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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 b14,235.919 km
TRAPPIST-1 c13,993.551 km

Environment Comparison

Compare the size and environment of each celestial object.

MeasurementTRAPPIST-1 bTRAPPIST-1 c
Mean radius
7,118 km6,996.8 km
Diameter
≈ 14,235.9 km≈ 13,993.6 km
Spherical approximate volume
≈ 1.511E12 km3≈ 1.435E12 km3
Mass
8.206E24 kg7.812E24 kg
Mean density
5,441.939 kg/m³5,463.993 kg/m³
Surface gravity
≈ 10.81 m/s²≈ 10.65 m/s²
Escape velocity
≈ 12.4 km/s≈ 12.2 km/s
Rotation period
NaNNaN
Orbital period
1.511 d2.422 d
Mean temperature
397.6 K (124.5°C)339.7 K (66.6°C)
Surface pressure
NaNNaN
Orbital semi-major axis
1,726,359.4 km2,363,646.4 km

Mean radius

TRAPPIST-1 b
7,118 km
TRAPPIST-1 c
6,996.8 km

Diameter

TRAPPIST-1 b
≈ 14,235.9 km
TRAPPIST-1 c
≈ 13,993.6 km

Spherical approximate volume

TRAPPIST-1 b
≈ 1.511E12 km3
TRAPPIST-1 c
≈ 1.435E12 km3

Mass

TRAPPIST-1 b
8.206E24 kg
TRAPPIST-1 c
7.812E24 kg

Mean density

TRAPPIST-1 b
5,441.939 kg/m³
TRAPPIST-1 c
5,463.993 kg/m³

Surface gravity

TRAPPIST-1 b
≈ 10.81 m/s²
TRAPPIST-1 c
≈ 10.65 m/s²

Escape velocity

TRAPPIST-1 b
≈ 12.4 km/s
TRAPPIST-1 c
≈ 12.2 km/s

Rotation period

TRAPPIST-1 b
NaN
TRAPPIST-1 c
NaN

Orbital period

TRAPPIST-1 b
1.511 d
TRAPPIST-1 c
2.422 d

Mean temperature

TRAPPIST-1 b
397.6 K (124.5°C)
TRAPPIST-1 c
339.7 K (66.6°C)

Surface pressure

TRAPPIST-1 b
NaN
TRAPPIST-1 c
NaN

Orbital semi-major axis

TRAPPIST-1 b
1,726,359.4 km
TRAPPIST-1 c
2,363,646.4 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.