Timeline of discovery of Solar System planets and their moons
The solar system is made up of a Sun, eight planets, and all their moons. It's like a big family.
In ancient times, people looked at the night sky and noticed that there were some stars that moved around, like a family. We now know these as the planets in our Solar System.
The first person to suggest that there were planets around the Sun was Nicolaus Copernicus in 1543. He said the planets orbited, or moved around, the Sun instead of the Earth.
In 1609, the Italian astronomer Galileo Galilei used a telescope to look at the night sky. He was the first to observe four of the planets in the solar system: Mercury, Venus, Mars, and Jupiter. He discovered four of Jupiter's moons as well.
In 1781, German astronomer William Herschel used a telescope to discover Uranus. Later, he discovered two more moons around Uranus.
In 1846, the planet Neptune was spotted by astronomer Johann Galle.
In 1930, astrophysicist Clyde Tombaugh discovered the planet Pluto. But in 2006, scientists decided it wasn't a planet. Now, Pluto is called a dwarf-planet.
In the 1990s, astronomers used powerful telescopes to discover many more moons around the planets in the Solar System. They found a total of more than 200 moons, and there are more that are still waiting to be discovered!
In ancient times, people looked at the night sky and noticed that there were some stars that moved around, like a family. We now know these as the planets in our Solar System.
The first person to suggest that there were planets around the Sun was Nicolaus Copernicus in 1543. He said the planets orbited, or moved around, the Sun instead of the Earth.
In 1609, the Italian astronomer Galileo Galilei used a telescope to look at the night sky. He was the first to observe four of the planets in the solar system: Mercury, Venus, Mars, and Jupiter. He discovered four of Jupiter's moons as well.
In 1781, German astronomer William Herschel used a telescope to discover Uranus. Later, he discovered two more moons around Uranus.
In 1846, the planet Neptune was spotted by astronomer Johann Galle.
In 1930, astrophysicist Clyde Tombaugh discovered the planet Pluto. But in 2006, scientists decided it wasn't a planet. Now, Pluto is called a dwarf-planet.
In the 1990s, astronomers used powerful telescopes to discover many more moons around the planets in the Solar System. They found a total of more than 200 moons, and there are more that are still waiting to be discovered!