All measurements are in modern terms. You will not find miles, furlongs, inches, barleycorns, cubits, acres, or spans. The calc page will convert the relevant medieval measurements for you, and has a section of stats.

Equatorial velocity is in kilometers per hour. (Note Mercury, Venus and Luna!) The calculation had to use the sidereal (star-based) "day", so that's one reason there's such a column. Solar orbit speed and "year" refer to its orbit in the galaxy. Luna and Charon are placed among the planets for two very good reasons (see "Is It A Moon?"). Note: their "distance" figures are as from Earth and Pluto, however. Masses of moons and 'tisimals are relative to Luna.

Some figures may not be the latest. Update them as you find figures that you're sure are newer. If you find new "Distances", be sure they're center-to-center, not surface-to-surface. I'll have new iterations of the sheet out as I get the new figures; and when I (or someone who writes me) think of new relationships.

Among the planetary figures, relative areas in the Earth and Sol rows are filled with their simple area in square kilos. Relative volume cells: straight cubic-kilos.

In the calculation page, enter your numbers or cell reference where a cell ends in a colon; results follow cells that end with an equals sign. If you reference a cell from a column that is headed, i.e.: "millions of kilometers", be sure to multiply that "millions" into your calculation, or otherwise allow for it. In a couple places, I provided a second cell for those entries.

The simple Kilo-to-mile conversion expanded to Kilo per HOUR and SECOND, as well.

Area of a sphere gives results in scientific notation AND plain numbers. The plain-number cell may overflow on big numbers, and the scientific may not give sufficient detail on small ones.

Relative volume is the relative mass, if you account for density.

Stuff you might use: the Roche limit is 2.44 times the planet's radius. (Inside that, a moon breaks into pieces--ergo, rings.) Volume varies with the cube of the radius; area, with the square of the diameter. Kepler's third law: the period of revolution (year) is proportional to the cube of the mean distance from the primary. "There's a torus of escaped Hydrogen in Titan's orbit.

The warmest spot on Uranus is a pole at mid-summer; 20% warmer. The Oort theory was published in 1950. Dunno what proofs or hypotheses went into it; I doubt any have been seen or detected by perturbations. They are supposedly out at 40K A.U.'s. And, surprisingly, in a sphere, not a ring.

Three Mercury days exactly equal two of its years.

There are at least 2400 'tisimals, 200 of which are over 100km diameter; 500 more are over 50km. Their total mass: xxx. Rotations: from 3 hrs to 60 days. The darkest albedo: .019 for the 'tisimal Arethusa. Darker'n a blackboard.

The Diana Chasma on Venus is two Kilo deeper'n mean elevation (280k wide). What must the air pressure be there? How much more than the average surface? On that note: would we put a permanent base at the deepest spot in Mars' Vallis Marinaris, to get that slight increase in pressure?

Jupiter's equatorial diam: 142,800. Polar: 134,200.

Saturn equatorial diam: 120,660. Polar: 108,000.

Jupiter's outer moons are so loosely held--they're chaotic, and get lost often. Amalthea, close in, is 270 by 155Km, and "points" at Jupiter. Io volcanic ejection speed: 100 M/sec; to 300 km hi. Crust 20Km thick, with tides of 100Km!! Europa gets 10% that; may have a core 1400km in diameter. Surface ridges are only 100M hi, 5-10km wide. Ganymede may've had ice-plate tectonic action.

Callisto is heaviest-cratered body in Solar system.

Jupiter's moons fall into three distinct groups: inner naturals; a group of four in orbits steeply inclined and interlaced; another group of four, far out and likewise inclined and intertwined, but retrograde. Inevitable thought: each group of four was once one, which was hit, breaking them into (at least) four pieces, and knocking their orbits cockeyed, but still roughly together.

Saturn system. Hope for Titan: surface temp: probably 95 Kelvin, near the triple-point of methane (can exist as a gas, liquid, or solid). Tethys has four co-orbitals, Dione--next door--has two, one being Helene, the orbit-swapper, at which time, they miss by only 150 km! Dione's orbit is 1:2 with Enceladus, so may get tidal warrmth. Tethys has a chasm almost all the way around-- 270 degrees; 100K wide, 4-5K deep.

Could the Galilean moons have sub-moons? Or trojans? Test it with the spreadsheet. Despite the smaller size, the best chance may be Saturn's Titan or especially Neptune's Triton-- they have no nearby gravitic competition from other moons, and plenty of debris to pick up. Besides, Triton may be exotic (that means foreign) to Neptune.

Use the calc page for hypothetical bodies; solar or of other stars. Find new relationships like Azimov's tug-of-war ratio. How close would two Oort bodies have to come to equal solar gravity and co-revolve? And especially, anything about Nemesis!

Nits: there are many planetary systems, but there's only one Solar system--because there's only one star named Sol. If there's an asteroid in the Solar system, its name is Jupiter. (Aster means "star".)

I would appreciate new ideas and formulas from you. Have you calculated something interesting? I yet need: calcs to estimate surface G's from diameter and density; trojan (any L4 or L5 point) distance from planets (60 degree angle);

Write me with any new ideas, etcetera; I need the appreciation myself. (Even if green.... it goes to Gaia.) I must have spent a hundred hours on it; more than is spent on much soft stuff you buy.

*** Especially, calculate for me anything about Nemesis! 26 million years seems at first an unlikely orbit. Is it impossible? Asimov calculated (page39) the "farthest reasonable [hypothetical] planet" (see row 15) at 126k A.U.. That's about two light years! He gave orbital speed, so I calc'd its period: 23.35 billion years! A lot; plenty of space inside that for a Nemesis. At that distance, "Farthest" is halfway to Proxima Centauri! If it's in the Galactic plane too, it'd be perturbed. (Wouldn't you?) (To be perfect, consider--in your calcs--that it orbits the combined mass of the entire solar system, including Oorts.)

To come close enough to the Oorts to "throw" them at us, it would thereafter have to fly vastly farther out. It can go out to 126K AU., so there is room for Nemesis to exist. An orbit perpendicular to the galactic plane would throw comets into wildly eccentric orbits, and we don't (currently) see this, so it's likely in the plane. Its plane might be hinted at by the average inclination of comet's orbits!

But say it's not a Nemesis. Experiment. Make it massive, and see how far a moon (planet?) could be from it!

A couple columns of categories that apply to too few bodies to include in the sheet....

Axial inclination: Sol: 7.25 degrees. Merc: essentially zero. Venus rotates retro, so they add 180 degrees, to equal 178. Pretty straight, except "upside-down". Earth: 23.44. Luna: 1.53. Mars: 23.59. Jupiter: 3.12. (Gyroscopic stabilization?) Sat: 26.73. Uranus: 97.86. (perhaps hit) Neptune: 29.56. Pluto: 50 or less.

'tisimal masses, relative to Luna: Ceres: .024; Pallas: .00749; Vesta: .00371.

Carbonaceous 'tisimals: Ceres, Pallas, Fortuna, Bamberga, Zelinda; prob'ly Deimos & Phobos.

Stony-iron: Juno, Flora, Victoria, Julia, Eros.

Basaltic Achondrite (largely iron): Vesta, Psyche, Haliope.

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