A 900-metre rubble pile that has been brought back to Earth in a jar.
Hayabusa2 ONC-T
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58.1/100 · Severe
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Escape velocity
0.4 m/s
Walking briskly would launch you into space. Everything on the surface, including a lander, has to be actively held down.
Surface conditions on Ryugu
Every figure below is tagged with where it came from. Measured means an instrument read it on or at the body; modeled means it was computed and never directly observed.
GravityMeasured
0.00 m/s²
0.000 g
Mean temperatureMeasured
-27 °C
-63 to 100 °C
Surface pressureMeasured
Vacuum
None
RadiationModeled
0.700 mSv/day
Unshielded interplanetary GCR near 1 AU
Solar fluxModeled
960 W/m²
0.71x Earth
Day / night cycleMeasured
7.6 h
Hayabusa2 imaging
Water
None
Travel timeMeasured
3.6 years
Hayabusa2, Dec 2014 to Jun 2018
Delta-v from LEOModeled
5.2 km/s
Near-Earth asteroid rendezvous — cheaper to reach than the lunar surface
Radius
0.448 km
0.000x Earth
What it would take to settle Ryugu
No world off Earth is habitable — the honest habitable fraction of every surface here is zero. What can be answered is how far each one sits from Earth along the seven axes a habitat has to buy its way out of. Ryugu scores 58.1 out of 100, on 100% coverage of the axes. The single worst axis here is pressure (Vacuum); the one that most sets Ryugu apart from the other thirteen is water.
Radiation30
Pressure100
Temperature15
Gravity98
Water100
Available energy7
Access49
Pressure
Vacuum
Below the Armstrong limit (0.062 bar) body fluids boil at body temperature — the difference between needing a mask and needing a pressure vessel. Above 1 bar the problem inverts into containment, and Venus at 92 bar has never let a lander live two hours.
Gravity
0.00 m/s² — 0.000 g
Nobody has ever measured long-term human health at any gravity between 0 and 1 g. Below about 0.1 g, anchoring anything — including yourself — becomes the design driver.
Water
None
Water is drinking water, breathing oxygen and rocket propellant in one deposit. A world without it has to import all three forever.
Access
5.2 km/s from LEO, 3.6 years one way
Delta-v sets what a launch costs; cruise time sets how much consumable, shielding and crew patience each kilogram of payload drags with it.
Who has been to Ryugu
Human landings
0
People who walked
0
Robotic landings
4
Named features
13
Hayabusa2 touched down twice, dropped two MINERVA-II rovers and the MASCOT lander, blew a crater in it with a copper impactor, and flew 5.4 grams of it home in December 2020.
Unprotected survival: Seconds. You would also have to be careful not to jump off.
Water
No ice, but the returned samples are 7% water by mass, locked in hydrated clays — plus amino acids, making Ryugu direct evidence for how water reached Earth.
The named places on Ryugu
The IAU has approved 13 names on Ryugu, each drawn from a theme the naming committee chose for this world. Every name in the scene above is one of them, placed at its catalogued coordinates.
Imagery is public-domain NASA/USGS mission data, streamed live from NASA Trek as a plate-carrée tile pyramid and draped on our own sphere — no third-party globe library and no cached copy of anyone else's map.
