Can you put five things in order from smallest to largest?
Each round deals five objects from a collection of 69, which runs from a proton to the observable universe. Tap them from smallest to largest. A right order adds one to your streak, and later rounds bring the objects closer in size, so the ranking gets harder the longer you last.
How to play
- Five photo cards fill the board, each with a name and a category (stacked on a phone). Tap the smallest first, then the next, until every card has a number; the last card is placed for you.
- Changed your mind? Tap a numbered card to take it back, along with every card after it.
- Press Check order. Every card then shows its size and its right place: green where you put it right, red where you did not.
- A right order adds one to your streak and the next round follows. One card out of place ends the run. There is no timer, and the pictures are not to scale.
- Your result is saved in this browser. Once enough people have played a game, the results also show how your score ranks, and you can copy or share an image of your result, or replay.
Tips for playing
Place the extremes first: the smallest and the largest are usually the easiest to spot. Then compare the middle cards two at a time, and think about how each one is measured: a person by height, a whale by length, a planet by its diameter.
All 69 objects, smallest to largest
Show all 69 objects
| Object | Category | Size |
|---|---|---|
| Proton | Subatomic particle | ~1.68 femtometres |
| Hydrogen atom | Atom | ~0.106 nanometres |
| DNA double helix | Molecule | ~2 nanometres |
| Ribosome | Molecular machine | ~25 nanometres |
| SARS-CoV-2 virus | Virus | ~90 nanometres |
| T4 bacteriophage | Virus | 120 nanometres |
| Mimivirus | Giant virus | ~750 nanometres |
| E. coli bacterium | Microorganism | ~2 micrometres |
| Red blood cell | Human cell | ~7.5 micrometres |
| Tardigrade | Microscopic animal | ~0.5 mm |
| Honeybee | Insect | ~13 mm |
| US quarter | Everyday object | 24.26 mm |
| Golf ball | Everyday object | 42.67 mm |
| House mouse | Animal | ~10 cm |
| Football | Everyday object | ~22 cm |
| Emperor penguin | Bird | ~1.15 m |
| Human | Person | ~1.75 m |
| African elephant | Animal | ~3.96 m |
| Giraffe | Animal | ~5.5 m |
| SUE the T. rex | Dinosaur | ~12 m |
| Blue whale | Animal | ~30 m |
| Leaning Tower of Pisa | Building | 58.36 m |
| Boeing 747-8 | Aircraft | 76.25 m |
| General Sherman tree | Plant | 83.8 m |
| Statue of Liberty | Monument | 93 m |
| International Space Station | Human-made structure | 109 m |
| Saturn V rocket | Rocket | 111 m |
| RMS Titanic | Ship | 269 m |
| Eiffel Tower | Building | 330 m |
| Empire State Building | Building | 443 m |
| Bennu | Asteroid | 492 m |
| Burj Khalifa | Building | 828 m |
| Golden Gate Bridge | Bridge | 1,280 m |
| Mount Fuji | Mountain | 3,776 m |
| Comet 67P | Comet | 4.1 km |
| Mount Everest | Mountain | 8,849 m |
| Mauna Kea | Volcano | 10,211 m |
| Phobos | Moon | 27 km |
| Grand Canyon | Canyon | 446 km |
| Vesta | Asteroid | 525 km |
| Olympus Mons | Martian volcano | ~600 km |
| Ceres | Dwarf planet | 940 km |
| Great Barrier Reef | Coral reef system | ~2,300 km |
| Pluto | Dwarf planet | 2,377 km |
| The Moon | Moon | 3,476 km |
| Mercury | Planet | 4,880 km |
| Ganymede | Moon | 5,268 km |
| Mars | Planet | 6,792 km |
| Venus | Planet | 12,104 km |
| Earth | Planet | 12,756 km |
| Neptune | Planet | 49,528 km |
| Uranus | Planet | 51,118 km |
| Saturn | Planet | 120,536 km |
| Jupiter | Planet | 142,984 km |
| The Sun | Star | 1.4 million km |
| Betelgeuse | Red supergiant | 1.4 billion km |
| M87* black hole | Supermassive black hole | ~38 billion km |
| Ring Nebula | Planetary nebula | ~1 light-year |
| Pillars of Creation | Nebula | ~4 light-years |
| Crab Nebula | Supernova remnant | 6 light-years |
| Orion Nebula | Star-forming nebula | 24 light-years |
| Omega Centauri | Globular cluster | 150 light-years |
| Tarantula Nebula | Star-forming nebula | ~1,000 light-years |
| Large Magellanic Cloud | Galaxy | ~15,000 light-years |
| Whirlpool Galaxy | Galaxy | ~60,000 light-years |
| Milky Way | Galaxy | 100,000 light-years |
| Andromeda | Galaxy | 260,000 light-years |
| Coma Cluster | Galaxy cluster | 20+ million light-years |
| Observable universe | Universe | ~92 billion light-years |
Sizes measure different dimensions, such as height, length or diameter; each card in the game names the one it uses.
Frequently asked questions
How many objects can come up?
69, in 44 categories, from a proton to the observable universe. Each round deals five of them, and objects you have not seen in the current run come first.
Do the rounds get harder?
Yes. The first two rounds can mix anything on the scale, so a virus can meet a galaxy. After 2 right orders, the five objects in a round span at most 8 orders of magnitude; after 5, at most 4; and after 10, at most 2.5. Where too few objects fit, the range widens a little.
Which objects never appear in the same round?
7 pairs are within 10% of each other, too close to rank fairly, so they are never dealt together: the Great Barrier Reef and Pluto; Mercury and Ganymede; Venus and Earth; Neptune and Uranus; a Boeing 747-8 and the General Sherman tree; the International Space Station and a Saturn V rocket; Mount Fuji and Comet 67P.
Are the pictures to scale?
No. Each picture is cropped to fill its card. Rank the objects by their real size, measured by the dimension that suits each one, such as height, length or diameter.
What happens if I get the order wrong?
The run ends and your streak is saved. Every card shows its size and its right place, and the answer review below the board lists each round you played, smallest to largest, beside your order. Press Replay to start again.
Neighbours on the size ladder
Lined up by size, the 69 objects span about 42 orders of magnitude, from a proton to the observable universe. Each order of magnitude is a factor of ten, so neighbours on the list are often very different kinds of thing.
The asteroid Bennu (492 m) sits between the Empire State Building (443 m) and the Burj Khalifa (828 m). Olympus Mons (~600 km) sits between Vesta (525 km) and Ceres (940 km). Mauna Kea (10,211 m) sits between Mount Everest (8,849 m) and Phobos (27 km).
How the sizes are measured
Every card names the dimension it compares. Buildings and people are measured by height, ships, aircraft and many animals by length, and planets by their equatorial diameter, excluding rings.
Very small and very large objects have no sharp edge. A proton’s size is a charge radius rather than a hard surface, a star’s diameter depends on the model used, and nebulae and galaxies are given by their approximate extent. The largest sizes are given in light-years: one light-year, the distance light travels in a year, is about 9.46 trillion kilometres.
Measurements come from NASA, NIST, museums and the primary source linked for each object in the game’s credits, with photographs, micrographs, telescope images and visualizations labelled on each card.
Sources
Source: NASA and per-object references
A curated size collection, not one statistical series. Each object specifies a dimension and links its reference in How to Play. Representative sizes, estimates and bounds are identified there; pictures are not to scale.
Found an incorrect answer or a source that needs updating? Send a correction with the game name and a reference.