Mercury

E18768

Mercury is the smallest and innermost planet in our Solar System, known for its extreme temperature variations and heavily cratered surface.

Aliases (2)

Statements (65)
Predicate Object
instanceOf astronomical object
inner planet
planet
terrestrial planet
albedoBond about 0.12
atmosphereType exosphere
atmosphericComponent helium
hydrogen
oxygen
potassium
sodium
axialTilt about 0.03 degrees
belongsToCategory innermost planet in the Solar System
smallest planet in the Solar System
canTransitSunFromEarth yes
colorAppearance dark gray
coreComposition large metallic core
coreState partly molten core
crustComposition silicate rock
density_mean about 5.43 grams per cubic centimeter
diameter_mean about 4,880 kilometers
discoveredBy prehistoric astronomers
distanceFromSun_mean about 0.39 astronomical units
about 57.9 million kilometers
escapeVelocity about 4.25 kilometers per second
exploredBy BepiColombo
MESSENGER
Mariner 10
firstFlybyBy Mariner 10
firstFlybyYear 1974
firstOrbiter MESSENGER
firstOrbiterArrivalYear 2011
hasAtmosphere yes
hasMagneticField yes
hasNaturalSatellite no known moons
hasWaterIce yes
magneticFieldStrength_surface about 1% of Earth’s
magneticFieldType global dipolar magnetic field
mass about 3.30 × 10^23 kilograms
maxSurfaceTemperature about 430 degrees Celsius
meanSurfaceTemperature about 167 degrees Celsius
memberOf inner Solar System
minSurfaceTemperature about −180 degrees Celsius
namedAfter Mercury (Roman god)
observedFrom Earth
orbitalEccentricity about 0.2056
orbitalInclinationToEcliptic about 7 degrees
orbitalPeriod about 88 Earth days
partOf Solar System
positionFromSun first planet from the Sun
radius_mean about 2,440 kilometers
rotationOrbitResonance 3:2 spin–orbit resonance
siderealRotationPeriod about 58.6 Earth days
solarDayLength about 176 Earth days
surfaceArea about 7.5 × 10^7 square kilometers
surfaceFeature Caloris Basin
Rupes (scarps)
heavily cratered highlands
intercrater plains
smooth plains
surfaceGravity about 3.7 meters per second squared
transitFrequencyApprox about 13 times per century
visibleTo naked eye
volume about 6.1 × 10^10 cubic kilometers
waterIceLocation permanently shadowed polar craters


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