Planets

Planets are celestial bodies that orbit stars, have sufficient mass for gravity to make them roughly spherical, and have cleared the neighbourhood around their orbit. In our solar system, there are 8 confirmed planets — 4 terrestrial rocky worlds and 4 gas or ice giants.

Scientists have discovered over 5,500 exoplanets orbiting other stars, with potentially billions more awaiting detection. Worlds range from lava-covered hellscapes to frozen oceanic moons that may harbour life.

• Mercury — Smallest planet. Surface temperatures swing from −180°C to 430°C.
• Venus — Hottest planet at 465°C. Dense CO₂ atmosphere with sulphuric acid clouds.
• Earth — Only known harbour of life. Liquid water, magnetic field, oxygen atmosphere.
• Mars — Red iron-oxide surface. Evidence of ancient rivers and possible past life.
• Jupiter — Largest planet. The Great Red Spot is a storm older than 300 years.
• Saturn — Iconic ring system made of ice and rock, 282,000 km wide.
• Uranus — Rotates on its side at 98°. Coldest planetary atmosphere at −224°C.
• Neptune — Strongest recorded winds at 2,100 km/h. 30× farther from Sun than Earth.