How many planets are in the solar system

There are 8 planets in the Solar System. They are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Until 2006, Pluto was also included in the list of planets, but its status was changed to “dwarf planet.”

Ancient Times and Early Observations

Since ancient times, people have observed the sky and identified luminous objects among the stars that moved differently from the others. Thus, five planets were known: Mercury, Venus, Mars, Jupiter, and Saturn. They were observed by the ancient Egyptians, Babylonians, and Greeks.

Discovery of New Planets

With the development of telescopes, scientists were able to see more celestial bodies. In 1781, William Herschel discovered Uranus—the first planet discovered during the era of telescopic observations. Then, in 1846, Neptune was discovered based on mathematical calculations.

How Planets Lose Their Status

The Fate of Pluto

Pluto was discovered in 1930 and was considered the ninth planet until 2006. However, astronomers began to discover many similar objects in the Kuiper Belt. As a result, the International Astronomical Union changed the definition of a planet, and Pluto lost its status, becoming a dwarf planet.

Interesting Facts About the Planets

• Jupiter could have become a star—if it had gained more mass, it could have ignited and become a star.
• Venus has the longest day—its day lasts longer than its year.
• On Uranus, summer lasts for 42 years—due to the planet’s extreme axial tilt, one part of the planet can stay illuminated for decades.
• Pluto is smaller than the Moon—its diameter is only 2,376 km, making it smaller than Earth’s satellite.

Today, there are 8 planets in the Solar System, but our cosmic history continues to unfold. Perhaps, in the future, astronomers will reconsider the classification of celestial bodies or discover something new!