The question of how many satellites the Sun has requires understanding astronomical terminology. In the strictest sense, the Sun does not have “satellites,” because a satellite is defined as an object that orbits a larger body, such as a planet or a moon. Objects that orbit the Sun are classified as planets, dwarf planets, or small Solar System bodies. The true count of Sun-orbiting bodies ranges from a definitive few to an uncountable multitude.
Defining the Terminology
In astronomy, the term “satellite” is reserved for a celestial body that orbits another body, which is itself not a star. Earth’s Moon, for instance, is a natural satellite because it orbits the Earth. Conversely, Earth is a planet because it orbits the Sun, which is a star.
This distinction is fundamental to understanding the organization of our cosmic neighborhood. Bodies that revolve directly around the Sun include the major planets and smaller objects like asteroids and comets. Using the incorrect term “satellite” for these Sun-orbiting bodies conflates the relationship between a planet and its moon with the relationship between a star and its planets.
The Primary Orbiters: Planets
The most definitive number of large bodies orbiting the Sun is eight, representing the major planets of the Solar System. This official count was established in 2006 by the International Astronomical Union (IAU) when it created a formal, three-part definition for a planet. To qualify, a celestial body must orbit the Sun, possess enough mass for its gravity to pull it into a nearly round shape, and have cleared the neighborhood around its orbit.
The third criterion is the most restrictive and was the central reason for the reclassification of Pluto. “Clearing the neighborhood” means the object must be gravitationally dominant in its orbital zone, either by sweeping up smaller bodies or flinging them away. The eight bodies that satisfy all three criteria are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
Jupiter, for example, is so massive that it dominates its orbit, with all other objects in that region either orbiting Jupiter or having been ejected long ago. Pluto, however, shares its orbital zone, known as the Kuiper Belt, with numerous other large, icy bodies. Because Pluto is not gravitationally dominant, it failed to meet the third IAU requirement. This specific definition provides a clear and finite count for the largest objects circling the Sun.
Expanding the Count: Dwarf Planets and Minor Bodies
Beyond the eight major planets, the count of Sun-orbiting bodies rapidly expands and becomes less precise. The IAU created the classification of “dwarf planet” for objects that meet the first two planet criteria—orbiting the Sun and being nearly round—but fail to meet the third. Only five are officially recognized by the IAU: Ceres, Pluto, Haumea, Makemake, and Eris.
Ceres is located in the main Asteroid Belt between Mars and Jupiter, while the others are Trans-Neptunian Objects far beyond Neptune’s orbit. While only five are officially named, astronomers estimate that there may be hundreds, or even thousands, of dwarf planets waiting to be discovered or confirmed, particularly in the Kuiper Belt and beyond.
The count grows even larger when considering the small Solar System bodies, which include millions of asteroids, comets, and meteoroids. The main Asteroid Belt alone contains hundreds of thousands of cataloged objects, most of which are irregularly shaped and too small to be considered dwarf planets. Comets originate primarily from the distant, icy Oort Cloud and the Kuiper Belt. The Sun has an effectively infinite number of small, icy, and rocky bodies in orbit around it, meaning the total number depends entirely on the minimum size chosen for the count.