Explanation

• Nicolaus Copernicus is called the Father of Modern Astronomy.
• He introduced the heliocentric theory in 1543.
• This theory stated that the Sun is at the center of the solar system.
• His ideas changed the old belief that Earth is the center.

Additional information:

• Galileo Galilei, a later figure, is often called the "father of observational astronomy".

Last verified on 01-06-2026

Explanation

• The Earth’s circumference at the equator is about 40,075 km (24,901 miles).
• Measured through the poles, it is slightly smaller: 40,008 km (24,860 miles).
• The difference is due to the equatorial bulge caused by Earth's rotation.
• Diameter: ~12,756 km (7,926 miles).
• Age of Earth: ~4.453 billion years.

Last verified on 31-03-2026

Explanation

• Sea water contains a high amount of dissolved salts.
• Because of salinity, its freezing point is lower than fresh water.
• Fresh water freezes at 0°C, but saltwater freezes at a lower temperature.

Last verified on 01-06-2026

Explanation

• The largest planet in our solar system is Jupiter.
• 5th planet
• 79 known moons (Maximum number of moons)
• The Great Red Spot is a prominent feature
• Giant planet and the fastest-rotating planet 
• Rotates approximately once every 10 hours.
• Age is about 4.603 billion years.

Additional information

• Mercury is the smallest planet of the solar system.

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Last updated 07-09-2026 by NA

Explanation

• Satellites and the Moon move in an elliptical orbit around Earth.
• Their distance from Earth changes at different points in the orbit.
• The farthest point from Earth is given a special scientific name called apogee.
• The closest point has a different name called perigee.

Last verified on 31-05-2026

Explanation

• Earth moves around the Sun in an elliptical orbit.
• Because of this, the distance between Earth and Sun changes during the year.
• The point where Earth is closest to the Sun is called perihelion.
• This occurs in early January every year.

Last verified on 31-05-2026

Explanation

• A cream separator works on the principle of centrifugal force.
• When milk spins rapidly, heavier and lighter components separate.
• The heavier skimmed milk moves outward.
• The lighter cream stays closer to the center.

Last verified on 31-05-2026

Explanation

• A nuclear reactor uses control rods to regulate the fission chain reaction.
• These rods absorb excess neutrons and prevent the reaction from becoming uncontrollable.
• When the reaction becomes too intense, the rods are inserted deeper into the reactor core.
• Cadmium is commonly used because it is an excellent neutron absorber.

Last verified on 31-05-2026

Explanation

• Cinchona bark contains quinine, which is used to treat malaria.
• Quinine is also used in tonic water.
• It belongs to the family Rubiaceae.
• Cinchona is also called the “fever tree”.

Last verified on 31-05-2026

Explanation

• Milk, butter, and ghee are rich in fat-soluble vitamins, especially A and D.
• These vitamins help in vision, bone strength, and calcium absorption.
• They are considered energy-giving and body-building foods.

Last verified on 30-05-2026