Spacecraft are how we visit our solar system. As of November 2026, it has eight planets that circle the Sun, and the Sun is at the center. Earth is the third one from the Sun. About 1.3 million Earths could fit inside the Sun, and it holds 99.8 percent of all the mass in our solar system. Sunlight takes about eight minutes to reach Earth. Distances out here are long. They are measured in astronomical units. One astronomical unit (AU) is the distance from the Sun to Earth, about 93 million miles (150 million kilometers). Let's follow the spacecraft that have gone out to visit.

Jupiter is the largest planet in our solar system. It is more than twice as massive as all the other planets combined. A day on Jupiter lasts only about ten hours, the shortest day of any planet. Jupiter is a gas giant, so it does not have a true solid surface. Its Great Red Spot is a giant storm that is bigger than Earth. NASA's Juno spacecraft entered orbit around it on July 4, 2016. The trip was nearly three billion kilometres.

Some moons are worlds of their own. Galileo Galilei discovered Jupiter's four largest moons: Io, Europa, Ganymede and Callisto. Ganymede, a moon of Jupiter, is the largest moon in the solar system. Io is covered in hundreds of volcanoes. It is the most volcanically active world in the Solar System. Europa is thought to have a liquid-water ocean beneath its icy crust. In 2005 NASA's Cassini spacecraft found that Saturn's moon Enceladus sends plumes of icy particles out into space. Enceladus has an ocean hidden beneath its icy surface. Titan is the only moon in our solar system known to have a substantial atmosphere.

Saturn has a spectacular set of rings around it. They are made of millions of separate pieces. Most are small, from tiny dust-sized icy grains to chunks as big as a house. NASA's Cassini became the first spacecraft to orbit Saturn. The Voyager spacecraft first spotted a hexagon-shaped pattern in Saturn's atmosphere.

Clyde Tombaugh discovered Pluto in 1930. It was once counted as a planet but, as of November 2026, is called a dwarf planet. As of November 2026, astronomers have recognized five dwarf planets. Pluto's oval-shaped orbit takes it from about 30 AU to about 49 AU away from the Sun. NASA's New Horizons made the first flyby of Pluto, in July 2015. In 2019 it flew past a second target, Arrokoth. Pluto has five moons: Charon, Styx, Nix, Kerberos and Hydra. Pluto and Charon are often called a double planet.

Some spacecraft leave the planets behind. Voyager 1 entered interstellar space in August 2012. Even the Sun is on a trip: it orbits the center of the Milky Way galaxy and carries the planets, asteroids and comets with it.

Words to know

• spacecraft: ship for space
• astronomical: about the stars
• plumes: rising streams
• atmosphere: layer of gas
• interstellar: between stars