Solar System records
Biggest, smallest, hottest and fastest – records from the NASA/JPL data behind the map. “In our catalogue” means among the bodies described on this site.
Size and mass
- Largest planet Jupiter 142,984 km diameter – 11.2 times Earth’s Source: NASA Planetary Fact Sheet
- Smallest planet Mercury 4,879 km diameter Source: NASA Planetary Fact Sheet
- Largest moon Ganymede 5,262 km diameter – larger than the planet Mercury (4,879 km) Source: JPL SSD – Planetary Satellites
- Smallest moon in our catalogue Styx 10.4 km diameter (radius from JPL); many smaller moons are known – we describe 40 of them Source: JPL SSD – Planetary Satellites
- Strongest “surface” gravity Jupiter 23.1 m/s² 2.4 times Earth’s; a gas giant has no solid surface – the value is at the 1-bar pressure level Source: NASA Planetary Fact Sheet
- Densest planet Earth 5,514 kg/m³ mean density Source: NASA Planetary Fact Sheet
- Lowest density Saturn 687 kg/m³ less than water (1000 kg/m³) Source: NASA Planetary Fact Sheet
- Most known moons Saturn 274 according to the NASA Planetary Fact Sheet; the number grows with new discoveries Source: NASA Planetary Fact Sheet
Temperature and surface
- Hottest surface Venus 464 °C mean temperature – hotter than Mercury, which is closer to the Sun (167 °C), because of the greenhouse effect Source: NASA Planetary Fact Sheet
- Lowest mean temperature Pluto -225 °C among the bodies in the NASA Planetary Fact Sheet Source: NASA Planetary Fact Sheet
- Largest volcano Mars over 40 km Olympus Mons on Mars – according to NASA the largest volcano in the Solar System, over 40 km from base to summit Source: NASA Science – Mars Facts
- The planet “lying on its side” Uranus 97.8° axial tilt – each pole spends decades in daylight, then decades in darkness Source: NASA Planetary Fact Sheet
Day, year and orbit
- Shortest day Jupiter 9.9 h noon to noon Source: NASA Planetary Fact Sheet
- Longest solar day Mercury 175.9 days longer than its year (88 days): two orbits pass from one sunrise to the next Source: NASA Planetary Fact Sheet
- Slowest rotation Venus 243.0 days (retrograde) rotation period against the stars – and in the opposite direction to most planets Source: NASA Planetary Fact Sheet
- Shortest year Mercury 88 days orbital period around the Sun Source: NASA Planetary Fact Sheet
- Longest planetary year Neptune 163.7 years orbital period around the Sun Source: NASA Planetary Fact Sheet
- Fastest planet Mercury 47.4 km/s mean orbital speed Source: NASA Planetary Fact Sheet
- Most elongated planetary orbit Mercury 0.206 eccentricity – 46.00 million km from the Sun at perihelion, 69.80 million km at aphelion Source: NASA Planetary Fact Sheet
Today 4 November 2026
- Planet closest to Earth today Venus 42.92 million km changes from day to day – Earth and the planets orbit at different speeds Source: NASA/JPL – orbital elements
- Farthest from the Sun in our catalogue today Eris 95.61 AU 14.30 billion km from the Sun Source: NASA/JPL – orbital elements
- Most distant spacecraft Voyager 1 25.77 billion km 172.2 AU from the Sun; light from there takes 23 h 53 min Source: JPL Horizons
Figures from NASA and JPL tables – public domain. The “Today” cards are calculated for the start of the day (UTC) with the same model as the map.
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