About Ganymede
Ganymede is an epic moon.
It orbits about 5.2 AU from the Sun — roughly 5.2 times Earth's distance.
Epic moon 60 EP
Ganymede
Position computed live · planets
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Live ephemeris
This object moves — fetching its current position…
Score breakdown
· 5 badgesEpic 78 pts → Anomaly
- Subsurface ocean +18
- Moon +16
- Largest moon in the system +12
- Has a proper name +8
- Tidally locked +6
Total score 60
18 more points to reach Anomaly.
Badges
- Moon · +16
- Has a proper name · +8
- Subsurface ocean · +18
- Largest moon in the system · +12
- Tidally locked · +6
Trivia
Hard to believe
- Round under its own weight. Big enough that its own gravity has pulled it into a sphere — most of its neighbours are potato-shaped rubble.
- Biggest moon there is. The largest moon in the Solar System — wider than the planet Mercury, and the only moon known to generate a magnetic field of its own.
What it actually is
- Its address. It orbits about 5.2 AU from the Sun — roughly 5.2 times Earth's distance.
- Around its planet. It circles its planet at a distance of 1.1 million km — roughly 2.8 times the Earth–Moon gap — coming right round once every 7.2 days.
Sense of scale
- Against Earth. It is only 41% of Earth's width — you could pack about 14.1 of it inside our planet.
- Ground to cover. Its whole surface adds up to about 87.2 million km² — about 59% of Earth's dry land.
- Walk around it. Walking right round its equator, eight hours a day, would take about 13.6 months.
Time and light
- Sunrise is late. Sunlight takes about 43.3 minutes to get there, against eight minutes to reach us.
Properties
- color
- #9c8f7c
- diameter km
- 5268.2
- largest moon
- yes
- name
- Ganymede
- named
- yes
- radius km
- 2634.1
- subsurface ocean
- yes
- tidally locked
- yes
How to see it
Like any astronomical target, Ganymede is best seen from a dark site away from city lights, and when it is above the horizon depends on your latitude and the time of year. Because it moves against the background stars, the live position panel on this page tracks where it is right now. The visibility panel above works out tonight's viewing window for your saved location.
Why Ganymede is an epic moon
Ganymede scores 60 points on Spacedle's rarity scale, which places it in the epic tier. Another 18 points would lift it into a rarer tier.
That score comes from 5 science badges — Moon, Has a proper name, Subsurface ocean, Largest moon in the system and Tidally locked — each earned for a real, measurable property of the object. Rarity on Spacedle is never random: the more remarkable an object's astrophysics, the more badges it collects, the higher it scores, and the rarer it ranks.