
Halley's Comet
Constellations
Constellation Name
Hydra
Ursa Major
Orion
Sirius
Feature
Largest
Saptarishi (Seven Sages)
Rigel - Brightest star

Dog Star - Brightest in night sky
Sun and Moon
Feature
Sun
Moon
Distance
150 million km from Earth (1.5 × 10^8 km)मी)
384,000 km from Earth
Light Travel Time
8 min 30 sec
1.26 sec
Composition
H (73%), He (25%), other metals; 99% solar system mass
Non-luminous; Radius: 1.74 × 10^6 km
Temperature
Surface: 5800 K (5600°C); Center: 15.7 million K
-
Other
Closest star to Sun: Proxima Centauri; Outer layer: Corona
Rotation = Revolution = 27.3 days; Only one side visible; Earth's gravity = 6 × Moon's
Origin of Solar System
Nebular Theory
Stage Description
1755 Proposed by Immanuel Kant
1796 Modified by Laplace
Process Gas-dust cloud (Nebula) contracts → Sun forms at center → Remaining material forms planets/rings
Planets (Size Order: Jupiter > Saturn > Uranus > Neptune > Earth > Venus > Mars > Mercury)
Terrestrial Planets (Inner)
Planet
Features
Mercury
Closest to Sun, smallest (Diameter: 4900 km), revolution: 88 days, no satellites, fastest orbital speed
Venus
Hottest, brightest (Evening/Morning Star), Earth's twin (similar mass/size), clockwise rotation, no satellites
Earth
Only life-supporting, Blue Planet (70% water), densest, 1 satellite (Moon)
Mars
Red Planet (FeO), 2nd smallest, 2 satellites (Phobos & Deimos), Olympus Mons (largest volcano & tallest mountain)
Jovian Planets (Outer)
Planet
Features
Jupiter
Largest, shortest rotation (10 hours), H/He atmosphere, 3rd brightest (after Moon/Venus), satellites: Ganymede (largest overall), Io, Europa, Callisto (all by Galileo), faint ring
Saturn
2nd largest, least dense, bright concentric rings (rocks/gas/dust/ice), largest satellite: Titan; Discoveries: Huygens (1655 - rings), Cassini (1675 - divisions)
Uranus
Green (Methane), Ice Giant, coldest, 98° axial tilt (rolling/lopsided), clockwise like Venus, discovered: William Herschel (1781); Atmosphere: H/He, water, ammonia, methane
Neptune
Farthest, Ice Giant, bluish (methane), H/He atmosphere, 14 satellites (Triton famous), discovered: Johann Galle & Urbain Le Verrier (1846, mathematical predictions)
Earth
Age Determination Methods
Method
-
Uranium-Lead
-
Potassium-Argon
-
Rubidium-Strontium
-
Radiocarbon (C-14)
-
Chlorine-36
-
Inventor
Type
Oldest rocks
General rocks
General
Recent rocks/organic
Special
Ernst Rutherford (1905)
Use
Radioactive
Radioactive
Radioactive
Radioactive
Radioactive
-
Shape and Motion
Feature
Description
Shape
Radius
Rotation
Revolution
Perihelion/Aphelion
Perigee/Apogee
Inclination/Divisions
Geoid/Oblate Spheroid (flattened at poles)
भूEquatorial: 6378 km; Polar: 6357 km; Mean: 6371 km
23 hr 56 min 4 sec (west to east); max speed at equator, min at poles
365 days 6 hr 9 min 9 sec; orbital speed: 29.8 km/sec (elliptical orbit)
Jan 3 (1.475 × 10^8 km); Jul 4 (1.525 × 10^8 km)
Moon closest/farthest from Earth
Axial: 23.5°; Orbital: 66.5°/Equator (horizontal, N/S hemispheres); Prime Meridian (vertical, E/W hemispheres)
Latitude and Longitude
Description
Type
Latitude
Imaginary horizontal E-W lines, angular distance from equator

Distance/Number
1° = 111 km; Total: 181; Largest: Equator; Smallest: Poles (N/S)
Longitude
Imaginary vertical N-S lines, angular distance from Prime Meridian
Equator: 111.32 km max; Poles: 0 km min; Total: 360; All divide Earth into 2 equal parts; Prime: 0° (Greenwich, London; through 8 countries: UK, France, Spain, Algeria, Mali, Burkina Faso, Togo, Ghana); International Date Line: 180° (zig-zag)
Solstice & Equinox
Type
Summer Solstice
Winter Solstice
Vernal Equinox
Autumnal Equinox
Date
Jun 21
Dec 22
Mar 21
Sep 23
Description
Continuous Sun rays on North Pole for 6 months; longest day, overhead rays on Tropic of Cancer (23.5°N)
Continuous Sun rays on South Pole for 6 months; shortest day, overhead rays on Tropic of Capricorn (23.5°S)
Direct rays on Equator; equal day/night
Direct rays on Equator; equal day/night
Eclipses
Type
विवरण
Solar Eclipse
Moon blocks Sun's light/ Total (full shadow), Annular (ring), Partial; Diagrams show umbra/penumbra shadows
Lunar Eclipse
Earth blocks Sun's light on Moon /Super Moon (during eclipse + perigee) appears bigger; Light refraction in atmosphere



