ALL ANSWERS · SPACE · DAILY No. 40 · OCTOBER 13, 2026
Size It Up Space answer: October 13
The five Space silhouettes for October 13, with the true sizes. If you have not played yet, this page is a spoiler — play these five first, then come back to argue with the numbers.
Day 40 ran from Atlas (30.2 km) to the Sun (1,391,000 km). The widest gap was round 4, Sun against LHS 1140, at 4.6×; the closest call was round 2, Enceladus against Proteus, only 1.2× apart — the kind of round that separates a 90 from a 60.
SPOILER · TODAY’S FIVE
You have not finished today’s puzzle on this device. The answers below are blurred so you can still play first.
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ROUND 1
Earth (mean diameter) vs Ganymede (Jupiter’s moon · mean diameter)
Ganymede · reference · 5,262 km Earth · true diameter · 12,740 km 2.4× wider than Ganymede
Earth has a mean diameter of about 12,742 km. This is the body’s size, not an orbital distance.
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ROUND 2
Enceladus (Saturn’s moon · mean diameter) vs Proteus (Neptune’s moon · mean diameter)
Proteus · reference · 416 km Enceladus · true diameter · 504.2 km 1.2× wider than Proteus
Enceladus, a moon of Saturn, has a mean diameter of about 504.2 km. This is the body’s size, not an orbital distance.
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ROUND 3
Atlas (Saturn’s moon · mean diameter) vs Prometheus (Saturn’s moon · mean diameter)
Prometheus · reference · 86.2 km Atlas · true diameter · 30.2 km 2.9× shorter than Prometheus
Atlas, a moon of Saturn, has a mean diameter of about 30.2 km. This is the body’s size, not an orbital distance.
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ROUND 4
Sun (nominal diameter) vs LHS 1140 (estimated stellar diameter)
LHS 1140 · reference · 300,400 km Sun · true diameter · 1,391,000 km 4.6× wider than LHS 1140
Sun has a nominal photospheric diameter of about 1,391,400 km. This is the body’s size, not an orbital distance.
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ROUND 5
Mercury (mean diameter) vs Rhea (Saturn’s moon · mean diameter)
Rhea · reference · 1,527 km Mercury · true diameter · 4,879 km 3.2× wider than Rhea
Mercury has a mean diameter of about 4,878.8 km. This is the body’s size, not an orbital distance.
Beat these tomorrow
Every round is worth up to 100 points: within 6% of the true size scores 100, half or double scores 45, five times off scores zero. The daily puzzle is the same five for everyone and refreshes at midnight in your time zone; if you want more than five, Size It Up Unlimited draws fresh pairs from the whole library for as long as you like.