In Depth | Our Solar System – NASA Solar System Exploration Our solar system consists of our star, the Sun, and everything bound to it by gravity – the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids Beyond our own solar system, there are more planets than stars in the night sky
In Depth | Sun – NASA Solar System Exploration In Depth Introduction The Sun is a 4 5 billion-year-old yellow dwarf star – a hot glowing ball of hydrogen and helium – at the center of our solar system It’s about 93 million miles (150 million kilometers) from Earth and it’s our solar system’s only star Without the Sun’s energy, life as we know it could not exist on our home planet
In Depth | Earths Moon – NASA Solar System Exploration In Depth Introduction The brightest and largest object in our night sky, the Moon makes Earth a more livable planet by moderating our home planet's wobble on its axis, leading to a relatively stable climate It also causes tides, creating a rhythm that has guided humans for thousands of years
In Depth | Europa – NASA Solar System Exploration The similarities don’t end there Each planet in the inner solar system is less dense than its inner neighbor – Mars is less dense than Earth, which is less dense than Venus, which is less dense than Mercury The Galilean moons follow the same principle, being less dense the farther they are from Jupiter
In Depth | Enceladus – NASA Solar System Exploration About as wide as Arizona, Enceladus also has the whitest, most reflective surface in the solar system The moon creates a ring of its own as it orbits Saturn—its spray of icy particles spreads out into the space around its orbit, circling the planet to form Saturn’s E ring Enceladus is named after a giant in Greek mythology
In Depth | Kuiper Belt – NASA Solar System Exploration In Depth Introduction The Kuiper Belt is a large region in the cold, outer reaches of our solar system beyond the orbit of Neptune It's sometimes called the "third zone" of the solar system Astronomers think there are millions of small, icy objects in this region – including hundreds of thousands that are larger than 60 miles (100
In Depth | Saturn Moons – NASA Solar System Exploration Overview The Voyager and Pioneer flybys of the 1970s and 1980s provided rough sketches of Saturn’s moons But during its many years in Saturn orbit, NASA’s Cassini spacecraft discovered previously unknown moons, solved mysteries about known ones, studied their interactions with the rings and uncovered new mysteries – including the discovery on an ocean moon with potential ingredients for
In Depth | Moons – NASA Solar System Exploration Earth's Moon Martian Moons Phobos and Deimos Moons of the Giant Planets Moons of the Giant Planets Jupiter's menagerie of moons includes the largest in the solar system (Ganymede), an ocean moon (Europa) and a volcanic moon (Io) Many of Jupiter's outer moons have highly elliptical orbits and orbit backwards (opposite to the spin of the planet)