# -----------------------------------------------------------------------------
# DEFINING CONSTANTS
# -----------------------------------------------------------------------------

export μs, G, GMs, μ, rs, as, es, AU, ids

# Gravitational Constants
  μs = Dict(
  "Sun" => 1.32712440018e11,
  "Mercury" => 2.2032e4,
  "Venus" => 3.257e5,
  "Earth" => 3.986004415e5,
  "Moon" => 4.902799e3,
  "Mars" => 4.305e4,
  "Jupiter" => 1.266865361e8,
  "Saturn" => 3.794e7,
  "Uranus" => 5.794e6,
  "Neptune" => 6.809e6,
  "Pluto" => 9e2)

  G = 6.67430e-20

  function μ(m1::Float64, m2::Float64)
    return m2/(m1+m2)
  end

  function μ(GM1::Float64, GM2::Float64, Grav::Float64)
    return μ(GM1/Grav, GM2/Grav)
  end

  function μ(primary::String, secondary::String)
    return μ(GMs[primary]/G, GMs[secondary]/G)
  end

  const GMs = Dict(
  "Sun" => 132712440041.93938,
  "Earth" => 398600.435436,
  "Moon" => 4902.800066)

# Radii
  const rs = Dict(
  "Sun" => 696000.,
  "Mercury" => 2439.,
  "Venus" => 6052.,
  "Earth" => 6378.1363,
  "Moon" => 1738.,
  "Mars" => 3397.2,
  "Jupiter" => 71492.,
  "Saturn" => 60268.,
  "Uranus" => 25559.,
  "Neptune" => 24764.,
  "Pluto" => 1151.)

# Semi Major Axes
  const as = Dict(
  "Mercury" => 57909083.,
  "Venus" => 108208601.,
  "Earth" => 149598023.,
  "Moon" => 384400.,
  "Mars" => 227939186.,
  "Jupiter" => 778298361.,
  "Saturn" => 1429394133.,
  "Uranus" => 2875038615.,
  "Neptune" => 4504449769.,
  "Pluto" => 5915799000.)

# Eccentricities
  const es = Dict(
  "Earth" => 0.016708617,
  "Moon" => 0.0549)

# J2 for basic oblateness
  const j2s = Dict(
  "Mercury" => 0.00006,
  "Venus" => 0.000027,
  "Earth" => 0.0010826269,
  "Moon" => 0.0002027,
  "Mars" => 0.001964,
  "Jupiter" => 0.01475,
  "Saturn" => 0.01645,
  "Uranus" => 0.012,
  "Neptune" => 0.004,
  "Pluto" => 0.)

# These are just the colors for plots
  const p_colors = Dict(
  "Sun" => "Electric",
  "Mercury" => "heat",
  "Venus" => "turbid",
  "Earth" => "Blues",
  "Moon" => "Greys",
  "Mars" => "Reds",
  "Jupiter" => "solar",
  "Saturn" => "turbid",
  "Uranus" => "haline",
  "Neptune" => "ice",
  "Pluto" => "matter")

  const ids = Dict(
    "Sun" => 10,
    "Mercury" => 1,
    "Venus" => 2,
    "Earth" => 399,
    "Moon" => 301,
    "Mars" => 4,
    "Jupiter" => 5,
    "Saturn" => 6,
    "Uranus" => 7,
    "Neptune" => 8,
    "Pluto" => 9,
  )

  const AU = 149597870.691 #km
  const init_STM = vec(Matrix{Float64}(I,6,6))