Ganymede
JupiterThe largest moon in the solar system, bigger than the planet Mercury. Ganymede is the only moon known to have its own magnetic field.
It is the only moon with its own magnetosphere.
5,268 kmDiscovered 1610
Solar System
Explorer
Scroll to begin your journey through the cosmos
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The Sun
Our stellar powerhouse
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A nearly perfect sphere of hot plasma at the heart of our solar system. The Sun accounts for 99.86% of the total mass of the solar system and provides the energy that sustains life on Earth.
Light from the Sun takes 8 minutes and 20 seconds to reach Earth
The Sun converts 4 million tons of matter into energy every second
It has enough fuel to burn for another 5 billion years
Over one million Earths could fit inside the Sun
Size vs Earth
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Mercury
The swift messenger
Orbital Period: 88 Earth daysDistance: 0.387 AU · Eccentricity: 0.2056
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The smallest planet in our solar system and closest to the Sun. Mercury is only slightly larger than Earth's Moon and has virtually no atmosphere to retain heat.
A year on Mercury is just 88 Earth days
Despite being closest to the Sun, it's not the hottest planet
Mercury has no atmosphere, no moons, and no rings
Its surface temperature swings by over 600°C between day and night
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57.9M KM FROM THE SUN
Venus
Earth's scorching twin
Orbital Period: 225 Earth daysDistance: 0.723 AU · Eccentricity: 0.0068
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Often called Earth's twin due to similar size, Venus is actually the hottest planet thanks to a runaway greenhouse effect. Its thick atmosphere traps heat, making the surface hot enough to melt lead.
Venus spins backwards compared to most other planets
A day on Venus is longer than its year
Surface pressure is 90 times greater than Earth's
It's the brightest natural object in the night sky after the Moon
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108.2M KM FROM THE SUN
Earth
Our pale blue dot
Orbital Period: 365.25 Earth daysDistance: 1.0 AU · Eccentricity: 0.0167
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The only known planet to harbor life. Earth's liquid water, protective magnetosphere, and nitrogen-oxygen atmosphere create the perfect conditions for the incredible diversity of life we see today.
Earth is the densest planet in the solar system
70% of the surface is covered in water
Earth's magnetic field protects us from solar radiation
The planet is approximately 4.54 billion years old
149.6M KM FROM THE SUN
Mars
The red frontier
Orbital Period: 687 Earth daysDistance: 1.5 AU · Eccentricity: 0.0934
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Known as the Red Planet for its iron oxide-rich surface. Mars features the tallest volcano and deepest canyon in the solar system, and is the primary target for future human exploration.
Mars has the tallest volcano in the solar system: Olympus Mons at 21.9 km
A day on Mars is only 37 minutes longer than an Earth day
Mars has two tiny moons: Phobos and Deimos
Evidence suggests Mars once had flowing liquid water on its surface
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227.9M KM FROM THE SUN
Entering the Outer Solar System
Mars
Jupiter
550.6M km
The asteroid belt — a vast region of rocky debris
Jupiter
King of the planets
Orbital Period: 4,333 Earth daysDistance: 5.2 AU · Eccentricity: 0.0484
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The largest planet in our solar system, Jupiter is a gas giant with a mass more than twice that of all other planets combined. Its iconic Great Red Spot is a storm that has raged for centuries.
Jupiter has the shortest day of any planet — just 10 hours
The Great Red Spot is a storm larger than Earth
Jupiter has at least 95 known moons
Its magnetic field is 20,000 times stronger than Earth's
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778.5M KM FROM THE SUN
Saturn
The jewel of the solar system
Orbital Period: 10,759 Earth daysDistance: 9.5 AU · Eccentricity: 0.0542
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Famous for its stunning ring system, Saturn is a gas giant made mostly of hydrogen and helium. Its rings are made of billions of particles of ice and rock, ranging from tiny grains to house-sized chunks.
Saturn's rings span up to 282,000 km but are only about 10 meters thick
Saturn is so light it would float in water (if you had a big enough bathtub)
Wind speeds on Saturn can reach 1,800 km/h
Saturn has 146 known moons — the most of any planet
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1,434M KM FROM THE SUN
Uranus
The tilted ice giant
Orbital Period: 30,687 Earth daysDistance: 19.2 AU · Eccentricity: 0.0472
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Uranus is unique among planets — it rotates on its side, with an axial tilt of 98 degrees. This ice giant's blue-green color comes from methane in its atmosphere absorbing red light.
