The Sun holds the solar system together, keeping everything – from the biggest planets to the smallest
debris – in its orbit.
The Sun is the largest object in our solar system. The Sun’s volume
would need 1.3 million Earths to fill it. Its gravity holds the solar system together, keeping
everything from the biggest planets to the smallest bits of debris in orbit around it.
The smallest planet in our solar system and nearest to the Sun, Mercury is only slightly larger than
Earth's Moon.
Despite its proximity to the Sun, Mercury is not the hottest planet in our solar
system – that title belongs to nearby Venus, thanks to its dense atmosphere.
Venus is the second planet from the Sun and is Earth’s closest planetary neighbor. It’s one of the four
inner, terrestrial (or rocky) planets, and it’s often called Earth’s twin because it’s similar in size
and density.
TIt’s the hottest planet in our solar system, even though Mercury is closer to
the Sun. Surface temperatures on Venus are about 900 degrees Fahrenheit (475 degrees Celsius) – hot
enough to melt lead.
Earth—our home planet—is the only place we know of so far that’s inhabited by living things. It's also
the only planet in our solar system with liquid water on the surface.
Our home planet is the
third planet from the Sun, and the only place we know of so far that’s inhabited by living things. While
Earth is only the fifth largest planet in the solar system, it is the only world in our solar system
with liquid water on the surface.
Mars is a dusty, cold, desert world with a very thin atmosphere. There is strong evidence Mars was –
billions of years ago – wetter and warmer, with a thicker atmosphere. Mars is also a dynamic planet with
seasons, polar ice caps, canyons, extinct volcanoes, and evidence that it was even more active in the
past.
Mars is one of the most explored bodies in our solar system, and it's the only planet
where we've sent rovers to roam the alien landscape.
Jupiter is more than twice as massive than the other planets of our solar system combined. The giant
planet's Great Red Spot is a centuries-old storm bigger than Earth
Jupiter has a long history of
surprising scientists – all the way back to 1610 when Galileo Galilei found the first moons beyond
Earth. That discovery changed the way we see the universe. Jupiter's familiar stripes and swirls are
actually cold, windy clouds of ammonia and water, floating in an atmosphere of hydrogen and helium.
Saturn is the sixth planet from the Sun and the second-largest planet in our solar system.
Adorned
with thousands of beautiful ringlets, Saturn is unique among the planets. It is not the only planet to
have rings – made of chunks of ice and rock – but none are as spectacular or as complicated as
Saturn's.
Like fellow gas giant Jupiter, Saturn is a massive ball made mostly of hydrogen and
helium.
Uranus is the seventh planet from the Sun, and has the third-largest diameter in our solar system. It was
the first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William
Herschel, although he originally thought it was either a comet or a star.
Uranus is about four
times wider than Earth. If Earth were a large apple, Uranus would be the size of a basketball.
Uranus takes about 17 hours to rotate once (a Uranian day), and about 84 Earth years to complete an
orbit of the Sun (a Uranian year).
Dark, cold, and whipped by supersonic winds, ice giant Neptune is the eighth and most distant planet in
our solar system.
More than 30 times as far from the Sun as Earth, Neptune is the only planet in
our solar system not visible to the naked eye and the first predicted by mathematics before its
discovery. In 2011 Neptune completed its first 165-year orbit since its discovery in 1846.
NASA's Voyager 2 is the only spacecraft to have visited Neptune up close. It flew past in 1989 on its
way out of the solar system.
