Solar Systems

The Solar System is a group of celestial bodies bound by the gravity of the Sun, which lies at its center.
It includes 8 planets, moons, asteroids, comets, and dwarf planets.
Understanding the solar system helps in geography, satellite launches, and climate studies — all relevant for BPSC, especially with ISRO’s increasing satellite coverage over Bihar.

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Members of the Solar System

1. The Sun

• A medium-sized yellow star
• Composed of Hydrogen and Helium
• Source of light and heat energy for all planets
• Diameter ≈ 13 lakh km
• Energy by nuclear fusion (H → He)

📝 PYQ (BPSC Teacher): Which process produces solar energy? → Nuclear fusion

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2. Planets

• Total: 8 planets
• Orbits the Sun in elliptical paths
• Classification:
  • Inner (terrestrial): Mercury, Venus, Earth, Mars
  • Outer (gas giants): Jupiter, Saturn, Uranus, Neptune
• Mnemonic: My Very Educated Mother Just Served Us Noodles

📝 PYQ (BPSC): Which is the largest planet? → Jupiter
📝 Expected MCQ: Hottest planet in the solar system? → Venus

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3. Dwarf Planets

• E.g., Pluto, Eris, Ceres, Makemake, Haumea
• Pluto was reclassified in 2006 by IAU
• Do not clear their orbit → reason for demotion

📝 Expected MCQ: Which celestial body was removed from planet status in 2006? → Pluto

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4. Satellites (Moons)

• Natural objects that revolve around planets
• Earth’s moon:
  • Only natural satellite
  • Distance: ~3.84 lakh km
  • Causes tides, eclipses, regulates Earth's rotation

📝 PYQ (BPSC 66th): Distance between Earth and Moon? → ~3.84 lakh km
📝 Expected MCQ: Moon causes which phenomenon? → Tides

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5. Asteroids

• Rocky objects between Mars and Jupiter
• Form the Asteroid Belt
• Also called Minor Planets
• Example: Ceres (also a dwarf planet)

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6. Comets

• Made of ice, dust, and gases
• Visible when near Sun → form tail
• Orbit is highly elliptical
• Famous comet: Halley's Comet (appears every 76 years)

📝 Expected MCQ: Halley’s Comet returns after how many years? → 76 years

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7. Meteors & Meteorites

• Meteor: Shooting star seen when a meteoroid burns in atmosphere
• Meteorite: When it reaches Earth’s surface
• Can create craters (e.g., Lonar Lake, Maharashtra)

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Bihar-Specific Applications

• ISRO satellite coverage: INSAT, CartoSat over Bihar → help in flood monitoring, agriculture, weather forecasting
• Solar radiation monitoring: BREDA uses sun-tracking sensors
• PM-Kusum Scheme: Promotes solar-based irrigation using solar energy
• Science exhibitions and planetarium in Patna help in public education

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PYQs + Expected MCQs

📝 PYQ (BPSC 66th): Distance between Earth and Moon? → ~3.84 lakh km
📝 PYQ: Source of solar energy? → Nuclear fusion
📝 Expected MCQ: Hottest planet in the solar system? → Venus
📝 Expected MCQ: Planet with rings? → Saturn
📝 Expected MCQ: Which planet rotates on its side? → Uranus
📝 Expected MCQ: Where is the asteroid belt located? → Between Mars and Jupiter
📝 Expected MCQ: Halley's comet appears after how many years? → 76 years
📝 Expected MCQ: Largest planet in the Solar System? → Jupiter

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Quick Revision Points

• Sun = nuclear fusion, center of solar system
• 8 planets: MVEMJSUN
• Venus: Hottest, retrograde rotation
• Earth: Life + Water + Moon
• Jupiter: Largest
• Saturn: Rings
• Asteroid belt: Mars–Jupiter
• Comets: Ice/dust + elliptical orbit
• Dwarf planets: Pluto, Eris, Ceres
• Meteors: Burn → shooting stars
• Moon: Tides, eclipses, 3.84 lakh km

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Sources Used

• NCERT Class 6–8 Science
• Lucent GK – Astronomy Section
• Drishti Quick Book – Science
• Ghatna Chakra BPSC PYQs
• ISRO.gov.in updates
• Bihar Renewable Energy Development Agency (BREDA)
• EduTeria MCQs