Our Solar System is a collection of eight planets, millions of moons and innumerable small objects orbiting the Sun. These include dwarf planets and countless asteroids, comets and other small, icy objects.
The Sun is the largest object in the Solar System, with its enormous mass making it the closest star to Earth. The Sun is also the source of a stream of energy called the solar wind that flows outward from the Sun through the whole Solar System. This wind causes the auroras, or displays of colored light in the night sky.
Inside the Sun are eight planets, ranging in size from Mercury to Jupiter. Each planet has its own unique surface, including rocky, icy and gaseous surfaces.
Each planet is surrounded by a ring of other planets, moons and smaller bodies called planetary rings. The rings are a collection of rocky, metal and ice bodies that are believed to be leftovers from the early days of the Solar System.
Some of the planetary rings have rocky bodies that form continents. Others have more volatile substances like ice, water and ammonia that melt at high temperatures.
There are also a few planets that are made of gases and don’t have rocky or icy surfaces. These are the “Jupiter-like” planets, which include Jupiter and Saturn. These giant planets are also known as gas giants and have a lot of water in their interiors.
The largest planets are the Jovian planets, which are gas giants that are made mainly of hydrogen and helium. The next largest are the Uranus and Neptune planets, which are icy giants that have a lot of water in their interiors.
Our Solar System is a very special place, and it’s our mission to make sure it stays that way! To help us achieve this goal, we’re creating new astronomy and space science education programs that connect people of all ages to our amazing universe.
To make that happen, we’re working closely with a network of community partners and astronomy societies. We send them monthly mailings of the latest NASA materials, and they put those materials on display boards in their museums, libraries and other places where children can learn about the universe.
We’re also helping to support the growth of a large network of astronomy educators and volunteers. We’re helping them meet the challenges of delivering astronomy and space science in the schools by making their resources easy to use and by supporting their efforts to strengthen existing science education programs.
The outer edge of our solar system is a region called the Kuiper Belt. This spherical belt contains icy bodies that are almost as big or larger than Pluto and make slow orbits around the Sun.
Beyond the Kuiper Belt is another spherical shell called the Oort Cloud, which may contain more than a trillion icy bodies. The Oort Cloud is where long-period comets, or objects that take more than 200 years to orbit the sun, are thought to originate.