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At a Glance

Celestial Size Comparison

Choose the celestial objects you’re curious about. See at a glance how their sizes and environments compare.

Choose objects to compare

Choose at least 2 and no more than 4 celestial objects.

2/ 4

TRAPPIST-1 System objects

8 objects
TRAPPIST-1Star
TRAPPIST-1 bPlanet
TRAPPIST-1 cPlanet
TRAPPIST-1 dPlanet
TRAPPIST-1 ePlanet
TRAPPIST-1 fPlanet
TRAPPIST-1 gPlanet
TRAPPIST-1 hPlanet

Size Comparison

Shows objects at a scale close to their actual size ratio.

TRAPPIST-1 d10,051.886 km
TRAPPIST-1 h9,630.931 km

Environment Comparison

Compare the size and environment of each celestial object.

MeasurementTRAPPIST-1 dTRAPPIST-1 h
Mean radius
5,025.9 km4,815.5 km
Diameter
≈ 10,051.9 km≈ 9,630.9 km
Spherical approximate volume
≈ 531,791,307,376 km3≈ 467,738,842,439 km3
Mass
2.317E24 kg1.947E24 kg
Mean density
4,366.784 kg/m³4,162.78 kg/m³
Surface gravity
≈ 6.123 m/s²≈ 5.604 m/s²
Escape velocity
≈ 7.8 km/s≈ 7.3 km/s
Rotation period
NaNNaN
Orbital period
4.049 d18.773 d
Mean temperature
286.2 K (13.1°C)171.7 K (-101.4°C)
Surface pressure
NaNNaN
Orbital semi-major axis
3,331,544.6 km9,258,612.2 km

Mean radius

TRAPPIST-1 d
5,025.9 km
TRAPPIST-1 h
4,815.5 km

Diameter

TRAPPIST-1 d
≈ 10,051.9 km
TRAPPIST-1 h
≈ 9,630.9 km

Spherical approximate volume

TRAPPIST-1 d
≈ 531,791,307,376 km3
TRAPPIST-1 h
≈ 467,738,842,439 km3

Mass

TRAPPIST-1 d
2.317E24 kg
TRAPPIST-1 h
1.947E24 kg

Mean density

TRAPPIST-1 d
4,366.784 kg/m³
TRAPPIST-1 h
4,162.78 kg/m³

Surface gravity

TRAPPIST-1 d
≈ 6.123 m/s²
TRAPPIST-1 h
≈ 5.604 m/s²

Escape velocity

TRAPPIST-1 d
≈ 7.8 km/s
TRAPPIST-1 h
≈ 7.3 km/s

Rotation period

TRAPPIST-1 d
NaN
TRAPPIST-1 h
NaN

Orbital period

TRAPPIST-1 d
4.049 d
TRAPPIST-1 h
18.773 d

Mean temperature

TRAPPIST-1 d
286.2 K (13.1°C)
TRAPPIST-1 h
171.7 K (-101.4°C)

Surface pressure

TRAPPIST-1 d
NaN
TRAPPIST-1 h
NaN

Orbital semi-major axis

TRAPPIST-1 d
3,331,544.6 km
TRAPPIST-1 h
9,258,612.2 km
Please Note

This comparison is based on the most reliable observational data available. Celestial information may change with new research and observations, so please treat it as a general guide rather than a definitive source.