Donaldson R F Planet Facts Table
Every planet, Pluto and the Moon, with the same facts side by side: mass, size, gravity, distance from the Sun, orbit and more. Pick two to compare directly.
All figures are metric, as published. "Retrograde" spin (Venus, Uranus, Pluto) means the planet turns backwards compared with most others.
How to read the table
Mass is in 1024 kg (Earth is about 6, Jupiter is about 1,898 — over 300 times Earth's mass). Gravity is the pull you would feel standing on the surface; see the Planet Weight Calculator to turn that into your own weight. Distance from the Sun and the orbital period (the planet's "year") are averages, since every orbit is a slightly stretched ellipse between its closest point (perihelion) and farthest (aphelion). The Moon's row is the odd one out: its distance, orbital period and speed are relative to the Earth, not the Sun, because it orbits us rather than the Sun directly.
Rotation and "length of day"
The rotation period is how long the planet takes to spin once on its axis. The length of day is different: it is how long the Sun takes to return to the same position in the sky, which also depends on how far the planet has moved around its orbit in that time. For Mercury and Venus, which spin very slowly, this makes a big difference — Mercury's day is almost three times longer than its year is short.
Frequently asked questions
Why is Pluto included if it is not a planet any more?
Pluto was reclassified as a dwarf planet in 2006, but it is still commonly compared alongside the planets, and NASA's own fact sheet (the source below) includes it for that reason.
Why does Jupiter's surface pressure say "unknown"?
The gas giants (Jupiter, Saturn, Uranus, Neptune) have no solid surface, so a surface pressure cannot be measured the way it can on a rocky planet; the source lists it as unknown rather than guessing.
Related tools: Planet Weight Calculator, Age on Other Planets, Light Travel Time Calculator.
Source / Last verified: NASA/GSFC, "Planetary Fact Sheet – Metric" (nssdc.gsfc.nasa.gov/planetary/factsheet), a page the site itself marks "Last Updated: 18 March 2025, DRW". Figures copied and checked against that page on 27 September 2026.