By Alexander Merz · Updated on · Details checked on 11 October 2026
Quick answer: Our solar system has 8 planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. On top of that there are 5 recognized dwarf planets – and more than 6,400 confirmed exoplanets orbiting other stars.
Eight planets – since 2006
Until 2006, kids in school learned about nine planets. Then the International Astronomical Union defined for the first time exactly what a planet is: it orbits the Sun, is round because of its own gravity – and has cleared its orbit of other objects. Pluto failed the third test: it became a dwarf planet, together with Ceres, Eris, Haumea and Makemake. You’ll find a memory trick for the eight here: planet mnemonic.
The two families
On the inside are the four rocky planets (Mercury, Venus, Earth, Mars), on the outside the four giants: the gas giants Jupiter and Saturn and the ice giants Uranus and Neptune. The asteroid belt circles in between. For the big picture, see our page on the solar system.
Planet Nine – the phantom
Odd orbital patterns among distant Kuiper Belt objects have fueled the hypothesis of an undiscovered Planet Nine far out for years – with several Earth masses and an orbit lasting thousands of years. Despite an intensive search, it hasn’t been found so far.
And beyond the solar system?
Since 1995, more than 6,400 exoplanets have been confirmed (NASA Exoplanet Archive, as of October 2026), and the number keeps climbing fast. Statistically, almost every star in the Milky Way has at least one planet – that would add up to hundreds of billions of worlds in our galaxy alone.
Frequently asked questions
Why is Pluto no longer a planet?
It hasn’t cleared its orbital zone of other objects – the third criterion of the 2006 planet definition. Since then it has been classed as a dwarf planet.
Which planets can you see with the naked eye?
Mercury, Venus, Mars, Jupiter and Saturn – the “wandering stars” known since ancient times. Uranus is a borderline case, and Neptune needs binoculars.
How many dwarf planets are there?
Five officially recognized ones: Pluto, Ceres, Eris, Haumea, Makemake. There are hundreds of candidates.
Is there a ninth planet?
Possibly – the Planet Nine hypothesis explains orbital anomalies in the Kuiper Belt. Direct proof is still missing.