Earth's Interior
Layers
Layer
Composition
Crust
SiAl (Continental: granitic, lighter, land part 30 km; Oceanic: basaltic, denser, water part 5 km)
Mantle
SiMa (Silica & Magnesium)
Thickness
State/Sub-divisions
5-70 km
Solid
2900 km
Top: solid (Upper Mantle); Lower: semi-molten (Asthenosphere)Top: solid (Upper Mantle); Lower: semi-molten (Asthenosphere)
Core
NiFe (Nickel & Iron)
Inner: 2200 km; Outer: 1300 km
Inner: solid; Outer: liquid (shows magnetic properties)
Discontinuities
Name
Location
Conrad/Moho
Outer & Inner Crust / Crust & Upper Mantle
Gutenberg
Mantle & Outer Core

Lehmann
Outer & Inner Core
Earthquake Measurement Scales
Scale
Measures
Range
Richter
Magnitude
0-10 (limitless)
Mercalli
Intensity
1-12
Plate Boundary Types
Boundary Type
Effect
Volcanism/Earthquakes
Divergent (Spreading)
New lithosphere created (oceanic)
Yes (ridge)
Convergent (Subduction)
Lithosphere destroyed (oceanic)
Yes (trench, volcanoes)
Transform (Lateral Sliding)
No creation/destruction
Yes (earthquakes within crust)
Rocks
Types
Type
Formation
Sub-types
Examples
Igneous
Magma cooling
Intrusive (inside); Extrusive (outside)
Granite, Basalt
Sedimentary
Sediment deposition/compaction; fossils
Mechanical, Organic, Chemical
Sandstone, Limestone, Coal
Metamorphic
Pressure/heat recrystallization
Thermal (heat); Dynamic (pressure)
Marble, Slate
Rock Cycle
Stage
Process

Igneous → Sedimentary
Weathering + transport + deposition
Sedimentary → Metamorphic
Metamorphic → Igneous
Pressure/heat
Melting + cooling

Volcanoes
Type
Lava Characteristic
Cinder
-
Composite
Stickiest
Shield
Least sticky
Caldera
Most explosive, collapses
Example
-
Fujiyama
Mauna Loa
Yellowstone
Continents and Oceans
Continents (Area Order)
Rank
1
2
3
4
5
6
7
Continent
Asia
Africa
North America
South America
Antarctica
Europe
Australia
Oceans (Area Order)
Rank
1
2
3
4
5
Ocean
Pacific
Atlantic
Indian
Southern (Antarctic)
Arctic
Corals
Feature
Symbiotic
Favorable Conditions
Largest
Bleaching
Description
Zooxanthellae algae
Salty water, sunlight, clear water, 30-35°C
Great Barrier Reef (Australia)
Expulsion of algae due to hot water, turns white
Continental Drift
Theory
Causes
Evidence
Alfred Wegener (1912)
Tidal/polar forces, convection cells
Jigsaw fit, fossils, placer deposits
Atmosphere
Layers
Layer
Altitude
Temperature Change
Feature
Troposphere
Poles: 8 km; Equator: 18 km
Decreases (6.5°C/km)
Weather events, harmful ozone
Stratosphere
Above
Increases
Ozone layer (30-35 km, UV protection); Jet planes; Ozone Day: Sep 16, 1987
Thermosphere
-
Decreases
Coldest, meteor burn-up
मध्यमंडल
-
Increases
Ionosphere (reflects radio waves); Karman Line (100 km)
Gas Composition
Gas
Nitrogen
Oxygen
Argon
CO2
Percentage
78%
21%
0.9%
0.036%


Others (He etc.)
Rest



Heating Mechanisms
Process
Conduction
Convection
Radiation
Description
Vertical heat from Earth surface
Vertical transfer
Horizontal transfer (e.g., Loo wind)
Water
Distribution
Type
% of Total Water
Saline
Fresh
Glaciers/Ice
Groundwater
97.2%
2.8%
2%
0.68%
% of Fresh Water
-
100%
68.7%
30.1%
Lakes
Atmosphere/Rivers
0.4%
0.9%
Rest
Rest
Water Cycle
Stage
Evaporation
Condensation
Precipitation
Description
Liquid → Gas
Gas → Liquid
Rain/snow/hail
Humidity
Type
Absolute
Relative
Dew Point
Description
Actual water vapor amount
% of saturation capacity
Saturation temperature
Condensation Forms
Form
Dew
Fog
Mist
Description
Small droplets on surface
Larger particles
Small particles
Frost
Ice crystals on hygroscopic nuclei
Clouds
Level
Low
Low
Middle
High
Type
Feature
Nimbus
Rain-bearing, dark, opaque
Stratus
Layered
Cumulus
Cotton-like, 4000-7000 m, no rain
Cirrus
Feathery, no rain
Rainfall Types
Type
Convectional
Orographic
Cyclonic
Cause
Surface heating
Mountains
Cyclones
Hail
Snow/Sleet
Large size
Frozen small drops
Geomorphology
Endogenic/Exogenic Forces
Force
Endogenic
Exogenic
Type
Internal (radioactive/primordial heat)
Land building (orogeny/continent building)
External (solar energy)
Erosion/weathering (river/wind/sea/groundwater)
Effect
Weathering Types
Type
Chemical
Physical
Biological
Description
Decomposition
Mechanical without chemical change
By organisms/plants
Mass Movement
Type
Creep
Solifluction
Landslide/Avalanche
Description
Slow slope movement
Slow progressive movement
Gravity-induced
Erosional/Depositional Landforms
Agent
River
Glacier
Groundwater
Sea Waves
Erosional
Depositional
V-shaped valley, waterfalls, meanders
Delta, flood plains
Cirque, arete, U-shaped valley
Moraine, drumlin
Sinkhole, uvala
Stalactite/stalagmite
Caves, arches
Beach, bar
Wind
Sand dunes (barchan)
Pediment, mushroom rock
