Solar System Explorer

Why Explore the Solar System?

Space is one of the first big science topics that children fall in love with. A five-year-old who has just learned that the Sun is a star, or that a day on Venus is longer than its year, will tell everyone at dinner. That wonder is a wonderful door into science and maths: comparing sizes, ordering things, reading data, and thinking about why things happen. The Solar System Explorer turns the planets into a place your child can visit, with Capy the capybara as the astronaut, so the facts come with a picture, a story and a reason to remember them.

The explorer is built so that the same page grows with your child. A kindergartener can simply fly the rocket, tap the glowing Sun and learn that Jupiter is the biggest planet. An upper primary pupil can work out how many seconds sunlight takes to reach Mars, or what a bathroom scale would show on the Moon, using real figures.

What Children Learn

• The planets and their order. Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune, counting out from the Sun. A favourite way to remember them is “My Very Excellent Mother Just Served Us Noodles”.
• Rocky planets, gas giants and ice giants. The four inner planets are small and rocky. Jupiter and Saturn are huge gas giants with no solid ground. Uranus and Neptune are ice giants, made mostly of water, ammonia and methane ices around a rocky centre.
• Scale. Children usually picture the planets as similar-sized balls quite close together. The Real sizes tab shows that about 11 Earths fit across Jupiter and about 109 across the Sun. The Distance walk shows that the outer planets are enormously far apart: Neptune is about 30 times further from the Sun than Earth.
• Days and years. A day is one spin of a planet; a year is one trip round the Sun. Comparing them gives some surprises: Jupiter spins in about 10 hours, and Mercury goes round the Sun in only 88 Earth days.
• Gravity. Gravity pulls things towards the middle of a planet, and it keeps the planets travelling round the Sun. Bigger, heavier worlds pull harder, which is why the Weigh me tab shows a bigger number on Jupiter and a much smaller one on the Moon.
• The Moon. Our Moon goes round Earth, shines only by reflecting sunlight, and seems to change shape through the month as we see different amounts of its sunlit side.
• The Sun is a star. It is the closest star to us, a giant ball of hot glowing gas, and every planet, dwarf planet, asteroid and comet in the solar system travels round it.

How to Use the Explorer

• Explore. The planets move round the Sun, the inner ones fastest. Tap any world, or one of the round buttons under the picture, and Capy’s rocket flies there and opens a fact card: order from the Sun, type, size, distance, a day, a year, moons, temperature and gravity, with fun facts. The Sun, the Moon, the dwarf planet Pluto, the asteroid belt and a comet have cards too. Use Pause orbits if the moving planets are hard to tap.
• Real sizes. The planets drawn side by side to the same scale, then the Sun added beside them. Ask your child to find Earth before telling them where it is.
• Distance walk. A long strip where every footstep is 10 million km. Scroll from the Sun, watch the readout count the distance, and use the jump buttons to fly along. Zoom in to see the inner planets clearly.
• Order game. Drag the planets onto the numbered spaces, or tap a planet to send it to the next space. Level 1 is the four rocky planets, level 2 all eight, and level 3 puts them in order of size from biggest to smallest.
• Missions. Eight questions at a time for your child’s level, made fresh each time from the planet data, with an explanation after every answer. Six or more correct earns a passport stamp.
• Weigh me. Type a weight in kilograms and see what a scale would show on every world.
• Passport. A stamp for every world visited, every mission passed and every solar system built. It is saved on your device only.

The Four Mission Levels

K2. Recognising Earth, Mars, Jupiter, Saturn, the Sun and the Moon from a picture; how many planets there are; the biggest and the smallest planet; the Red Planet; the planet with the big bright rings; the Sun is a star. Three answers to choose from, so reading load stays light. Read the questions aloud for children who are not reading yet.

P1 and P2. The order of the planets, which planet comes next, the closest and furthest planet, which of two planets is hotter or colder, why we have day and night, and the simple shapes of the Moon: crescent, half and full.

P3 and P4. Sorting rocky planets, gas giants and ice giants; comparing sizes with “about how many Earths wide”; which of two planets takes longer to go round the Sun and why; what a day and a year are; and gravity basics such as what keeps the planets in orbit and where you would jump highest.

P5 and P6. Calculating with real data. How many Earth days do four Mercury years take? If a scale shows 30 kg on Earth and Mars pulls about 0.4 times as hard, what would it show on Mars? Light travels about 300,000 km every second, so how many seconds does sunlight take to cross 150 million km to Earth (about 500 seconds, a little over 8 minutes)? In a scale model where one step is 10 million km, how many steps is Saturn from the Sun? These are good practice for multiplication, division, rounding and large numbers, and every answer comes with the working.

Ideas for Home and the Classroom

• A real distance walk. Take the scale outside: let one big step be 10 million km and walk from a “Sun” at the gate. Earth is only 15 steps away, Jupiter about 78 and Neptune about 450, further than most school fields. Children never forget how empty space is after this.
• Fruit planets. If the Sun were as wide as a front door, Earth would be about the size of a large pea and Jupiter about the size of a grapefruit. Line up fruit and peas to make the Real sizes picture in the kitchen.
• Day and night with a torch. Darken the room, use a torch as the Sun and spin a ball slowly. Stick a small sticker on Singapore or Malaysia and watch it move from day into night.
• Moon diary. For a month, draw the Moon every clear evening. Compare the drawings with the Moon shapes in the P1–P2 missions. The full Moon comes back about every 29½ days.
• Planet posters. Print the colouring sheet, label the planets with the word bank, and add one fact from each fact card. Older pupils can add the distance in millions of km and the length of a year.
• Data detectives. Upper primary pupils can make a table from the fact cards and look for patterns: do planets further from the Sun always have longer years? (Yes.) Are they always colder? (Mostly, but Venus is hotter than Mercury because of its thick air.)

About the Numbers

The figures come from widely published planetary data, such as NASA’s planetary fact sheets, and are rounded so children can use them: distances are averages, because the planets’ paths are slightly stretched; temperatures are typical values; and the gravity numbers are rounded ratios to Earth’s. The number of known moons changes as astronomers find new small ones, so the explorer says “more than 90” for Jupiter and “more than 250” for Saturn rather than an exact count. A “day” on the fact cards means sunrise to sunrise. The moving orbit view is a picture, not a scale model; the Real sizes and Distance walk tabs are the to-scale views.

Printing

Print a worksheet uses the mission level that is chosen in the Missions tab and makes ten new questions with an answer page on its own sheet, so it can be marked later. Print a colouring sheet gives a “My Solar System” page with the Sun and the eight planets in order to colour and label, a word bank and a few small tasks. Save a space picture saves the solar system picture with Capy’s rocket and your stamp count to your device.

Nothing to Install, Nothing Uploaded

The Solar System Explorer runs entirely in your browser on any phone, tablet or computer, with no account and no download. All the pictures are drawn on the page, so it keeps working without an internet connection once loaded. Passport stamps are kept only in your own browser, and nothing is sent anywhere.