Planet sizes: 8 sourced records
The eight planets · equatorial diameter. Values are shown in km and frozen to the 2026-10-24 snapshot used by the game.
What this topic measures
These are equatorial diameters. Rapidly rotating giant planets are wider at the equator than at the poles. The unit is km. This topic uses ratio scoring: a value half the target and a value twice the target are equally far away, so think in multiplicative bands rather than fixed steps.
A record is a named row in the frozen catalog, not necessarily a unique entity. Some topics contain several records with the same value, and a name round accepts any record at the closest distance. The table below is the complete answer set for this topic; there is no hidden shortlist.
All 8 records
| # | Record | Value | Year / release | Source | Note |
|---|---|---|---|---|---|
| 1 | Mercury | 4,879 km | — | Source ↗ | — |
| 2 | Mars | 6,792 km | — | Source ↗ | — |
| 3 | Venus | 12,104 km | — | Source ↗ | — |
| 4 | Earth | 12,756 km | — | Source ↗ | — |
| 5 | Neptune | 49,528 km | — | Source ↗ | — |
| 6 | Uranus | 51,118 km | — | Source ↗ | — |
| 7 | Saturn | 120,536 km | — | Source ↗ | — |
| 8 | Jupiter | 142,984 km | — | Source ↗ | — |
Every row links to the original source used for that record. Values are rounded for display only; the scoring engine uses the stored source value. The snapshot date and unit are part of the topic’s definition, so a current live figure may differ.
The table has 8 rows, one for each accepted record. It does not list every alias or spelling variant; the game’s name matcher handles those at answer time. If two records share a value, both remain separate rows.
The range and the gaps
The 8 records run from 4,879 km to 142,984 km. The median is 31,142 km, with a middle half from 10,776 km to 68,472.5 km. The largest adjacent gap is 69,418 km between Uranus and Saturn. Every record has a distinct value in this snapshot.
The highest listed records are Jupiter (142,984 km), Saturn (120,536 km), Uranus (51,118 km). The lowest are Mercury (4,879 km), Mars (6,792 km), Venus (12,104 km). Use these as anchors before you make a ratio or year estimate; the table below gives every value.
What the table does not tell you
These are single snapshot values in km for The eight planets · equatorial diameter. The table is not a time series, a range of typical values or a measure of uncertainty. A source can round, revise or use a different definition in a later release; the game uses the stored snapshot for every score. Read the source and the record label before treating a value as a current live measurement.
How to estimate this topic
Planet diameters are equatorial values, not volumes. Earth is the familiar 12,742 km anchor; Jupiter is more than ten Earths across. Use 10,000 km, 50,000 km and 140,000 km bands, and do not compare a diameter with a distance.
For a method that applies across topics, see the estimation guide. To practise this topic without changing a daily result, open the practice setup for Planet sizes. The setup opens first; it does not start a clock automatically.
Recent daily use
No completed daily flight has used this topic yet. The next flights may include it; the practice setup is available now without changing a daily score.
Source, licence and snapshot
The listed source is NASA · Planetary Fact Sheet ↗. Snapshot: 2026-10-24. Licence / attribution: "See source".
We select and transform source records for independently written game rules. The source material remains subject to its original licence. If a value looks wrong, send the topic, record, expected value and source through the contact form; do not send passwords or account credentials.
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