Lua question on classes and metatables?

I'm currently making a really simple solar system and would like to create a script that iterates through the planets and rotates their position depending on their radius from the sun. I think object orientated programming is the best solution for this, so I gave it a go. The following code works but I was wondering if there were simpler methods of approaching this problem.

local planet = {} --empty class for the planets
function planet.new(host, radius)
    return setmetatable({host = host, radius = radius, theta = 0}, planet)
end

local planets = {
    ["p1"] = planet.new(script.Parent.Planet1, 5, 0),
    ["p2"] = planet.new(script.Parent.Planet2, 8, 0)
}

for _,v in pairs(planets) do
    print(v.radius)
    print(v.host)
end

local sun = script.Parent.Sun.PrimaryPart
local centerGrav = sun.Position
local mass = 10 --Mass of star in 10^29 kg (Our sun is 2)
local RunService = game:GetService('RunService')

RunService.Heartbeat:connect(function()
    for _, v in pairs(planets) do
        local V_orbit = mass/(v.radius*10)
        v.theta = v.theta + V_orbit
        if v.theta >= 360 then --keeps theta within 0-360 degrees. 
            v.theta = v.theta - 360
        end
        local rads = math.rad(v.theta) --convert theta from degrees to radians (are there lua functions that accept angles in degrees?) 
        v.host.BodyPosition.Position = centerGrav + Vector3.new(v.radius*math.cos(rads), 0, v.radius*math.sin(rads))
    end
end)