← Daily Dose The Grand Tour — a solar system in numbers · Daily Dose No. 014
Daily Dose  /  Aug 5, 2026  /  The Solar System

The Grand Tour,
in numbers

Eight planets, one star, and a lot of empty space. Measured honestly, the solar system is less a family of worlds than a single enormous Sun with some debris in orbit — and the debris is stranger, colder, hotter and further away than almost anyone pictures. Here is the whole neighbourhood, to scale, in the only units that don't flatter it.

Share of all mass held by the Sun
99.86%

Add up every planet, moon, asteroid, comet and grain of dust in the solar system and you get 0.14% of its mass. Two-thirds of that leftover is Jupiter alone. Everything humans have ever seen, touched or lived on is a rounding error orbiting a star. Derived from NASA NSSDCA body masses (2024)

01 · The map

Nothing about the solar system is drawn to scale

The four rocky planets huddle inside 1.5 astronomical units. Then comes a gap, and the giants spread out across thirty. Plotted on a logarithmic axis — the only way they fit on a page — the inner solar system compresses into the first fifth of the line.

1 AU 10 AU 100 AU Main belt 2.2–3.2 AU Kuiper belt 30–50 AU Sun Mercury Venus Earth Mars Jupiter Saturn Uranus Neptune Heliopause ~120 AU Voyager 1 173 AU
Schematic locator map, logarithmic distance axis. Body sizes indicative, not to scale. Sources: NASA NSSDCA Planetary Fact Sheet (2024); NASA/JPL Voyager mission status (2026).
02 · Distance

How long the sunlight takes to arrive

Kilometres are meaningless out here. Time is not. Sunlight reaches Mercury in about three minutes and Neptune in a little over four hours — and a radio signal to Voyager 1 now needs the better part of a day, one way.

Mercury 3.2 min 0.39 AU Venus 6.0 min 0.72 AU Earth 8.3 min 1.00 AU Mars 12.7 min 1.52 AU Jupiter 43.3 min 5.20 AU Saturn 1 h 20 m 9.58 AU Uranus 2 h 40 m 19.2 AU Neptune 4 h 10 m 30.1 AU Voyager 1 ~23 h 173 AU Signature spectrum strip — one hue, light to dark, ordered by distance from the Sun. Positions are ordinal, not linear.
Light-travel times computed from NASA NSSDCA mean orbital distances ÷ 299,792 km/s. Sources: NASA NSSDCA Planetary Fact Sheet (2024); NASA/JPL (2026).
03 · Mass

Jupiter, and then everyone else

Jupiter carries 318 Earths of material — roughly two and a half times the mass of the other seven planets put together. Below it the scale falls off a cliff: Mercury is one eighteenth of an Earth. A logarithmic axis is the only way to show them on one chart.

0.01 0.1 1 10 100 1,000 MASS IN EARTH MASSES — LOGARITHMIC SCALE Jupiter 317.8 Saturn 95.2 Neptune 17.1 Uranus 14.5 Earth 1.00 Venus 0.815 Mars 0.107 Mercury 0.055
Ratios computed from NASA NSSDCA masses (Earth = 5.97×10²⁴ kg). Jupiter's 1,898×10²⁴ kg is 2.5× the combined mass of the other seven planets. Source: NASA NSSDCA Planetary Fact Sheet (2024).
04 · Conditions

A 664-degree spread, and one planet that crushes

Mean surface temperatures across the eight planets span from Neptune's −200 °C to Venus's 464 °C. Venus is hotter than Mercury despite being twice as far from the Sun — its carbon-dioxide atmosphere traps the heat and presses down at 92 bar.

−200 −100 0 °C 100 300 500 Venus +464 °C Mercury +167 Earth +15 Mars −65 Jupiter −110 Saturn −140 Uranus −195 Neptune −200
Mean temperatures; local extremes are wider still. Sources: NASA NSSDCA Planetary Fact Sheet (2024); NASA Venus Facts (2024).
92 bar
Venus surface pressure
The same crush you'd feel about 900 m (3,000 ft) beneath Earth's ocean. Soviet landers survived minutes, not hours. NASA, 2024
21.9 km
Olympus Mons, Mars
The tallest volcano known anywhere — roughly 2.5× the height of Everest above sea level, on a planet half Earth's width. NASA / USGS
98°
Uranus axial tilt
Uranus orbits on its side, so each pole gets 42 straight Earth-years of sunlight and then 42 of darkness. NASA NSSDCA
05 · Time

On Venus, a day is longer than a year

Venus turns on its axis once every 243 Earth days — backwards — while completing an orbit in 224.7. It is the only planet where the rotation outlasts the revolution. At the other end, Jupiter spins once in under ten hours, and Neptune needs 164 Earth years to go round once.