Uranus rotates on its side with an axial tilt of 98 degrees
It was the first planet discovered using a telescope (1781)
A year on Uranus lasts 84 Earth years
Its blue-green color comes from methane in the atmosphere
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2,871M KM FROM THE SUN
Neptune
The windswept world
Orbital Period: 60,190 Earth daysDistance: 30.1 AU · Eccentricity: 0.0086
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The most distant planet from the Sun, Neptune is a dark, cold world with the strongest winds in the solar system reaching speeds of 2,100 km/h. It was the first planet found by mathematical prediction.
Neptune has the strongest winds in the solar system — up to 2,100 km/h
It was discovered in 1846 by mathematical prediction before it was seen
One year on Neptune equals 165 Earth years
Its moon Triton orbits in the opposite direction to Neptune's rotation
Size vs Earth
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4,495M KM FROM THE SUN
Notable Moons
The most fascinating worlds orbiting our planets
Jupiter's Moons
Europa
JupiterAn ice-covered world with a vast subsurface ocean that may contain more than twice the water of all Earth's oceans combined.
Its hidden ocean makes it a top candidate for extraterrestrial life.
3,122 kmDiscovered 1610
Io
JupiterThe most volcanically active body in the solar system, with hundreds of volcanoes and lava flows stretching hundreds of kilometers.
Over 400 active volcanoes reshape its surface constantly.
3,643 kmDiscovered 1610
Callisto
JupiterThe most heavily cratered object in the solar system. Callisto may harbor a subsurface ocean beneath its ancient, battered surface.
Its surface has remained largely unchanged for 4 billion years.
4,821 kmDiscovered 1610
Saturn's Moons
Titan
SaturnThe only moon with a thick atmosphere and the only world besides Earth with stable surface liquids -- lakes and seas of liquid methane and ethane.
It has rain, rivers, and seas -- all made of liquid methane.
5,150 kmDiscovered 1655
Enceladus
SaturnA small icy moon that shoots enormous geysers of water vapor and ice particles from its south pole, hinting at a warm subsurface ocean.
Its geysers spray water ice into space, feeding Saturn's E ring.
504 kmDiscovered 1789
Neptune's Moons
Triton
NeptuneNeptune's largest moon orbits in the opposite direction of the planet's rotation, suggesting it was captured from the Kuiper Belt.
Its retrograde orbit will eventually cause it to be torn apart by Neptune's gravity.
2,707 kmDiscovered 1846
Humanity's Reach
The missions that expanded our understanding of the cosmos
Voyager 1
NASA1977 — Present
Target: Outer Solar System / Interstellar Space
Launched to study Jupiter and Saturn, Voyager 1 continued past the outer planets and became the first human-made object to enter interstellar space in 2012.
Discovered active volcanoes on Jupiter's moon Io and entered interstellar space at over 24 billion km from Earth.
Active
Voyager 2
NASA1977 — Present
Target: Outer Solar System / Interstellar Space
The only spacecraft to have visited all four outer planets — Jupiter, Saturn, Uranus, and Neptune — providing unprecedented close-up data on each.
Revealed Neptune's Great Dark Spot and discovered 10 new moons across Uranus and Neptune.
Active
Cassini-Huygens
NASA / ESA1997 — 2017
Target: Saturn
Orbited Saturn for 13 years while the Huygens probe landed on Titan, becoming the first landing in the outer solar system.
Discovered liquid methane seas on Titan and water-ice geysers erupting from Enceladus.
Completed
New Horizons
NASA2006 — Present
Target: Pluto / Kuiper Belt
Performed the first-ever flyby of Pluto in 2015, then continued on to explore the Kuiper Belt object Arrokoth in 2019.
Revealed Pluto's heart-shaped nitrogen glacier and a surprisingly complex, geologically active surface.
Active
Juno
NASA2011 — Present
Target: Jupiter
A solar-powered orbiter studying Jupiter's composition, gravity field, magnetic field, and polar magnetosphere to understand its origin and evolution.
Found that Jupiter's core is not solid but a diffuse mix of heavy elements blending into the mantle.
Active
Curiosity
NASA2011 — Present
Target: Mars
A car-sized rover exploring Gale Crater on Mars, studying the planet's climate and geology to determine if Mars ever had conditions suitable for microbial life.
Found evidence that Gale Crater once held a freshwater lake with all the chemical ingredients needed for life.
Active
Perseverance
NASA2020 — Present
Target: Mars
Exploring Jezero Crater to seek signs of ancient life and collect rock samples for future return to Earth. Deployed the Ingenuity helicopter for the first powered flight on another planet.
Achieved the first powered, controlled flight on another planet with the Ingenuity helicopter.
Active