The second largest planet in the solar system is:

Saturn is the second largest planet in the solar system after Jupiter. Its equatorial diameter is about 1,20,500 km, nearly nine and a half times that of the Earth.

Order of planets by size (diameter):

Jupiter, Saturn, Uranus, Neptune, Earth, Venus, Mars and Mercury.

Key facts about Saturn:

• It is the sixth planet from the Sun, at an average distance of about 1.4 billion km.
• It is a gas giant, made mostly of hydrogen and helium.
• It takes about 29.5 Earth years to complete one revolution around the Sun.
• A day on Saturn lasts about 10 hours and 33 minutes.
• It is the least dense planet; its average density is less than that of water, so in theory it would float in a large enough ocean.
• Its strong winds can reach about 1,800 km per hour near the equator.

Saturn's rings:

• Saturn has the most spectacular ring system in the solar system.
• The rings are made of countless pieces of ice and rock, ranging from tiny grains to boulders.
• The main rings stretch out to about 2,80,000 km from the planet but are generally only about 10 metres to 1 km thick.
• The rings are named alphabetically in the order of their discovery, such as the A, B and C rings.

Moons:

Saturn has the largest number of known moons of any planet. In 2025, astronomers announced dozens of new discoveries, taking its total well above 250.

Exploration:

• Pioneer 11 (1979) was the first spacecraft to fly past Saturn.
• Voyager 1 and Voyager 2 flew past it in 1980 and 1981.
• The Cassini spacecraft orbited Saturn from 2004 to 2017 and ended its mission by diving into the planet's atmosphere.

In mythology:

Saturn is named after the Roman god of agriculture and wealth. The day Saturday is named after it.

Why not the other options?

• ✗Uranus is the third largest and Neptune the fourth largest planet.
• ✗Earth is the largest of the rocky planets but only the fifth largest planet overall.