0 50 100 150 200 250 EARTH DAYS One Venus rotation 243.0 d One Venus year 224.7 d
Sidereal rotation period vs orbital period; Venus's rotation is retrograde. A Venus solar day — sunrise to sunrise — is 117 Earth days. Source: NASA NSSDCA Planetary Fact Sheet (2024).
9.9 hrs
Shortest day — Jupiter
The largest planet is also the fastest spinner, which is why it bulges visibly at its equator.
164 yrs
Longest year — Neptune
Discovered in 1846, Neptune completed its first full orbit since discovery in 2011.
88 days
Shortest year — Mercury
And its solar day lasts 176 Earth days — two Mercury years pass between sunrises.
06 · Moons

We keep finding more of them

Saturn had 17 known moons when Voyager flew past. Better surveys — not new moons — have pushed the count past 270, and the solar system's confirmed total is now above 890.

300 200 100 0 1980 2000 2019 2025 KNOWN MOONS OF SATURN 17 · 1980 30 · 2000 82 · 2019 146 · 2023 274 March 2025
A single 2025 survey led by Edward Ashton added 128 moons at once. The IAU Minor Planet Center has since logged further Saturnian satellites, taking the count above 290 in 2026. Sources: NASA Solar System Moons (Mar 2025); IAU Minor Planet Center (2026).
891+
Confirmed moons, solar system
421 orbiting planets and Pluto; 470+ orbiting dwarf planets, asteroids and trans-Neptunian objects. NASA, Mar 2025
4%
Asteroid belt mass vs the Moon
The entire main belt weighs about 3×10²¹ kg — a twenty-fifth of our Moon. Ceres alone is a third of it. NASA Dawn / NASA Science
2
Moons of Mars
Phobos and Deimos — both smaller than Manhattan is long, and both probably captured asteroids. NASA NSSDCA
07 · Reach

What it costs to actually go there

The distances above are not abstractions — they are mission budgets, measured in decades. Our fastest object took seven Venus flybys to build up speed; our furthest took half a century to get one light-day from home.

692,000
km/h · Parker Solar Probe
The fastest speed ever reached by a human-made object, at perihelion on 24 Dec 2024, when it passed 6.1 million km from the Sun's surface. NASA / JHUAPL, 2024
9.5 yrs
Earth to Pluto · New Horizons
Launched Jan 2006, flyby July 2015 — and the encounter itself lasted a matter of hours. NASA New Horizons
1 light-day
Voyager 1 · 18 Nov 2026
25.9 billion km, or 173.1 AU, reached after 49 years of continuous flight. A command sent now arrives tomorrow. NASA/JPL, 2026
Why it matters

Scale is the whole story

Almost every mental image of the solar system is a lie of convenience: planets drawn the same size, orbits drawn evenly spaced, the Sun shrunk to fit the page. The real numbers say something else — that the Sun is essentially the entire system, that the gaps between worlds are measured in hours of lightspeed, and that we are still discovering hundreds of objects in our own back yard.

If you want to feel it rather than read it: on a scale where Earth is a peppercorn, the Sun is a beach ball two city blocks away, and Neptune is a further two kilometres out. That walk is the honest version of this diagram.

Everything that has ever happened to a human being has happened inside 0.14% of the solar system's mass.

Sources & notes

  1. NASA NSSDCA — Planetary Fact Sheet (metric), 2024. Masses, diameters, mean distances, rotation and orbital periods, mean temperatures, surface pressure, axial tilt for all eight planets.
  2. NASA Science — Venus Facts, 2024. Surface pressure ≈ 92 bar, equivalent to roughly 900 m (3,000 ft) below Earth's ocean surface; mean temperature 464 °C.
  3. NASA Science — Solar System Moons, 25 March 2025. More than 891 confirmed moons: 421 orbiting planets and Pluto, 470+ orbiting dwarf planets, asteroids and trans-Neptunian objects; Saturn at 274.
  4. IAU Minor Planet Center, 2026. Additional Saturnian satellites announced 16 March and 9 April 2026, taking Saturn's confirmed count above 290.
  5. Ashton et al. / Canada–France–Hawaii Telescope survey, 2025. 128 new Saturnian moons announced in a single batch.
  6. NASA / Johns Hopkins APL, 24 December 2024; record ratified by Guinness World Records. Parker Solar Probe at 692,000 km/h (430,000 mph), 6.1 million km from the solar surface.
  7. NASA/JPL — Voyager mission status, 2026. Voyager 1 reaches one light-day from Earth on 18 November 2026: 25.9 billion km / 173.1 AU; one-way signal time ≈ 23 hours in mid-2026.
  8. NASA New Horizons. Launched 19 January 2006, Pluto closest approach 14 July 2015 — 9.5 years.
  9. NASA / USGS Astrogeology. Olympus Mons ≈ 21.9 km tall; Valles Marineris ≈ 4,000 km long.
  10. NASA Science / Dawn mission. Main-belt total mass ≈ 3×10²¹ kg, about 4% of the Moon's mass; Ceres holds roughly one third of it.

Notes on derived figures: the Sun's 99.86% mass share, all light-travel times, all Earth-mass ratios, and the statement that Jupiter exceeds the other seven planets combined by ~2.5× are arithmetic performed on NASA NSSDCA values, not separately measured quantities. Planetary mean temperatures are global averages; local extremes are far wider. Moon counts are inherently provisional and rise with every survey. Distances are mean orbital distances; actual separations vary with orbital position. The "peppercorn" comparison in the closing section is an illustrative scale model, not a measurement.

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