Planet Size & Distance Explorer
See the Sun and planets drawn to true scale, tap any world for its fact card, and find out how old you would be — and how much you would weigh — on other planets.
The Solar System has eight planets — Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune — orbiting the Sun, which holds 99.8% of its total mass. Remember the order with "My Very Educated Mother Just Served Us Noodles". Pluto was reclassified as a dwarf planet in 2006 because it has not cleared its orbit.
How far is each planet?
Average distance from the Sun. 1 AU (astronomical unit) = 149.6 million km, the average Sun–Earth distance.
| Planet | Distance (AU) | Million km | Sunlight takes | Car at 100 km/h | Size × Earth |
|---|
Your weight on other worlds
Your mass stays the same everywhere; your weight (the pull of gravity) changes.
Your age on other planets
A “year” is one trip around the Sun. Faraway planets take much longer, so you would be younger there.
| Planet | Your age | Next birthday there |
|---|
Remember the order
“My Very Educated Mother Just Served Us Noodles” — one word for each planet, from the Sun outward.
Why is Pluto not a planet?
In 2006 the International Astronomical Union (IAU) decided that a planet must:
- orbit the Sun,
- be massive enough to pull itself into a nearly round shape, and
- have cleared its orbit of other objects.
Pluto passes the first two tests but shares its path with many icy bodies of the Kuiper Belt, so it is a dwarf planet — like Ceres, Eris, Haumea and Makemake. Pluto is smaller than our Moon (2,376 km across vs 3,475 km).
Amazing Solar System facts
Numbers to impress your class.
Our Solar System, to scale
Textbook pictures squeeze the planets close together and make them look similar in size. Here every circle and every gap uses the real numbers.
Compare sizes
All circles share one scale. Turn the Sun on to see how tiny even Jupiter is beside it.
Travel outward
Switch to Distance and scroll. Zoom in to separate the crowded inner planets.
Open fact cards
Tap any planet for its size, mass, gravity, day, year, temperature and moons — then share it.
Make it personal
Enter your mass and birthday to find your weight and age on every planet.
The Sun and its family
The Sun is a star holding 99.8% of the Solar System’s mass. Eight planets orbit it: four small rocky planets (Mercury, Venus, Earth, Mars), two gas giants (Jupiter, Saturn) and two ice giants (Uranus, Neptune). The asteroid belt lies between Mars and Jupiter.
Mass vs weight
Weight W = m × g
A 40 kg student weighs 40 × 9.8 = 392 N on Earth but only 40 × 1.62 ≈ 65 N on the Moon — about one-sixth. The mass is still 40 kg.
Day vs year
A day is one spin on the axis; a year is one trip around the Sun. Planets farther out move slower on bigger orbits, so their years are longer — Neptune’s year lasts about 165 Earth years.
Light travel time
Light moves at about 3 × 10⁵ km/s. Sunlight reaches Earth in about 8 min 20 s, so we always see the Sun as it was a few minutes ago.
Planet Size & Distance Explorer — your questions
How many planets are there and what is their order?
There are eight planets. In order from the Sun they are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune. The first four are small rocky planets, Jupiter and Saturn are gas giants, and Uranus and Neptune are ice giants. The asteroid belt lies between Mars and Jupiter.
Why is Pluto not a planet any more?
In 2006 the International Astronomical Union ruled that a planet must orbit the Sun, be massive enough to pull itself into a nearly round shape, and have cleared its orbit of other objects. Pluto passes the first two tests but shares its path with icy bodies of the Kuiper Belt, so it is a dwarf planet, like Ceres and Eris.
What would I weigh on the Moon and on Mars?
Weight is W = m × g, and your mass never changes. A 40 kg student weighs 40 × 9.8 = 392 N on Earth, but only 40 × 1.62 ≈ 65 N on the Moon, about one sixth. On Mars, where g is 3.7 m/s², the same student would weigh about 148 N — a little over a third of their Earth weight.
What is the difference between mass and weight?
Mass is the amount of matter in an object, measured in kilograms, and it is the same everywhere in the universe. Weight is the force of gravity acting on that mass, measured in newtons, and it changes with the value of g. That is why astronauts float in orbit without losing any mass at all.
How long does sunlight take to reach the Earth?
About 8 minutes and 20 seconds. Light travels at roughly 3 × 10⁵ km/s and the average Sun-Earth distance is 149.6 million km, which is defined as one astronomical unit (AU). So we always see the Sun as it was a few minutes ago, and sunlight reaching Neptune is more than four hours old.
Which is the biggest planet and which is the hottest?
Jupiter is the biggest, about 142,984 km across — more than eleven Earths side by side. Venus is the hottest at around 464 °C, hotter even than Mercury which is closer to the Sun, because Venus has a thick carbon dioxide atmosphere that traps heat in a runaway greenhouse effect.
What is the difference between a day and a year on a planet?
A day is one spin of the planet on its axis; a year is one complete orbit around the Sun. Planets farther out travel slower along much longer orbits, so their years are far longer — Neptune's year lasts about 165 Earth years, while Jupiter spins so fast that its day is under 10 hours.