ALL ANSWERS · SPACE · DAILY No. 44 · OCTOBER 17, 2026
Size It Up Space answer: October 17
The five Space silhouettes for October 17, 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 44 ran from Deimos (12.4 km) to GJ 436 (633,100 km). The widest gap was round 5, Ariel against Europa, at 2.7×; the closest call was round 3, K2-18 against GJ 436, only 1.1× 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
Deimos (Mars’s moon · mean diameter) vs Atlas (Saturn’s moon · mean diameter)
Atlas · reference · 30.2 km Deimos · true diameter · 12.4 km 2.4× shorter than Atlas
Deimos, a moon of Mars, has a mean diameter of about 12.4 km. This is the body’s size, not an orbital distance.
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ROUND 2
Earth (mean diameter) vs Mercury (mean diameter)
Mercury · reference · 4,879 km Earth · true diameter · 12,740 km 2.6× wider than Mercury
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 3
K2-18 (estimated stellar diameter) vs GJ 436 (estimated stellar diameter)
GJ 436 · reference · 633,100 km K2-18 · true diameter · 571,900 km 1.1× shorter than GJ 436
K2-18 has an estimated stellar diameter of about 571,865.4 km. This is the body’s size, not an orbital distance.
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ROUND 4
Rhea (Saturn’s moon · mean diameter) vs Pluto (mean diameter)
Pluto · reference · 2,377 km Rhea · true diameter · 1,527 km 1.6× shorter than Pluto
Rhea, a moon of Saturn, has a mean diameter of about 1,527 km. This is the body’s size, not an orbital distance.
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ROUND 5
Ariel (Uranus’s moon · mean diameter) vs Europa (Jupiter’s moon · mean diameter)
Europa · reference · 3,122 km Ariel · true diameter · 1,158 km 2.7× shorter than Europa
Ariel, a moon of Uranus, has a mean diameter of about 1,157.8 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.