Mercury
The smallest planet and the fastest, closing an entire year in under three Earth months.
Where it is right now
Mercury is in Gemini, 0.89 AU away, magnitude 0.0.
Computed for 2 August 2026, 17:00 UTC, and recomputed at least hourly. This page is cached, so treat the line above as accurate to the hour rather than to the second. The map shows the live position.
Position from astronomy-engine's VSOP87-derived series, accurate to about an arcsecond.
Facts
Every line carries the source it came from.
- Mean radius
- 2,439.7 kmSource: NASA/JPL Planetary Fact Sheet
- Year
- 88.0 Earth daysSource: NASA/JPL Planetary Fact Sheet
- Day
- 58.6 Earth days, so three days fit in two yearsSource: NASA/JPL Planetary Fact Sheet
- Surface swing
- minus 173 C at night to 427 C at noonSource: NASA/JPL Planetary Fact Sheet
- Orbit
- 0.387 AU average, eccentricity 0.206, the most elliptical of the eightSource: NASA/JPL Approximate Positions of the Major Planets (J2000)
- Moons
- noneSource: NASA/JPL Planetary Fact Sheet
Physical size
- Mean radius
- 2,440 km
- Diameter
- 4,879 km across
Orbit
Elements are heliocentric, referred to the J2000.0 ecliptic.
- Average distance from the Sun
- 0.387 AU (57.91 million km)
- Closest and furthest
- 0.307 AU (46.00 million km) to 0.467 AU (69.82 million km)
- Eccentricity
- 0.2056, noticeably elliptical
- Inclination to the ecliptic
- 7.00 degrees
- Orbital period
- 88.0 days
- Longitude of ascending node
- 48.33 degrees
- Argument of periapsis
- 29.13 degrees
- Mean anomaly at J2000.0
- 174.79 degrees
Claim this body
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The planet takes your brand colour and carries your flag. One per planet. Leased annually.
A claim is a listing on this map. Not an IAU designation. Permanent, with one disclosed exception for dead links: see the terms.
Advertisers in orbit
Mercury carries 6 permanent orbital slots, 6 still free. Content comes first on this site: these are clearly marked and never replace a fact.
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Catalog id mercury. 3,172 objects on the map, of which 171 are hand-authored with sourced facts.