The Universe and Solar System are among the most important topics in the Static General Knowledge section of the AFCAT examination. Questions are generally factual and concept-based, covering planets, stars, galaxies, satellites, and space missions. A good understanding of this topic can help candidates score easily in the GK section.
AFCAT 2 2026 Exam Static GK- Universe & Solar Systems
Universe
The Universe includes everything that exists — stars, planets, galaxies, matter, energy, and space itself. Scientists believe the Universe originated nearly 13.8 billion years ago through the Big Bang Theory.
Important Facts About the Universe
- Big Bang Theory explains the origin of the Universe.
- The study of the Universe is called Cosmology.
- The Universe is continuously expanding.
- The nearest galaxy to the Milky Way is the Andromeda Galaxy.
- The distance travelled by light in one year is called a Light Year.
- One Light Year is approximately 9.46 trillion kilometers.
Galaxies
A galaxy is a huge collection of stars, gas, dust, and dark matter held together by gravity.
Types of Galaxies
- Spiral Galaxy
- Elliptical Galaxy
- Irregular Galaxy
Milky Way Galaxy
- Our Solar System is located in the Milky Way Galaxy.
- It is a spiral-shaped galaxy.
- It contains billions of stars.
Solar System
The Solar System consists of the Sun and all celestial bodies revolving around it due to gravitational force.
Formation of Solar System
- Formed nearly 4.6 billion years ago.
- Developed from a cloud of gas and dust called the Solar Nebula.
The Sun
The Sun is the center of the Solar System and the main source of heat and light.
Important Facts About the Sun
- It is a star made mainly of hydrogen and helium.
- Energy is produced through nuclear fusion.
- Surface temperature is around 5500°C.
- Core temperature is around 15 million°C.
- Average distance from Earth: 149.6 million km.
- This distance is called 1 Astronomical Unit (AU).
Planets of the Solar System
There are 8 planets in the Solar System.
| Planet | Important Fact |
|---|---|
| Mercury | Closest planet to the Sun |
| Venus | Hottest planet |
| Earth | Only known planet with life |
| Mars | Known as the Red Planet |
| Jupiter | Largest planet |
| Saturn | Famous for rings |
| Uranus | Rotates on its side |
| Neptune | Farthest planet from the Sun |
Classification of Planets
Inner Planets (Terrestrial Planets)
- Mercury
- Venus
- Earth
- Mars
Features:
- Rocky surface
- Smaller in size
- Closer to the Sun
Outer Planets (Gas Giants)
- Jupiter
- Saturn
- Uranus
- Neptune
Features:
- Large in size
- Gaseous composition
- Have many moons
Dwarf Planets
In 2006, Pluto was reclassified as a dwarf planet by the International Astronomical Union (IAU).
Major Dwarf Planets
- Pluto
- Ceres
- Eris
- Haumea
- Makemake
Natural Satellites
A natural satellite is a celestial body that revolves around a planet.
Important Facts
- Earth has one natural satellite — the Moon.
- Ganymede is the largest moon in the Solar System.
- Titan is Saturn’s largest moon.
- Mars has two moons:
- Phobos
- Deimos
Asteroids, Comets and Meteors
Asteroids
- Rocky objects revolving around the Sun.
- Mostly found between Mars and Jupiter in the Asteroid Belt.
Comets
- Made of ice, dust, and gases.
- Develop a bright tail near the Sun.
- Example: Halley’s Comet.
Meteoroids, Meteors and Meteorites
- Meteoroids are small rocky particles in space.
- When they enter Earth’s atmosphere and burn, they are called Meteors.
- If they reach Earth’s surface, they are called Meteorites.
Important Astronomical Terms
| Term | Meaning |
| Light Year | Distance travelled by light in one year |
| AU | Distance between Earth and Sun |
| Black Hole | Region with extremely strong gravity |
| Supernova | Explosion of a massive star |
| Nebula | Cloud of gas and dust in space |
Important Space Missions
Indian Space Missions
Chandrayaan Missions
- Lunar exploration missions by ISRO.
Chandrayaan-3
- Successful soft landing near Moon’s south pole.
Aditya-L1
- India’s first solar mission.
Mangalyaan
- India’s Mars Orbiter Mission.
International Missions
Voyager 1 & 2
- Exploring interstellar space.
Parker Solar Probe
- Studying the Sun’s corona.
Important AFCAT One-Liners
- Largest planet — Jupiter
- Smallest planet — Mercury
- Brightest planet — Venus
- Red Planet — Mars
- Planet with rings — Saturn
- Earth’s twin — Venus
- Blue Planet — Earth
- Largest moon — Ganymede
- Farthest planet — Neptune
- Nearest star to Earth — Sun
Preparation Tips for AFCAT 2 2026
- Learn planetary facts thoroughly.
- Revise space missions regularly.
- Practice one-liner GK questions daily.
- Focus on ISRO missions and recent developments.
- Prepare comparative facts of planets and satellites.
Conclusion
Universe and Solar System is a scoring topic in AFCAT Static GK. Most questions are direct and factual. Regular revision of planets, galaxies, satellites, and important space missions can help candidates secure easy marks in the examination. Candidates should also stay updated with recent ISRO and international space missions for better preparation.
